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Contents: |
Date: Tue, 08 Sep 1998 11:02:29 +0000
From: Kyrre Aalerud,
Subject: Minilinux fails to load X11
I am out of ideas...
I am trying to get Mini-Linux to load the accompanied X11, but i get a error about some directory or file that dows not exist, and a "Unexpected signal 13" error... What am I forgetting... Is there anything special I have to load to get the D.. thing to work ?
PS: I cant find any CDrom-devices either.... (I have looked in etc and averywhere else but...)
h.e.l.p.....
Kyrre
Date: Sun, 06 Sep 1998 23:29:09 -0400
From: Nathaniel Smith,
Subject: Lost newbe
I find it hard to believe that every one thinks that all people know how to operate linux perfectly, and that all are born with this information. This must be the case for I cannot find a site on the web that teaches you how to operate Linux (and I am desperate to find one), I have run into people using windows 95&98 (12 people) that would like to try Linux but cant find out how to operate it (there is a real good deal at best buy on Red Hat Linux) so I bought it and a new Western Digital hard drive to put it on, though my trying to find somewhere that teaches Linux, I came upon an article that says you can have Linux and windows on the same computer while learning Linux, and after learning you can delete windows. Sooooooo how about giving us articles on how to utilize this great OS, and help hundreds us poor lost souls that are desperate. thank you Nathaniel alias poor lost desperate newbe
Date: Thu, 03 Sep 1998 15:04:43 -0600
From: Hugh Shane,
Subject: Booting from LS120 disk drives
I know this information is out there somewhere, but I'd like to hear from anyone who has successfully gotten an x86 Linux machine to boot from an LS120 disk drive.
Hugh
Date: Wed, 02 Sep 1998 23:01:25 +0800
From: Lye On Siong,
Subject: some qn
Just like to ask a few questions.
My CD-ROM is on /dev/hdd. When I want to mount it, it tells me that it's not a block device. (previously, it was running fine.. dunno what happen)
How can my Linux kernel support PPP? How do I recompile my kernel to make it work?
Johnny
Date: Thu, 10 Sep 1998 02:03:46 +0530 (IST)
From: M Anand,
Subject: proxy
How do I set the proxy server for lynx and irc in Red-Hat Linux 5.1/SuSE Linux 5.1?
Anand
Date: Thu, 17 Sep 1998 01:25:44 PDT
From: parmentier remy,
Subject: Help : Modem + HP
I am close to commiting suicide!
I have already spent hours trying to fix my Supra336 PnP internal modem and my HP DeskJet 720C under Linux!
The result is always the same, no communication with teh modem and no page printed on the HP printer!
Could someone help me, I am close to abandon!
Thank you for answering. ( I use the RedHat 5.1 distribution )
Date: Tue, 15 Sep 1998 13:35:01 -0400
From: Taylor Sutherland,
Subject: Canon BJC-250 question
I have a Canon BJC-250 color printer. I have heard many people say that the BJC-600 printer driver will let me print in color. But I have not heard anyone say where I can get such a driver. I have looked everywhere but where it is. Can you help me?
Thank you.
Taylor Sutherland
Date: Tue, 25 Aug 1998 18:39:03 -0600 (CST)
From: Dion Rowney,
Subject: Article Suggestion
I just had a nasty problem this morning. I had recompiled my kernel the night before and forgot to tell lilo where it was. In the morning I found it sitting at the "loading linux ..." prompt hung. My idea would be help on getting around this problem, maybe a little about how lilo knows where the boot kernel is, recovering easily from this mistake (a good idea since as usual I chose the difficult way).
Just am idea because I felt like a tool because I had no idea how it could be fixed, aside from reinstalling or upgrading using the boot install disks.
Thanks,
Dion Rowney
Date: Tue, 22 Sep 1998 11:51:10 +0200
From: Jan Jansta,
Subject: Problem mounting vfat filesystem ...
I have permanent problem with mounting any vfat/dos filesystem with write permisions for all users on my Linux machine. I'm using RedHat 5.1, kernel version 2.0.34
I've already tried -
mount -t vfat -o mode=0777 /dev/hdb1 /dosI've also tried to change permisions for /dos via
chmod 777 /dosIt didn't work as well.
Does someone know what's not working properly ?
Last month I printed a letter from Hugo van der Kooij in which he asked me to quit using the word "Damn" in the Table of Contents of Linux Gazette. I said I would put it to a vote. Well, I received quite a bit of mail on this issue, and the vote was essentially 6 to 1 in favor of keeping this word.
That said, I intend to renege on my statement that I would abide by the vote. Much of the mail I received is not printable, and some of it is quite entertaining. The best, most well-thought out answer I received is printed directly below, and this letter alone convinced me that I should accede to Hugo's request. From now on I intend to call that section containing the entire issue TWDT -- this is the best compromise I could think of. We all know what TWDT stands for, it will just not be printed there. Newcomers may be a bit confused but they'll survive.
Enough said. This is my final decision, so please don't write asking me to change my mind. As many reminded me, we have more important things to spend our time considering, such as helping others to learn and love Linux as we do.
Marjorie Richardson, Overseer, Editor and now Ruler of Linux Gazette :-)
Date: Wed, 2 Sep 1998 15:12:55 +0800
From: Mark Harrison,
Subject: Drop the "Damn"
Given his e-mail address, there is a reasonable chance that Hugo van der Kooij may be a member of the Dutch Reformed Church, probably one of the most strict Protestant denominations.
They are generally quite excellent people (most of the Dutch nationals imprisoned by the Nazis for sheltering Jews were in this denomination, following their [correct] interpretation of the Bible.). They are also very strict in observing proper behavior, such as no swearing.
I don't advocate a wholesale removal of the various naughty words from the culture (The title of Audie Murphy's famous book summed up his experiences perfectly), but for this case, I see no harm in dropping the offending word.
Mark Harrison, Beijing, China
Date: Wed, 09 Sep 1998 14:03:04 +0200
From: Sean Mota,
Subject: links between identical sections
Now and then I've found myself reading an article in an issue of the gazette and thinking of a past article that I read in a previous issue, both belonging to the same section (normally the Graphics Muse). Since I would like to read again that past article and I never remember in which issue it was published, I have to go to the main page, select an issue an view the table of contents, and finally click on the section I'm interested in. It would be much quicker if "last"/"next" buttons between articles of different issues but belonging to the same section were available. That way, if I were reading the Graphics Muse's article of this month and he mentions something about OpenGL, I might remember there was an article on this subject (OpenGL) a couple of past issues; then, with the aid of the "last" button, I would start reviewing past articles of the Graphics Muse until I found the one I was interested in.
Maybe this is a bit complicated to implement, but I think it would certainly be a great improvement. Another application would be: a quicker way to find an article belonging to a certain section whose subject is not listed in the table of contents. The search engine of the gazette is only available online.
Thanks for the marvelous job your doing with the gazette:
Sean Mota
(This is a good suggestion and one I have gotten before. It is actually on my list of things to do. I'll try to find time for it sooner rather than later. --Editor)
Date: Tue, 8 Sep 1998 23:43:49 -0400
From: "Michael Longval",
Subject: Linux installation not easy.
As a computer user and technology observer for the past 20 years I fear the domination of the tech sector by one very large corporation aka Microsoft. We are alas left at the mercy of a company not known for the quality of it's products, but rather for the intensity of it's marketing of it's products.
Windows 98 works ok for me, but I'm frustrated by it's instability.
I have installed Red Hat 5.0 on my IBM ThinkPad 380, but can't get the X windows part up and running. I'm left with the shell only prompt.
I have looked at the manuals and checked the newsgroups, the web sites but still can't get the X windows parts up and running. I'm not a tech dummy. I've played with complicated systems before. Understand C, Rexx, Pascal, Delphi, and others.
However I'm still stranded. So I still use Windows 98...
The day I can easily boot up Linux to a STANDARD GUI DESKTOP is the day I'll start thinking about switching. Unfortunately for me that day has not arrived yet.
Michael J. Longval M.D.
Date: Tue, 8 Sep 1998 23:33:36 -0400
From: "Chris Bruner",
Subject: support problems
I purchased the Red Hat brand of Linux chiefly because of the 90 day installation support. In a nutshell, at first I'm told some very basic things which I had already tried, then when I ask if an alternative was a viable solution (recompiling the kernel with PnP built in) I was told that my problem was no longer covered under the installation support. I still don't have sound and as for my other open tickets, only one other was responded to (after weeks) and I haven't heard back on the rest. So I'm not on the Internet yet, I have no sound yet, and I'll never recommend Red Hat to anyone because of their support.
Chris Bruner
Date: Tue, 01 Sep 1998 21:08:59 +0000
From: Trey,
Subject: Linux Desktop
I was flipping through the recent Linux Gazette and noted the article about Linux on the desktop. I thought perhaps I should chime in as I have had a purely Linux system sitting upon my desk now for well over a year and would not have it any other way.
Ashton Trey Belew
Date: Tue, 15 Sep 1998 16:01:11 +0100
From: Peter Houppermans,
Subject: Linux acceptance
I've seen quite a number of letters stating that to improve Linux acceptance it should have an easier to use GUI et all.
I'm not sure I'd agree entirely with this. The point where Linux is making inroads is not in the desktop arena. I'll most likely attract lots of flames for this, but Microsoft has done a reasonable job in making their desktop products useful, and easy to use. How many people need the manual with Word or Excel ?
Sure, it crashes frequently for some people, but for a large number of users it doesn't matter because they shut down the machine at the end of the day, conveniently saving slow memory leaks from exposure. And I have a W95 system that tends to get rebooted every two weeks, just to clear it up. No need to do it more often. So that community has zero interest in an alternative, other than for cost saving reasons. To convince those people you'll have to give them something that is nearly as easy to use, at a lower cost -and that includes staff costs for setting it up. What is needed here is a way of actually restricting the richness of the XWindows interface so users don't get the chance to shoot themselves in both feet and reduce support needs. I'm sure it is possible, but there has been no concise effort towards this idea. KDA, Gnome and Enlightenment are extremely impressive efforts, but they enrich the setup, not lock it down for Johnny EndUser who just wants to run his word processor. Give them a command line and they'll panic ;-(...
Where Linux *IS* making a difference is in the server arena. If a desktop crashes it affects one (1) user, if a server crashes it takes everyone down who's connected. Instantly, the impact on productivity is amplified. What creates reluctance to accept Linux as an alternative is the lack of people to shout at if it goes wrong. Also, there are only now a few companies that offer a Service Level Agreement on support for Linux, and lack of support is a very nervous thing if you run mission critical applications. Yes, I agree with many that the main issue is not support, but not having a need for it, but one has to deal with disaster recovery as well, and overall system management. Only now CA has brought out some management modules for Linux (to make Linux systems visible in Unicenter TNG). And I'm not aware of any HP OpenView MIBs for Linux (if there are I'd be very happy to hear of them and I'd like to see both of these packages themselves run on Linux).
Any company that wants to use Linux wholesale will want to manage it, and until hard commercial tools are there this won't happen unless through the back door.
I would be very happy to see an alternative to NT, if only just for keeping MS on their toes. Linux is very hard on its way to become that alternative, but I'm not sure it is entirely there yet. Support from SUN, Oracle, CA and Netscape makes a difference, but it takes more than that to change a corporate strategy. Case studies where Linux is shown to be a viable Enterprise OS with the associated cost savings, improved reliability, manageability and all that goes with being a grown up OS will do more to convince the board than any other well-meant effort.
Just an observation....
For the record:
I myself use Red Hat Linux 5.1 on most of my home systems (except the one W95 box) and on my Toshiba 480CDT (HOWTO web page appearing shortly), and I've used virtually every version of Windows and DOS since DoubleDOS appeared, and all versions of OS/2 since v2. I've been a Linux user for about 6 years, having had no previous exposure to Real Operating Systems <g>. So I'm not an expert, but I'm not entirely clueless either ;-).
Regards, Peter
Date: Wed, 23 Sep 1998 15:31:40 +0200
From: Ian Carr-de Avelon,
Subject: GUI and novices
This is my response to the letters by James Mitchell (Sep 98) and Antony Chesser (Aug 98). Well designed GUI's speed up the learning process because the user can see that there is a possibility. The user may have no idea what the icon of scissors will do, or even recognize that they are scissors, but if there is a button you learn very quickly you can click on it with the mouse and so lets give it a try. That simple peace of knowledge, that buttons can be pressed, will get you quite a way in a GUI. Knowing that you could use "<esc>d5" in vi will not take you nearly as far. Not only novices benefit, also it is a major help to users who work with a program only occasionally. Finding the button which does "that" is easier than remembering a sequence of keys. Microsoft have added standardization. You click on the little x button and the program stops. A command line program could require you to type: end, quit, exit, bye... etc. Even with a foreign language version of Windows you can normally manage a few things, just because the layout is standard. I run a local ISP so I have used Linux daily for over 2 years, almost exclusively in command line mode. I understand its strengths but I can still recognize the problems which other users would have. Possibly that is because I visit clients to help them with their problems, or maybe it is because I worked as a teacher and later as a designer of educational material. At any rate I can see that Linux is not yet a real option for most users and anyone who cannot should offer a few hours of their time to support new users, the revelation would come quite soon.
This is a truth which I find quite painful to take, because there is nothing about the Linux OS which makes it so. The installation does not have to end with # prompt and Linux has not just one but several GUIs available any of which could be used in a consistent way by well designed programs. Although Microsoft have done more work in that respect, they are as far from being the best that their could ever be as their OS is in other ways. Many people who really want to see Linux being more widely adopted feel that this does not matter. Linux is being adopted for server applications and they hope that that will be enough to get people to make the effort to learn how to use it. My feeling is that most users choose NT because it looks like 95 which they have on their work station. Linux needs to selectable for basic office tasks before it will be widely accepted. Maybe Linux Gazette should run a competition for a best GPL suit for novice users:
A small novice package which could be included in most distributions and start up at boot time or alternatively with a standard command like "desktop". Would make it much easier to say to clients who's win95 has died again "Why don't you let me install Linux for you?" Yours Ian
Date: Wed, 23 Sep 1998 14:24:23 +0200
From: Stefan Zandburg,
Subject: text browsers
Ijust have read some of the Linux Gazette. It contains quite a bunch of useful information. On many pages some of that information is for me difficult or impossible to read.
The reason is that <B> bold text </B> is hardly visible in the browser i use. (lynx 2.7.2 beta, alternative, an even older version) The machine that acts as a terminal to the Novell Server only has a monochrome screen. As you may have concluded from stating the Server, it is beyond my abilities as user to install a graphical browser. I wish to read the Linux Gazette though and cannot do that on my home computer because i do not have an internet connection there.
If you'd use other tags like the Italic tags <I>.. </I> or the Font tags <Font size+1>...</Font size> people like me would be able to read your Gazette. The browser ignores unknown tags but it does support the bold tags and displays it awkward.
Here at our institute nearly 5000 students use the same browser to regularly visit the web. Although we all wouldd prefer using a graphical browser that is not likely to happen within reasonable time. Using the other tags in the future however would be only a small effort for you.
Stefan Zandburg
I sympathize with you, but bold and italic are used for two different purposes. If I always used italics, the difference in emphasis would not be apparent. There is also the problem that most articles come to me already tagged and I don't have the time to change them. I will think about this though and see what I can come up with. I mainly use bold for the subject lines of letters. That I can change easily. Consider it done. --Editor
Date: Mon, 21 Sep 1998 14:34:18 EDT
From:
Subject: Linux is the #1 OS on the Internet
Many of you may have seen these results, but I hadn't seen anything on any of these lists, so here it is:
Based on surveys of 810,000 European Internet servers, the Linux Operating System is the most used OS on the Internet. Three different categories were polled, web servers, FTP servers, and news servers. Not only was Linux number one in each category, but there wasn't even a consistent number two. Linux's market share went from 25.7% for news servers, to 26.9% for web servers, to 33.7% for FTP servers. In order to get a number two position in web servers and FTP servers, Windows 95/98 was lumped together with Windows NT. They aren't the same system. For news servers, Solaris came in second.
To get to the survey details, go to:
http://www.hzo.cubenet.de/ioscount/
Date: Fri, 25 Sep 1998 08:48:10 -0500 (CDT)
From:
Subject: WilberWorks
I ordered the GIMP CD from WilberWorks quitre some time ago and have heard nothing. E-mails have been ignored; I am getting ready to actually call them I wonder if others have had trouble with them? At their web site their FAQ includes several questions from people wondering where their CDs are--but those are fairly old, so either people wised up (except me) or they improved.
Thanks--
Jim Clark [email protected]
Date: Mon, 21 Sep 1998 22:06:58 -0700
From: Ken Linder,
Subject: YMGP (Yet More Good Press)
More mainstream press! And in a rather high-brow weekly CEO/CIO type periodical. The September 21st, 1998 issue of Computer World has it on page 34 in their "Computer World Quick Study" column. Very well done, IMPO. Also references Red Hat and Linux Journal.
With it in this paper, hopefully, the CIOs and CEOs will start talking with their technical people, trying to find out more about this OS. Normaly when I see the CEO heading twards me, I try to find somewhere to hide, but if he wants to ask about Linux, hey... I can talk to him as long as he likes!
Later...
Ken
Date: Tue, 29 Sep 1998 13:31:01 -0400
From: David Nelson,
Subject: In Praise of Wabi
With Wabi selling for $45 or less, I wanted to share my satisfaction with this product in case anyone else is interested. I have been running WIN 3.1 and Wabi on top of Linux for about five months with very good results. It lets me use several Win 3.1 (16 bit) applications, primarily Quicken 4 and MS Office 4.2, that previously forced rebooting into DOS. I am running a 200 MHz Pentium with 32M of memory. No problems with memory (about 13MB to run Quicken, WIN 3.1, and Wabi) and only a small speed hit (20-30%) on calculation intensive operations. I use the printer, floppy, and modem under Wabi, but no sound, as advertised. Wabi has limited printer drivers, but if your Linux is set up to print Postscript, using Ghostscript drivers for your printer, it will work fine. My Powerpoint viewgraphs, including art, look identical under Wabi, printing to Postscript and under Win95, printing directly to PCL. The Windows clipboard works as expected, and in addition I can cut and paste between Windows and X Window applications.
Wabi accesses my application and data files in the DOS/Win95 partition, so I could convert transparently from DOS over to Wabi -- a nice trick for Wabi to look through Linux back to the DOS file system. Though I haven't tried it, I expect I could see files on my other networked computers using SAMBA. My total extra disk space is 12MB for Wabi, and 24MB for WIN 3.1 files. You need a copy of WIN 3.1, WIN 3.11, or WIN for Workgroups in addition to Wabi. WIN95 won't work. As a bonus, you can run Windows applications remotely using an X-terminal, such as another Linux box. This is like Citrix Winframe, but a heck of a lot cheaper.
Is it a perfect fit? Not quite. I have a formatting problem printing checks from Quicken on my ancient FX80 dot matrix printer, and there are a few quirks such as a disappearing cursor and "bleed through" from background windows in Quicken. But I consider these minor nuisances that don't reduce utility. Sure, I can't use 32 bit Win apps, and some might say that Quicken 4 and MS Office 4.2 are ancient. But I have Quicken 96, 97, and 98 as well as Office 97 sitting on my shelf. I tried them and for my needs there was no more useful functionality, just more bloat and glitz. You make your own decision; I found $45 a good deal.
David B. Nelson
![[ TABLE OF CONTENTS ]](../gx/indexnew.gif)
![[ FRONT PAGE ]](../gx/homenew.gif)
More 2¢ Tips!
Newbie Help Redux (1)Quick answers to get you started:
1. I have grown fat and lazy with Win 98 and find myself looking for "Display Properties" and such. I'm very familiar with C and such and am not afraid of hacking scripts or the like, but my problem is thus: Where is a (succinct) list of what gets run when, from where, and why. I'd love to tweak everything if only I could find it.
A. Take a look at /etc/rc or possibly /etc/rcX.d, where X is 1,2,3, etc. I don't have RH5.1 but I think it uses the System V init system, so these directories should exist. If so, this is where you find the scripts that get run at boot time. For more details, you should look into the "init" tool. I suspsect this is covered in depth in some of the newer Linux system management texts. It's not hard to understand, really. There are different run levels, and scripts for specific run levels get run at start up to get things going and again at shutdown to bring them down again.
2. I have something called an "Ensoniq Audio PCI" sound card with "legacy emulation" I don't even know how to begin to get this thing working. What are the first steps in enabling hardware?
A. Commercial solution: http://www.4front-tech.com. This is a commercial sound driver but don't fret - it's only $20 and works like a champ right out of the box. I have it and have had zero problems. I've suggested it to a few other folks and they all seemed to like it too. There is a non-commercial version of this same set of drivers available for Linux too. But I punted on it when I heard about the commercial driver.
3. Where do I get information on mounting drives?
A. mount -t fat32 /mount_pt_dir or possibly mount -t vfat /mount_pt_dir. I don't use MS on my box so can't remember which one of these works with FAT32 partitiions but I'm fairly sure one of them does. In any case, other folks are likely to respond with more detailed answers on this one.
4. I think my printer works (at least text does), but how do I print things (man pages)?
A. xman will print the pages as postscript but you need to set up a print spooler using Ghostscript. A print spooler is just a locical printer name that accepts print requests, processes them with some filters and then feeds them to the printer of choice. Ghostscript will translate Postscript input into the printer command language for your printer. I keep forgetting where the Ghostscript FAQ (including download info) is at, but you can find it by searching on Yahoo. That's what I always do.
The hard way to set up printers is to learn about configuring /etc/printcap. However, my RH4.2 system has a fairly decent printer configuration utility so I suspect 5.1 has an even better one. The bad news is I can't remember the program's name (it's in my fvwm2rc at home and I never type it by hand). Check the documentation that came with the CD. I know it's mentioned in there.
Best of luck.
Michael J. Hammel
Re: Help Wanted : newbie (2)From: Dennis Lambert, [email protected]
I have grown fat and lazy with Win 98 and find myself looking for "Display Properties" and such. KDE (http://www.kde.org/) is supposed to be a more integrated desktop environment, and Gnome (http://www.gnome.org/) is coming along. I'm very familiar with C and such and am not afraid of hacking scripts or the like, but my problem is thus: Where is a (succinct) list of what gets run when, from where, and why. I'd love to tweak everything if only I could find it.
Linux is a complex OS, so the list isn't succint. There's a description of the boot process in the System Administrator's Guide. If you're new to Linux, I'd recommend you give the SAG a good browse. There's *lots* of useful information there. You should have an HTML copy installed in /usr/doc/LDP/sag.
The Network Administrator's Guide (/usr/doc/LDP/nag) is also good to have, but the HOWTO's are better if you just need "cookbook" style docs. The HOWTO's are in /usr/doc/HOWTO. You should fire up Midnight Commander (mc) from the command line and take a look around /usr/doc.
I have something called an "Ensoniq Audio PCI" sound card with "legacy emulation" I don't even know how to begin to get this thing working. What are the first steps in enabling hardware?
There is a PCI-HOWTO and a Sound-HOWTO.
Where do I get information on mounting drives (FAT 32 especially)
In the Config-HOWTO or the archives of the Red Hat mailing lists.
I think my printer works (at least text does), but how do I print things (man pages)
Text and postscript are easy. Fortunately most things are convertable to postscript. In this case use:
The Mailbag!
man -t CommandOrSubject | lpr
This is covered in the man page.
If you haven't joined any of the Red Hat mailing lists, you might consider doing so. Be warned though; they tend to be busy lists (http://www.redhat.com/support/).
Welcome to Linux...
Tony
Clearing the Screen (1)I have seen a lot of hints for restoring a trashed screen or window, but none of them mention the reset and clear commands. Are these commands deprecated, do they have unwanted side effects, or are they ineffective in certain situations?
When I have cat'ed an executable, I usually just type: reset <ENTER> and let the garbage scroll off the screen.
If, for some reason, I find the garbage characters annoying, I follow this command by typing: clear <ENTER>
Anthony Christopher
Re: simultaneous versions of kernelsJust my 0.02 Euro:
Most of the installation problems are caused by interaction with the linux distribution's default installation method. You can easily work around this by simply not installing your compiled kernel. Lilo and insmod support loading directly from the compilation directory.
Just unpack your kernel in an arbitrary directory, say /home/kernel/linux-test, apply any patches and compile: make [x|menu|old]config; make dep; make zImage modules. But do neither make install nor make modules_install.
Then add something like this to your /etc/lilo.conf:
# Linux bootable partition config begins # test new (not installed) kernel just compiled in directory # /home/kernel/linux-test. image = /home/kernel/linux-test/arch/i386/boot/zImage root = /dev/hda3 label = test append= " MODPATH=/home/kernel/linux-test/modules/ " # Linux bootable partition config ends #and run lilo whenever you have recompiled your kernel image.
When booting, choose "test" from the lilo prompt. The kernel will pass MODPATH to the environment of init and any startup routines that insmod's kernel modules will fetch them automatically from the kernel compilation tree.
(If you additionally want to insmod some modules by hand from a root shell, MODPATH might be unset. But scripts can still extract that information from /proc/cmdline).
Henner
Question about your Linux Gazette postIn a previous message, [email protected] says: is there an url for this program?
No, not that I know of. A couple of people have asked this. It's part of the core set of files in my Red Hat 4.2 distribution. Units has been around so long, and is available on so many different Unix platforms, that I suspect most distributions have a copy of it somewhere. On my RH4.2 it's under /usr/bin.
mjhammel(ttyp2)$ type units
units is /usr/bin/units
mjhammel(ttyp0)$ units
501 units, 41 prefixes
You have: 3 miles
You want: kilometers
* 4.828032
/ 0.20712373
Michael J. Hammel
COBOL Compilers for LinuxConcerning the following, recently posted in Linux Gazette:
I have a friend who is doing a refresher course in Cobol in a Unix environment. I have suggested that she run Linux, and pick up a cheap / shareware copy of a Cobol compiler for Linux from somewhere. Knowing absolutely nothing about either Linux or Cobol, am I dreaming, or is there a realistic alternative to the compilers I have seen retailing for ~$1,500 US? I'd really appreciate any help/advice anyone can offer.
There are several possible COBOL options in the Linux realm; for details see:
http://www.hex.net/~cbbrowne/languages07.html
There's not anything yet that could be considered 100% viable outside of (rather expensive) commercial options; obviously these sorts of things don't happen without there being a population of people who are interested enough to be willing to invest the time necessary to implement something.
Resetting the term (2)You posted a program to reset your console should the text become garbled. I thought I would mention that most distributions, Slackware notably, come with such a program that does this and more.
reset will clear your tty, restore sane tty settings, and perform general tty cleanups. You should find this little utility just about anywhere :)
David
Re: Help Wanted : newbie (3)In anwser to your questions in the September issue of the Linux Gazette:
I recently purchased Red Hat 5.1 and got it running. Evidently I was lucky in that I have a fairly full FAT 32 Win 98 drive and kind of stumbled through the defrag / fips / boot to CD / repartition / full install with LILO process. Everything worked, but I'm a little nonplussed. A few topics I'd absolutely love to get feedback on... Turns out I have a lousy WinModem. I can see the feedback now, (Run it over with your car)
Yep. Buy a *real* modem.
I have grown fat and lazy with Win 98 and find myself looking for "Display Properties" and such. I'm very familiar with C and such and am not afraid of hacking scripts or the like, but my problem is thus: Where is a (succinct) list of what gets run when, from where, and why. I'd love to tweak everything if only I could find it.
Daemons, boot time initialization: see the man page for `init'. There'll be an assortiment of scripts in /etc/rc.d or /etc/init.d and /etc/rcX.d (where X = 0 to 6) that do your system's boot-time setup.
For X, especially XFree86, you can fiddle with the XF86Config file, which should reside somewhere in /etc. Or if you have an X server running you can use `xvidtune'. The programs and window-manager started by the X server are usually in a file called xinitrc or xsession.
I have something called an "Ensoniq Audio PCI" sound card with "legacy emulation" I don't even know how to begin to get this thing working. What are the first steps in enabling hardware?
You'll probably need to compile a new kernel. The sound driver that comes with the kernel supports this card. install your distribution's kernel source package, cd to /usr/src/linux and read the README.
Where do I get information on mounting drives (FAT 32 especially)
Read the manual for `mount' and `umount'. Make sure you have a kernel with (V)FAT support compiled in.
I think my printer works (at least text does), but how do I print things (man pages)
Use the lpr program. It is a print spooler. You might want to fiddle with /etc/printcap to enable your printer to print PostScript (via GhostScript).
I'm not an idiot, not even a "dummy", but what is a good book to answer the basic questions? I have "Linux in a Nutshell" and it has a very good command reference and a few other things, but doesn't help in tweaking things.
I haven't read many books on Linux, just *lots* of manpages and HOWTO's (in /usr/doc/HOWTO). Ask around in linux newsgroups.
I don't really expect anyone to answer all of these concerns, but any little help would be greatly appreciated.
Hope this helps... :-)
Roland
2c tip -- more fun with pipesAfter reading the "Un-tar as you download" 2-cent tip from [email protected] in issue 32, I thought you might like this, too.
Say you have a program with a large initial startup time. After that, the program reads a line from a file, processes it, reads the next line, processes it, etc, until EOF. You would like to process a single line of data without suffering through the initial startup each time. Try this:
mkfifo input_fifo
rm input_file
touch input_file
tail -f input_file >> input_fifo &
long_program input_fifo &
When you want to feed it some data, say
echo data1 data2 data3 >> input_file
The tail will wake up, read the line, output it to the fifo (aka "named pipe"), the program will wake up, read the data from the pipe, process it, and go back to sleep.
(You only have to do the mkfifo once; after that, it sticks around. On some systems (e.g. my Sun at work, where I came up with this), instead of mkfifo filename, use mknod filename p".)
To shut things down, kill the tail. The program will get an EOF condition, and shut down normally.
Of course, a better solution might be to rewrite the program to read from stdin, and then say
tail -f input_file | long_program -
but you can't always do that. Also, neither of these ideas will work if the program reads the whole file, and then processes each line from an internal list.
-- Larry Clapp
2 cents tip: Un-tar as you downloadlynx -source http://www.url.dum/file.tar.gz | tee file.tar.gz | tar zxm lynx -source ftp://ftp.url.dum/file.tar.bz2 | tee file.tar.bz2 | bunzip2 - | tar xm
Ben
Re: Help Wanted: Looking for an Xwin Server software that runs under win95/ntFrom: Mark Inder, [email protected]
We use a Red Hat 4.2 machine in our office as a communications server. This is running well with the facility oftelnet connections for maintenance, diald for PPP dial up - internet and email, and uucp for incoming mail. I would like to run an X server on my windows PC to be able to use X client software on the Linux PC over the local Ethernet. Does anyone know of a shareware for freeware version which is available.
Try the list at http://www.rahul.net/kenton/xsites.html#XMicrosoft
this one is free for example http://www.microimages.com/www/html/freestuf/mix/
Caolan
Re: Help wanted for a (Cheap) COBOL combiler for LinuxFrom: Andrew Gates, [email protected]
I have a friend who is doing a refresher course in Cobol in a Unix environment. I have suggested that she run Linux, and pick up a cheap / shareware copy of a Cobol compiler for Linux from somewhere. Knowing absolutely nothing about either Linux or Cobol, am I dreaming, or is there a realistic alternative to the compilers I have seen retailing for $1,500 US? I'd really appreciate any help/advice anyone can offer.
I haven't ever used Cobol, but at http://www.deskware.com/cobol/cobol.htm, there's a Cobol for Linux under development for download (for free I believe). Might be good to check it out, and to find out if it's of any use yet.
Caolan
Re: Clearing the Screen (3)In the September issue you described some C code that can clear the screen when it gets screwed up from binary dumps to the terminal. There is a much easier way and it all it requires is the keyboard ;) Simply type "echo control-v escape-c" where and hit enter. The "control-v" allows you to type in the "escape-c" literally.
This has worked much better for me then some other methods such as "reset" which comes with your favorite Linux distribution but like a compiler it isn't always there. This key sequence is *always* available on an ANSI terminal.
Mark Ramos
Unix TipAs an addendum to Allan Peda's Tip in Linux Gazette issue 32, here is a quick tip that applies to most DEC emulators (vtXXX):
echo ^V^O
That's echo, control-V, control-O. The control-V portion escapes the control-O (terminal reset) from your shell. The echo just puts the control-O right back to your terminal emulator/dumb terminal (works great on true DEC terms too! :)
This works for most Unix flavors. No code. Easy to remember.
Ian Blenke
rc.local TipI've been reading the Linux Gazette for a couple of months now and I think it's great, especially the tips.
Here's one for you to consider that was inspired by Dennis Lambert's "Help Wanted" letter in issue #32. I hope it doesn't duplicate something you've already published.
To those of us used to the warm, fuzzy DOS world of CONFIG.SYS and AUTOEXEC.BAT, the complexities of the /etc/rc.d startup heirarchy can be nothing short of intimidating. Well, I decided to make it a little less so. I started by putting these lines at the top of /etc/rc.d/rc.local:
echo "===============================================" echo " " echo "Now running rc.local" echo " " echo "==============================================="Now, when I start up Linux I can tell just when my local configuration starts to run, and if I'm having problems I can see whether they happen before or after rc.local starts. You can learn other things, too -- I learned that rc.sysinit gets run on startup and shutdown!
Unfortunately, especially if you have a fast system, you can miss error messages as they scroll by and dmesg doesn't always echo the information you need to solve a problem. I was seeing error messages in rc.local, but I couldn't tell what they were because they went by too fast. So, I wrote a Perl one-liner:
perl -e "print 'Press ENTER to continue: '; $x = <:STDIN>;"This prints a prompt, then waits for you to press ENTER before it continues. (Yes, there's probably an easier way to do this with bash or some utility, but I already know Perl and I'm still learning bash. [grin]) By putting this at the bottom of rc.sysinit I made the boot-up sequence stop so I could see the error message, and of course once I saw it I knew exactly how to fix it. I comment out the line unless I need it, of course -- if everything is working right I want Linux to take me straight to the login prompt!
Here's hoping this helps someone.
Creede Lambard
Yet another method of resetting scrambled terminal after dumping binary data.Perhaps this is the simplist solution:
echo '\017'
that's it.
Sang Woo Kang
Rick's quick and dirty screen-saverHere's a shell script which cycles through jpgs:
#!/bin/sh
# showjpg Rick's quick and dirty screen saver.
# Run from an xterm. Controll 'C' should get you out. Or run in
# background with '&' and use kill.
# forever
while [ 1 ]; do
# The path to your jpgs
for file in /usr/local/images/jpg/*.jpg
do
xsetbg $file
sleep 20
done
done
xsetbg is from the xloadimage package. It's the same as:
xloadimage -onroot -quietSleep is in seconds. Use convert from the ImageMagick package to convert .gif or .bmp to .jpg.
Rick
MS Word & NetscapeI wish to contribute 2 cents story.
One-click view of MSWord files in Netscape.
There is a sad fact, that some people use MSWord to exchange documents. When one one gets such file in a mail on Linux (s)he can use MSWordView, but this requires:
Save file Convert from .doc to .html Start Netscape to view itThis 2 cents tip is about how to reconfigure netscape in order to view MSWord documents in one click.
To do this:
application/msword; ns="%s"\; nf="${ns}".html\; mswordview "${ns}" >"${nf}"\;
netscape -remote 'openURL(file:'"${nf}"')' \; sleep 2 \; rm "${nf}"
Pulling Files from NTNothing groundbreaking here but, being a newbie to Linux and Samba I was having a difficult time getting Samba set up and needed to get some large files from an NT server to a Linux machine. I do not have any NFS programs for NT but do have a Web/FTP server running on NT so my temporary but quick solution was to put the files I needed into my NT server's FTP directory and download them from there.
Michael Burns
Re: The wisdom of US West...Michael J. Hammel wrote: I haven't checked, but doesn't IPv6 have 6 dot-values? And are they larger than 8 bit values? Just curious. I haven't heard much about IPv6 in awhile and wondered how we haven't run out of IP space yet without it.
From: Jay Kominek,
IPv6 addresses take the form of 'FEDC:BA98:7654:3210:FEDC:BA98:7654:3210' 8 16-bit hexadecimal chunks. All kinds of fun. Luckily, if you have a string of zeros in your address, you can do something like 1080::8:800:200C:417A
To save yourself some typing.
I hope I'm not running some place's DNS when IPv6 becomes popularized.
Relevent RFCs:
RE: Clearing the Screen (4)From: Allan Peda, [email protected]
A few days ago a classmate "accidentally" cat'ed a file to the screen. He asked asked me what he could do to reset his confused vt100, as clear wasn't sufficient.
reset works very well for this. The command reset will effectively reset the screen by sending it the proper escape sequence. since reset looks up the escape sequence from the terminfo library so it works on just about any terminal. If this fails, sometimes a
$ stty sanewill do the trick.
Re: Keeping track of your config filesYour idea for keeping track of those files by linking them to a central directory is good.
Another idea I am using frequently is keeping track of the modifications by either employing SCCS or RCS (or whatever derived utility available).
Combining both ideas means for SCCS based systems: Use e.g.
$ cd /
$ sccs -d/root/SCCS create etc/inittab
if you share a lot of these files across several systems, but there are some files that may differ you probably like to type
$ sccs -d/root/SCCS -p`hostname` create etc/lilo.conf
Which results in the following tree:
/root
|-/SCCS
| |-etc
| | |-s.inittab
| | |-apollon
| | | |-s.lilo.conf
| | |-jupiter
| | | |-s.lilo.conf
...
For daily use I recommend to keep all the files 'checked-out', i.e. 'sccs edit' always after 'sccs create' and otherwise 'sccs deledit'. The above commands should also be abbreviated by aliases.
For the RCS used admins I recommend 'cvs', but this means a bit more work ....
Andreas
 |
Contents: |
November Linux JournalThe November issue of Linux Journal will be hitting the newsstands October 11. The focus of this issue is Web Programming and we have articles on FastCGI, HTMLgen, XML, SGML and Python, as well as an interview with Guido van Rossum, the creator of Python. Check out the Table of Contents at http://www.linuxjournal.com/issue55/index.html. To subscribe to Linux Journal, go to http://www.linuxjournal.com/ljsubsorder.html.
Links2Go Key Resource AwardDate: Wed, 22 Jul 1998 18:38:48 -0400
Congratulations! Your page: http://www.linuxgazette.com/ has been selected to receive a Links2Go Key Resource award in the Linux topic.
The Links2Go Key Resource award is both exclusive and objective. Fewer than one page in one thousand will ever be selected for inclusion. Further, unlike most awards that rely on the subjective opinion of "experts," many of whom have only looked at tens or hundreds of thousands of pages in bestowing their awards, the Links2Go Key Resource award is completely objective and is based on an analysis of millions of web pages. During the course of our analysis, we identify which links are most representative of each of the thousands of topics in Links2Go, based on how actual page authors, like yourself, index and organize links on their pages.
For more information:
Links2Go Awards,
X11.ORG goes publicDate: Thu, 10 Sep 1998 00:31:27 -0400 (EDT)
One of the main purposes of X11.ORG is to provide the X community with up-to-date information regarding "anything and everything X". By making this information easily available, you don't have to work quite as hard to keep up with the fast-moving pace of X developments. As it was imagined in the development process, we will attempt to be a slashdot.org of sorts, for the X community, focusing on those topics directly or closely related to X. X11.org plans to cover the setup and configuration information for the majority of WindowManagers, Desktop Environments (eg. CDE, GNOME, KDE), and X Servers.
http://www.X11.org/
For more information:
Voltaire,
7th Python ConferenceDate: Wed, 16 Sep 1998 17:18:14 -0400 (EDT)
Call for Participation and Advance Program, 7th International Python Conference:
http://www.foretec.com/python/workshops/1998-11/
South Shore Harbour Resort
Houston, Texas
November 10-13, 1998
Sponsored by CNRI and the PSA
The Python Conference brings together a broad range of users, vendors, researchers, and developers from the Python community. The conference is the premier opportunity to meet other Python programmers, share information, and learn about the latest happenings -- including an update on the future of Python from its creator, Guido van Rossum.
The program also includes a day of tutorials, two days of papers and invited talks, and Developers' Day. The conference program has been expanded this year to include a session for demos and posters to highlight work that is more interesting to see and interact with.
For registration information, visit:
http://www.foretec.com/python/workshops/1998-11/registration.html
INVITED SPEAKERS
Eric Raymond, "Homesteading the Noosphere." Custom, ego, and property in the open source community.
David Beazley, "Commodity Supercomputing with Python." Python on supercomputing systems, and its role in the 1998 Gordon Bell Prize Competition, where a Python-driven application achieved 10 Gflops sustained performance on a Linux cluster.
Jim Hugunin, "JPython." Recent and coming events in the happy integration of Python and Java.
Guido van Rossum, "Python -- the next seven years." Recent and coming events in the development of the Python langauge.
For more information:
Jeremy Hylton,
LISA '98, Systems Administration ConferenceDate: Mon, 14 Sep 1998 16:04:13 -0800
The Immediately Practical is the Emphasis at Largest Conference Exclusively for System Administrators
LISA '98, the 12th Systems Administration Conference, is co-sponsored by SAGE, the premier professional society for system administrators, and the USENIX Association. It will take place in Boston at the Marriott Copley Place Hotel, December 6-11, 1998. The largest conference exclusively for system administrators, LISA is expected to attract over 2000 attendees.
Full Technical Program: http://www.usenix.org/events/lisa98/
For more information:
http://www.usenix.org/ Dona Ternai,
Linux LinksThe Linux Software Encyclopedia: http://stommel.tamu.edu/~baum/linuxlist/linuxlist/linuxlist.html
COBOL Center: http://www.infogoal.com/cbd/cbdhome.htm
Deskware COBOL: http://www.deskware.com/cobol/cobol.htm
Collection of Free Resources: http://members.tripod.com/~net_tools/index.html
Linux Preview (Spanish): http://linux.ncc.org.ve
Crystal Space 3D Engine: http://crystal.linuxgames.com
GNOME FAQ: http://www.mindspring.com./~tlewis/gnome/faq/v1.0/FAQ.html
Linux Links: http://www.linuxlinks.com/
DOSEMU.ORG: http://www.dosemu.org/
Spanish Linux Index: http://www.croftj.net/~barreiro/public/indice.html
Linux soundapps Webpage: http://www.bright.net/~dlphilp/linux_soundapps.html
SciTech Display Doctor for Linux: http://www.scitechsoft.com/sdd_linux.html
K-12 and LinuxDate: Tue, 8 Sep 1998 08:10:42 GMT
A mailing list has been formed where people with Linux expertise can support K-12 people who are trying to use Linux in schools. To join, send e-mail to and in the body of the letter, enter: subscribe lxk12
For more information: Randy Wright,
Red Hat Hands Applixware back to Applix, Inc.Date: Thu, 17 Sep 1998 12:03:00 GMT
September 14, 1998--In order to focus exclusively on developing and marketing the Open Source Red Hat Linux operating system, Red Hat Software, Inc. and Applix Inc. today announced that Applix Inc will have all future responsibility for the Applixware Office Suite, including Sales, Marketing, Product Support, and Quality Assurance.
Applixware products previously purchased directly from Red Hat Software will still receive the full technical assistance and support of Red Hat Software.
The announcement of the new relationship coincides with the release of Applixware 4.4.1 for Linux. This update of Applixware features all the standard components of the Applixware Office Suite, as well as Applix Data, a new module offering point and click access to information stored in relational databases, and Applix Builder, Applix's object-oriented, visual, rapid application development tool.
The Applixware 4.4.1 Office Suite is available directly from Applix, Inc. for $99. For those wishing to upgrade to Applixware 4.4.1, Applix is offering a $79 upgrade. For more information, please see
For more information: http://www.applix.com/
Intel, Netscape invest in LinuxDate: Tue, 29 Sep 1998 11:43:45 -0700
Red Hat Software has announced that Intel, Netscape and two VC firms are taking equity positions in the company which will enable it to create the Enterprise Computing Division. This division will ready Linux for enterprise-wide applications, enabling Linux, the most open, robust and carefully scrutinized operating system in the world, to tackle the likes of Windows NT.
For more information:
Full Press Release
Red Hat News FlashDate: Mon, 28 Sep 1998 09:30:03 -0700 (PDT)
It has recently come to the attention of Red Hat Software that there are significant security holes in CDE. All users are affected, both those who purchased CDE Client and those who purchased CDE Developer that runs on Red Hat Linux 4.0 up to 5.1.
For more information:
Full Press Release
Canadian National Installfest a SuccessDate: Sun, 27 Sep 1998 19:58:06 PDT
The Installfest referred to in last months News Bytes has come off an outstanding success! Details at http://www.linux.ca/installfest.html
A world-wide installfest in the offing?
For more information:
Dave Stevens,
Linux/Personal Productivity ToolsLOS ALTOS HILLS, CA (Sept. 8, 1998) -- Personal Productivity Tools, Inc. (PPT) today announced that version 3.0 of its EtherPage (tm) client/server-to-pager messaging system is now running under Linux, the UNIX clone operating system.
EtherPage delivers messages rapidly and efficiently from computer networks to wireless devices, including alphanumeric and 2-way pagers and digital cellular phones. In addition to Linux, EtherPage now runs under a broad range of operating systems including Windows NT and UNIX.
For more information:
Personal Productivity Tools, Inc., http://www.ppt.com/
LinkScan 5.0 - Breakthroughs in Performance, Scalability & WorkflowSan Jose, CA, Sept. 10, 1998. Electronic Software Publishing Corporation (Elsop) released LinkScan 5.0 today. Major improvements have been made to LinkScan 5.0 to make it serve the needs of workgroups throughout the enterprise and facilitate the workflow between content managers, developers and systems administrators. These improvements are the result of radical design changes that make version 5.0 essentially a new product compared to earlier versions. This effort was energized by the needs of organizations with very large intranet websites and public websites.
LinkScan operates on all Unix Servers (including AIX, BSD, Digital Unix, HP/UX, IRIX, Linux, and SunOS/Solaris flavors) and Windows NT 5.0 servers with Perl 5. Free fully functional evaluation copies of LinkScan 5.0 may be downloaded (less than 300 Kbytes) from the company's website at: http://www.elsop.com/
For more information:
Kenneth R. Churilla,
Electronic Software Publishing Corporation
NetBeans Releases Last Beta Version of Java IDE, Free Download ContinuesPrague, Czech Republic, September 14, 1998 - NetBeans, Inc. today announced the release of the Beta 3 version of NetBeans Developer 2.0. It is the last beta prior to the full release, which is due near the beginning of Q4. Beta 3 is available for free download from the NetBeans web site, http://www.netbeans.com.
NetBeans IDE is a full-featured Java IDE based completely on Swing/JFC. NetBeans is both written in Java and it generates Java code. It is an object oriented, visual programming environment based on JavaBeans components without relying on any third-party components. The IDE is easily extensible, and it runs on any platform that supports JDK 1.1.x, including Win95/98/NT, Apple Mac, Linux, OS/2, Solaris, HP-UX, Irix, and others. Since the June release of Beta 1, over 18,000 new registered users have downloaded the tool.
For more information:
NetBeans, Inc., http://www.netbeans.com,
Product Overview, http://www.netbeans.com/overview.html
NetBeans Bundles Cloudscape with Leading Programming EnvironmentOakland, CA and Prague, Czech Republic, September 21, 1998-NetBeans, Inc. and Cloudscape(TM) Inc. announced today that NetBeans, Inc. will bundle Cloudscape's embeddable Java-based object relational database with upcoming releases of the NetBeans IDE. Founded on the principle of Java innovation, NetBeans is the first company to offer an all-Java IDE based on Swing/JFC. Cloudscape offers the industry's first embeddable Java database, designed to be invisibly embedded within applications as a local data manager.
The Cloudscape database will be bundled with NetBeans Developer 2.0, allowing users of NetBeans Developer 2.0 to create Java applications that integrate a fully functional, yet lightweight object-relational database manager. The integrated product is expected to be available in November 1998. Cloudscape ships the only 100% Pure Java(TM) SQL database manager designed to be invisibly embedded within applications as a local data manager.
For more information:
NetBeans, Inc., http://www.netbeans.com,
http://www.netbeans.com, write to [email protected], or call 011 4202 8300 7322. Cloudscape, Inc. http://www.cloudscape.com/,
Prolifics to be launched for Linux!Mon, 21 Sep 1998 00:34:30 +0200
Based upon market interest and customer feedback, Prolifics has decided to offer a version of Prolifics on Linux. Linux offers the development community a strong platform choice at very modest prices. We feel that Prolifics, based on industry standards such as COM and Java, can offer this community a unique, powerful and flexible tool for building cross-platform database applications. Application Servers for the Web will be provided to process business logic on the Linux servers and deploy the presentation layer on a thin client Web Browser. These applications can be deployed for character-based, GUI and Web environments.
The Linux platform will first be made available with Prolifics 4 Standard. Prolifics 4 Standard is our upcoming 2-tier product release due out 4Q 1998. Look for a customer letter telling you all about it and more this week or next.
For more information:
Prolifics, Devi Gupta,
IGELPalmer, PA - September 7, 1998 - IGEL LLC today announced the availability of Etherminal J, a Thin Client desktop device. The first variant has been exhibited at Thinergy '98, the first global conference on thin-client/server computing held in Orlando, Sept. 1-3, 1998.
Etherminal J, based on IGEL's Flash Linux Technology, is the only thin client device incorporating Netscape Communicator Version 4.05, and a complete set of UNIX connectivity tools, locally in its own Flash Memory. Storing and running these software modules locally keeps network bandwidth requirements at a minimum. IGEL's Flash Linux is a compressed UNIX-compatible, flash memory accessible operating system. It is a POSIX-conform, multi-threading multi user operating system. Based on the popular Linux kernel, it offers the largest number of available device drivers and applications. It supports Internet and Java. IGEL tailored this OS to support a defined Thin Client hardware, and developed a flash memory driver technology to compress this OS, and all accompanying Emulators, X11R6 X-Server, and Thin Clients for multi-user Windows NT, and the Netscape Communicator in 12MB of "Disk-on-Chip" Flash Memory. IGEL's BIOS extensions allow to directly boot this compressed Flash Linux. At run-time needed OS parts, Emulators, Thin Clients, and the Netscape Communicator are decompressed on demand.
For more information:
IGEL*USA, http://www.igelusa.com/
H. Knobloch,
Linux Office Suite 99 from SuSEOAKLAND, Calif.--(BUSINESS WIRE)--Sept. 24, 1998--S.u.S.E., Inc. today announced the release of Linux Office Suite 99 -- a comprehensive software package that combines the latest in Linux technology with some of the most powerful, user-friendly applications on the market.
S.u.S.E.'s Linux Office Suite 99 includes a spreadsheet, word processor, presentation graphics, database, fax program, and many other critical business applications.
Linux Office Suite 99 comes with the latest version of Applixware 4.4.1, which includes Applix Words, Spreadsheets, Graphics, Presents, and HTML Author, as well as Applix Data and Applix Builder. Applixware's latest release delivers a new filtering framework that has been optimized for document interchange with Microsoft Office 97.
In addition, Linux Office Suite 99 integrates Applixware with the powerful ADABAS D 10.0 database system, enabling users to import data from the ADABAS D database into Applix Spreadsheets. Linux Office Suite 99 also contains the KDE and GNOME graphical desktops, S.u.S.E. fax, the personal edition of the backup utility ARKEIA 4.0, the popular GIMP graphics program, and many other features.
Linux Office Suite is compatible with S.u.S.E., Red Hat, Caldera, and other popular versions of Linux. Users who need to install Linux for the first time can do so quickly and easily with the base system of S.u.S.E. Linux 5.3 that is included with the Office Suite.
For more information:
S.u.S.E., http://www.suse.com/
Xtoolwait 1.2Date: Tue, 8 Sep 1998 07:54:58 GMT
One and a half year have gone by without a single bug report, so it's time to release a new version of Xtoolwait.
This utility notably decreases the startup time of your X sessions, provided that you start a number of X clients automatically during the X session startup. Most people, for instance, start X clients like xterm, xclock, xconsole and xosview from their .xinitrc, .openwin-init, .xtoolplaces or .xsession file.
These X clients are started simultaneously (in the background) which puts a high load on the X server and the OS
Xtoolwait solves this problem by starting one X client in the background, waiting until it has mapped a window and then exiting.
Download Xtoolwait from this page
http://www.hacom.nl/~richard/software/xtoolwait.html
For more information:
Richard Huveneers,
Fileman V1.1 - X-window based File ManagerDate: Tue, 8 Sep 1998 08:32:09 GMT
FileMan, a X-window based File Manager offering a large number of features along with great configurability and flexibility is now available as version 1.1.
Version 1.1 offers improved performance and many bug fixes over earlier releases.
Some features are still not fully complete, but it is still very useable and contains enough features to manage a Linux environment.
For more information:
http://www.bongo.demon.co.uk/page6.html
Simon Edwards, FileMan Developer,
ppdd - encrypted filesystem - kernel patch and support progs.Date: Tue, 8 Sep 1998 08:38:12 GMT
ppdd is an advanced encrypted file system for i386 Linux only.
ppdd is used in a similar way to the loop device and offers simplicity and speed plus full strength encryption (128 bit). The design takes into consideration the fact that data on disc has a long lifetime and that an attacker may have the matching plaintext to much of the cyphertext. A combination of master/working pass phrases offers enhanced security for backup copies. Current status is BETA and comments on the implemenation and underlying crypography are most welcome.
It consists of a kernel patch plus support programs and is intended for users with enough knowledge to compile the kernel, setup LILO, partition disks etc. It is not for absolute beginners or "non technical" users yet.
Available from: http://pweb.de.uu.net/flexsys.mtk
Package is ppdd-0.4.tgz, PGP signature is also available from same URL.
For more information:
Allan Latham,
bzip2-0.9.0, program and library for data compressionDate: Tue, 8 Sep 1998 08:47:31 GMT
bzip2-0.9.0 is a high-quality, portable, open-source, lossless data compressor, based on the Burrows-Wheeler transform.
Source code, binaries and further details, are available from
http://www.muraroa.demon.co.uk
and also from the mirror site
http://www.digistar.com/bzip2/index.html
bzip2-0.9.0 is fully compatible with the previous version, bzip2-0.1pl2. In particular, the .bz2 file format is unchanged.
For more information:
Julian Seward, Xterminal 0.4 - Object Oriented User Interface
Date: Tue, 8 Sep 1998 08:45:51 GMT
Xterminal is an Object Oriented User Interface with a client-server architecture. The main purpose is a friendly interface for the UNIX operating systems. It is designed to be used to build text-based applications in C++.
It consists in a complete object oriented library including multiple, resizeable, overlapping windows, pull-down menus, dialog boxes, buttons, scroll bars, input lines, check boxes, radio buttons, etc. Mouse support, advanced object management, events handling, communications between objects are provided, too, together with a complete programmer's manual.
Xterminal is available for download from:
ftp://sunsite.unc.edu/pub/Linux/libs/ui/Xterminal-0.4.tar.gz
http://www.angelfire.com/sc/Xterminal/download.html
For more infomation:
http://www.angelfire.com/sc/Xterminal
Dragos Acostachioaie,
connect v1.0alpha - tool to ease the sharing of a PPP linkDate: Tue, 8 Sep 1998 08:50:39 GMT
Here is the first ALPHA release of connect package (v1.0a)
connect package is a client-server program designed to ease the sharing of a PPP link to the internet over a small network.
connect is a solution. By running a tiny daemon (connectd) that will take care to launch the PPP when asked to and keep it up as long as needed, you can control your link.
As you can talk to the daemon with a command-line or a Java applet, access is easy from a unix host or a browser running on a Win95/NT workstation.
connect can be freely downloaded from its home page, see
http://www.caesium.fr/freeware/connect/index.html
For more information:
Nicolas Chauvat,
PalmPython 0.5.2 - PalmPilot sync/database library for PythonDate: Thu, 10 Sep 1998 10:22:50 GMT
I am pleased to announce version 0.5.2 of PalmPython, a conduit programming kit which enables desktop applications to access PalmPilots and their data. PalmPython is available at the following URL:
http://www.io.com/~rob/cq/palmpython/
PalmPython requires the pilot-link library, which can be found at
ftp://ryeham.ee.ryerson.ca/pub/PalmOS/
For more information: Rob Tillotson,
C++ library wxWindows/Gtk 1.93 and GUI builderDate: Thu, 10 Sep 1998 09:49:21 GMT a new version of the GTK+ port of the cross platform library wxWindows has been released.
To our knowledge, wxWindows is the only cross platform library available for creating native Windows and Unix/GTK+ applications. Although it is not its primary goal, wxWindows should help make the transition from Windows to Linux much smoother, not the least for small companies.
Apart from being platform independent, wxWindows is arguably the most complete free class library around offering features from database connectivity to configuration management to internationalization to a multiple document interface and support for printing using Postscript on Unix. We also provide detailed documentation and a set of sample apps.
http://wesley.informatik.uni-freiburg.de/~wxxt/
The main wxWindows site:
http://web.ukonline.co.uk/julian.smart/wxwin/
wxWindows is free and has been an open source project since long before that term has been trademarked.
For more information:
Robert Roebling,
hm-3.0 - multiplatform curses-based filemanagerDate: Fri, 11 Sep 1998 08:50:49 GMT
hm 3.0 is a multiplatform cursesbased filemanager. Developed, adjusted and matured for 3 years by and for unix system managers. Versatile look from ls-like to ls -ail. All the basics with one keystroke: cd, cat, chgrp, chmod, chown, cp, diff, file, ln, man, mkdir, mv, od, rm, sh, sum, tail -f, vi, wc. Help-facility built in (no man page needed).
http://sunsite.unc.edu/pub/Linux/utils/file/managers/hm-3.0.tar.gz
For more information:
Hans de Hartog,
mswordview 0.4.0 releasedDate: Fri, 11 Sep 1998 12:43:27 GMT
yes the best thing since sliced bread, the ongoing office98 word format to html conversion project has notched up another few victories.
changes since last announced version are basically:
many many many bug fixes.
improved lists.
vastly improved header and footer support.
section support.
page numbering styles support.
improved handling of hyperlink fields.
and....
prelinary support for graphics !, yep given a gif/jpg/png inserted via the insert->picture->from file mechanism, mswordview can to date successfully find its way to outputting a graphic, though this feature is very alpha and based upon more that a little bit of guesswork.
http://www.csn.ul.ie/~caolan/docs/MSWordView.html
http://www.gnu.org/~caolan/docs/MSWordView.html
For more information: Caolan McNamara,
acua 2.11 - modem pool administration utilityDate: Tue, 15 Sep 1998 14:28:51 GMT
ACUA is designed to facilitate the administration of Linux systems hosting modem pools. ACUA's high-level goals are:
http://acua.gist.net.au/
For more information:
Adam McKee,
InfoPrism v0.0.3 - A General Document Processing SystemInfoPrism is a general document processing system that translates SGML source files to different output formats like HTML, Texinfo, LaTeX and plain text.
In addition to plain old SGML documents InfoPrism handles so-called SGML scripts as well. These are Tcl scripts using additional commands for document creation. The commands are * counterparts of SGML elements (e.g. `ul', `pre'). * shortcuts for multiple SGML elements (e.g. `liwul'). * simulate SGML facilities (e.g. `include').
Examples can be found in the `sgml' subdirectory of the distribution.
http://www.han.de/~racke/InfoPrism/
For more information:
Stefan Hornburg,
Fixkeys 0.1 - Mini-HOWTO on home/end/del/backspace keysDate: Tue, 15 Sep 1998 14:35:58 GMT
Fixkeys is a mini howto on howto get home/end/del/backspace behaving the way you want under linux. This howto comes with prepared config files and doesn't only describe what to do to get your keys to work but also why.
http://electron.et.tudelft.nl/~jdegoede/fixkeys.html
For more information:
Hans de Goede,
Linux PC-Emulator DOSEMU, new stable release: dosemu-0.98.1Date: Tue, 15 Sep 1998 14:51:27 GMT
The DOSEMU team is proud to announce DOSEMU 0.98.1, the PC Emulator for x86 based *nix. Please remember to consider this as ALPHA software.
DOSEMU is a PC Emulator application that allows Linux to run a DOS operating system in a virtual x86 machine. This allows you to run many DOS applications.
The DOSEMU PC Emulator can be downloaded from the following FTP sites:
ftp://ftp.dosemu.org/dosemu/
ftp://tsx-11.mit.edu/pub/linux/ALPHA/dosemu/
The binary distribution is statically linked against libc-5.4.46 and libX* from XFree-3.3.2.3. It should run on all current Linux distributions.
For more information:
The DOSEMU-Delopment-team,
http://www.dosemu.org/
ROADS 2.00 - a free Perl based Yahoo-like systemDate: Mon, 21 Sep 1998 10:31:31 GMT
ROADS version 2.00 is a free Yahoo-style system written in Perl. It is a collection of tools which can be used in building on-line catalogues.
ftp://ftp.roads.lut.ac.uk/pub/ROADS/roads-v2.00.tar.Z
For more information:
Martin Hamilton,
Loadmeter 1.20 - Linux/Solaris system stats utilityDate: Mon, 21 Sep 1998 10:33:20 GMT
Loadmeter is a useful little system monitoring utility I've hacked up to keep track of various system stats. It monitors: Load average, Uptime, Disk usageb,and Memory usage.
http://www.zip.com.au/~bb/linux/
For more information:
Ben Buxton,
Gtk-- 0.9.15 - C++ wrapper for gtkDate: Mon, 21 Sep 1998 11:08:08 GMT
Version 0.9.15 of Gtk-- is now available.
http://www.iki.fi/terop/gtk/
Gtk-- is a C++ wrapper for GTK, the Gimp ToolKit. GTK is a library for creating graphical user interfaces. Gtk-- is distributed under GNU LGPL.
Gtk-- provides C++ abstraction of gtk library. The C++ interface is kept very similar to the interface gtk has. Thus documentation and knowledge of gtk can be utilized for creating GUI applications using Gtk-- while still enjoying advantages C++ language can offer.
Gtk's homepage: http://www.gtk.org/ Gnome homepage: http://www.gnome.org/
(*) gnome and gtk1.1 widget support require newest versions from gnome cvs server.
For more information:
Tero Pulkkinen,
klp-0.2 - a print queue manager for KDEDate: Mon, 21 Sep 1998 11:22:12 GMT
It's here -- klp - a line printer queue manager for KDE -- Second (alpha) release 0.2.
klp is a GUI based replacement/wrapper for lpr/lpq/lprm (or similar in case of other types of print servers). It manages the print queue of printers. klp is intended for use with the K Desktop Environment http://www.kde.org/.
You can print by drag&drop documents from KDE's filemanager on it. You can view the queue and remove items from it.
klp can dock itself in the panel, still showing the printer status. The docked icon also allows printing by drag&drop.
http://rulhmpc49.LeidenUniv.nl/~klp
For more information:
Frans van Dorsselaer,
TkDesk 1.1 releasedDate: Mon, 21 Sep 1998 12:27:48 GMT
TkDesk is a graphical desktop and file manager for several types of UNIX (such as Linux) and the X Window System. It offers a very rich set of file operations and services, and gives the user the ability to configure most aspects of TkDesk in a powerful way. The reason for this is the use of Tcl/Tk as the configuration and (for the biggest part of TkDesk) implementation language.
http://people.mainz.netsurf.de/~bolik/tkdesk/
For more information:
Christian Bolik,
XFCE 2.1.0 - Window/Backdrop Manager and Toolbar for X releasedDate: Mon, 21 Sep 1998 12:37:49 GMT
XFce is now a set of applications including a powerfull Window Manager compatible with MWM(tm), OpenLook(tm), GNOME and KDE hints, a toolbar a backdrop manager and a system sound manager (NEW!) for X11. Unlike so many other X applications, XFce is very easy to use and to configure, thanks to menus, all mouse driven ! Features pulldown menus with color icons, 3D widgets, etc.
HTTP://xfce.penguincomputing.com/
HTTP://www.linux-kheops.com/pub/xfce/
HTTP://tsikora.tiac.net/xfce
Anonymous ftp sites :
ftp://antarctica.penguincomputing.com/pub/xfce
ftp://ftp.linux-kheops.com/pub/xfce-2.0.4
ftp://tsikora.tiac.net
XFce is a toolbar and a kind of desktop environment (XFce standing for XForms Cool Environment) With XFce, no need to learn any definition language, or type any configuration file. XFce does it itself! Just use the mouse to define your preferences. XFce provides an elegant and easy way to start all your X-Window applications, using nice color icons, popup menus, etc.
For more information:
Olivier Fourdan,
Subject: COMMERCIAL: Better Counter for LinuxDate: Mon, 21 Sep 1998 10:31:00 GMT
Better Counter - one of the leading CGI script for counting web pages - is now also available for Linux (on Intel hardware). Better Counter is the world's first counter that combines the following features:
- - Counts all pages of your site (depending on your service level)
- - Counts the click-through of your external links
- - Usability and clarity of the data presentation by using a Java Applet
- - Complete hits analysis within a freely customizable page structure
Better Counter is also available as FREE service.
http://www.better-counter.com/
For more information:
Stefan Ruettinger, http://www.better-homepage.com/
The Answer Guy 
AutoCAD for Linux? Not Yet. Sorry.fd0 --or--SCSI drive installation --or--Supressing cc: lines in Emacs' Mail replieschroot, twist, and other rescue-boot fun --or--Linux/Samba as a Primary Domain Controllerip masquerading --or--tty help --or--connect script failed --or--[linuxprog] more shuffling experiments --or--Conditional Execution Based on Host AvailabilityDesqview --or--Thanks for the pointer to uuencode sources.Download a Catch 22? --or--Important typo in Anti-Windows emulator rant --or--Greetings From Jim DennisWell, it's been another great month for Linux. We hear that Intel and Netscape are investing in Red Hat Inc. and Intel is joining Linux International.
So, everything is looking rosy for our favorite platform.
What could be better?
Well, I read an interesting editorial in ``;login'' the USENIX (http://www.usenix.org/) Association's monthly magazine. This is by Jordan Hubbard, one of the founders of the FreeBSD project --- and an employee at Walnut Creek.
He talks about the tendency of the freenix "clans" to fragment and duplicate development effort over relatively petty differences in licensing and --- more often as a result of the slithings and bites of "the snakes of Unrestrained Ego and Not Invented Here."
This fragmentation has been crippling the overall Unix marketplace for twenty years. The odd thing is that there is both a Unix "community" and a "marketplace." The members of the community tend to form "clans" which may bicker but mostly feel that they have mostly common goals. We'll argue incessantly over the advantages of a BSD'ish vs. a GPL license, or the superiority of 'vi' over 'emacs' or vice versa (I'm a heretic on that battle --- I use xemacs in "viper" -- vi emulation mode).
The Unix community has a long history of producing free software --- one that predates Linux, FreeBSD, X Windows, and even the Free Software Foundation itself. The FSF's GNU project was the first organized and formal effort to produce a fully usable system of tools that was unencumbered by corporate copyright (some argue that the "encumberances" of the GPL are even too much --- but that's back to the perennial clan feud; so let's skip it).
We may believe that Linux is the culmination of that effort. I hope it's not.
Jordan goes on to explain the FreeBSD attitude to software vendors that are expressing a renewed interest in the UNIX market and why he (and his associates) tell them "to port to Linux first (or at all)"
The FreeBSD support for running Linux binaries is apparently pretty solid (my use of FreeBSD has only required native binaries). It's possible that FreeBSD could be "fully Linux compatible" right down to compliance with the "Linux Standards Base." (It's likely to be easier for FreeBSD to achieve compliance than it will be for the various non-x86 Linux ports).
Jordan also goes on to speculate:
`` Say, for example, that someone fairly prominent in the Linux community popped up and told various users that they might want to give FreeBSD a whirl, just to check out what it has to offer lately. ''
Well, I'm probably not "fairly prominent" enough to fullfill Jordan's wish here. However, I've been saying that for years, here and in other fora. I think some of the SVLUG members are sick of hearing me suggest it.
My co-author (on the Linux book that we're writing) is a FreeBSD user. Some of my best friends favor NetBSD. My wife has been recently working for an outfit that uses FreeBSD for most of their desktop systems (only occasional spots of Linux) and Solaris for their servers. (The FreeBSD support for Japanese is apparently very good --- and it seems to be *much* more popular than Linux in Japan)
I've used FreeBSD and still recommend as an FTP server. I tend to stick with Linux for two reasons. The first is laziness, I've gotten much more used to Linux' quirks than FreeBSD's, and it's easy to pick up new CD's for Linux --- they're everywhere; I have to hunt around a bit for FreeBSD CD's.
However, I'm going to be trying a copy of 3.0 when it ships (I guess that will be near the end of this month). I'd suggest that all serious Linux students and enthusiasts try one of the BSD's --- FreeBSD for x86's; NetBSD for just about anything else; OpenBSD if your putting up an "exposed" system and allowing shell access to it.
Meanwhile I'll also suggest that you look at other operating systems entirely. Linux, FreeBSD, NetBSD, OpenBSD, Solaris .... they're all Unix. When you get beyond DOS/Windows/NT and MacOS all you see is UNIX.
However there's quite a bit more out there. You just have to dig for them. Here's one place where you can start:
http://www.starshine.org/OS/I wrote that page a long time ago --- but most of the links still seem to be alive (O.K. Sven moved --- so I had to fix one link).
Two notes of interest:
Amoeba is now "free"
Amoeba is a distributed OS (think Beowulf clusters with lots of OS level support for clusering, process migration etc). It was written as a research project by Andrew S. Tanenbaum of Vrije University (the author of Minix, and the text book from which Linus learned some of what he know about OS design). There was a legendary "flamewar" (actually just a public debate) on the alt.os.minix newsgroup about the merits of monolithic kernels (Linux and the traditional Unix implementations) vs. "microkernels" (Minix, MACH, the GNU HURD, NeXTStep, and many others).
To learn more about Amoeba:
http://www.cs.vu.nl/pub/amoeba/
The EROS project (Extremely Reliable OS) has apparently finally been completed (for its initial release). I've mentioned this project in my earlier columns --- it is a microkernel OS which implements a "pure capabilities" security and authority model. This is so unlike the identity and access control lists models we see in Unix, NT, Netware, VMS and other multi-user OS that it took me about a year to "unlearn" enough to get some idea of what they were talking about.
EROS is not a free system. However, there are provisions for free personal use and research.
You can read more about EROS at:
http://www.cis.upenn.edu/~eros/
(The FAQ's explanation of capabilities and its comparison to ACL's and identity based authority models is *much* better than anything that I found back when I first looked at this project a couple of years ago).
So, before you sing the praises of Linux to another potential convert --- consider your basis for comparison. If you've only only used DOS/Windows/NT and Linux --- you'll want to go back to school.
AutoCAD for Linux? Not Yet. Sorry.From david stankus on 24 Sep 1998
Hi, I was talking with Terry and he told me you may know of a way to use an AutoCAD14 compatible on the Linux OS platform? I'm an AutoCAD driver for pay and am about to build a machine and I'll need an OS for said machine. Do you think Linux is a good way to go? Thanks Dave
Last I heard there was no support for Linux from Autodesk. Although they originally developed on Unix, Autodesk has shifted almost completely to Windows in recent years --- and they've been cutting their margins and trying to make it on volume. The prices for their Unix versions were always much higher than the Windows versions --- so their perception of the market interest levels is probably a matter of "self-fulfilling" prophecy. (Naturally the market will appear to have greater demand for the version that costs one quarter the price).
So you probably won't get AutoCAD running directly. I also wouldn't try to run it under one of the Windows emulators that's available for Linux --- those are generally too slow and unstable for productive use on major applications. They are most suited to the occasional case where you need to get into Word or Excel to extract some data from a proprietary document.
Of course I could be wrong --- you should definitely call Autodesk and ask them. We've recently had Informix, Oracle, Sybase, Corel, IBM and other major companies announce product plans (and actually release products) for Linux. So, Autodesk might be jumping on this bandwagon to blow their own horn any time. Calls by real users, who are really interested in making an immediate purchase are bound to help. I've copied their webmaster on this message so that he or she (or they) can forward this along to the the appropriate parties. (I did search their web site at http://www.autodesk.com for Unix and Linux --- and there didn't seem to be any support for any PC based Unix -- though there was mention of AIX, HP-UX, and Sun [sic] --- that would presumably be Solaris/SPARC).
If that doesn't work you could try some of the native Linux CAD packages. There are a couple of these out there --- one is called "Microstation" from Bentley systems. It is available only in a "student version" and they won't sell a "fully support" edition for commercial/professional use at this time. There also one called VariCAD and another called Varkon. Actually there's a whole list of related products at:
http://www.linuxapps.com/cgi-bin/group.cgi?cad3d
... LinuxApps.com is an extensive site that lists a good cross section of the available Linux software (mostly commercial software in this case).
Two other favorite sites for Linux applications are:
- Christopher B. Browne's home pages:
- http://www.hex.net/~cbbrowne
Christopher is very active on the comp.os.linux.* newsgroups --- where he is often a voice of cool reason amidst the flames. His Linux pages covers DBMS (databases) more extensively than any others I've found.
... and:
- Linas Vepstas
- http://www.linas.org
Linas Vepstas should not be confused with Linus Torvalds. However, Linas does maintain a nice trim set of web pages devoted to "Linux Enterprise Computing." I particularly like Linas' commentary and annotations, including the occasional wisecrack. This is not "just another bookmarks" page.
These might not work like AutoCAD at all and I don't think they support the same document formats nor the "AutoLISP" programming/macro'ing language. However they might suit you.
Ultimately if your most important requirement is AutoCAD --- then you're probably stuck with Windows until Autodesk figures it out. Until then you could toss Linux up on a cheap little PC in the closet --- run an ethernet cable to it and access all your Linux applications remotely (via telnet and/or VNC or X Windows). If you use 'screen' and VNC it's possible to leave jobs running on the Linux box "detached" from your Windows box, so that the frequent reboots required by Windows won't disturb your other work. (My boxes at the house usually stay up for months at a time. I only occasionally reboot any of them --- usually to add hardware or install a new kernel.
Your "closet" server can be as modest as a 386 with as little as 16Mb of RAM and a 100Mb hard drive. (Actually it's possible to boot from a single diskette and do limited work in 8Mb of RAM or less --- but 16Mb and a hard drive is still a good idea).
Chicken and Egg (Catch-22) for Linux Download/InstallFrom Richard Santora on 14 Sep 1998
Question. Can you download Linux applications onto a floppy disk formatted under dos and then install to Linux?
You'd just mount the floppy (with a command like:
mount -t msdos /dev/fd0 /mnt/a
... and access the files under the /mnt/a (or whatever mount point you chose). You could then extract the members of a .tar.gz file with a command like:
cd /usr/local/from/floppy &&
tar xzf /mnt/a/mynew.tgz
... or you could use your favorite packaging commands to work with rpm and deb files.
Background. I am an inexperienced Linux Red Hat 5.0 home user. I selected the "everything" software installation choice from the installation CD onto my Dell XPS 60 with 40 Mb of Ram. I am using System Commander to use this pc to run dos based operating systems as well as Linux. I have internet access through Windows 3.1 and Windows 95. I am having difficulty getting a connection under Linux to my ISP, the Microsoft Network. (I have been able to get the modem to dial out using the Modem Tool and the Network Configurator in the X window Control Panel.) I would like to download one of the freeware PPP programs and also Netscape Navigator. When I download the PPP program using Windows 95, the file format extension will remain ".tar" or ".rpm" however; the Linux OS will not mount the floppy. I can get to the directory using "mdir" but I can not seem to get the program to install. Is there a work around?
If you can see it under Linux with 'mdir' (from the 'm-tools' package) than you can also copy it to one of your Linux native directories (such as /tmp) using the 'mcopy' command.
Read the 'mtools' man pages for details.
Another (Lose)-ModemFrom Barbara Ercolano on 20 Sep 1998
Hi James, I saw your "Answer Guy" page and I thought that maybe if you spare a few minutes you might help me with solving my connection problem. I have recently installed redhat linux on my PC and i am now trying to set up an internet connection. I have the chatscript the ppp-on and the ppp-off script the thing is that when i try to run the ppp-on nothing happens .
The syslog file says:
....kernel: PPP Dynamic channel allocation code copyright 1995 Caldera, Inc. ....kernel: PPP line discipline registered ....kernel: registered device ppp0 ....pppd[243]: pppd 2.2.0 started by root, uid 0 ....chat[244]: timeout set to 5 seconds
'winmodems' are NOT hayes compatible devices. They are little chunks of cheap hardware that can be used with proprietary (MS Windows only) drivers to emulate a modem --- and a measure cost in your system's CPU cycles.
this is my chatscript (/etc/ppp/chatscript)
TIMEOUT 5 "" ATZ OK ATDT08450798888 ABORT 'NO CARRIER' ABORT BUSY ABORT 'NO DIALTONE' ABORT WAITING TIMEOUT 45 CONNECT "" "ogin:" uk,ppp,myusername "ssword:" password
this is my /usr/sbin/ppp-on script:
#!/bin/sh # # ppp-on - Set up a PPP link # CFG_DIR=/etc/ppp LOCKDIR=/var/lock DEVICE=cua1 MYIP=0.0.0.0 if [ -f $LOCKDIR/LCK..$DEVICE ]; then echo "PPP device is locked" exit 1 fi /usr/sbin/pppd -d /dev/$DEVICE 38400 connect "/usr/sbin/chat -v -f $CFG_DIR/chatscript" defaultroute $MYIP: && exit 0 echo "PPP call failed" exit 1
this is my /usr/sbin/ppp-off script
#!/bin/sh
#
# ppp-off - Take down a PPP link
#
if [ "$1" = "" ]; then
DEVICE=ppp0
else
DEVICE=$1
fi
if [ -r /var/run/$DEVICE.pid ]
then
kill -INT `cat /var/run/$DEVICE.pid`
if [ ! "$?" = "0" ]; then
rm -f /var/run/$DEVICE.pid
echo "ERROR: Removed stale pid file"
exit 1
fi
echo "PPP link $DEVIVE terminated"
exit 0
fi
echo "ERROR: PPP link is not active on $DEVICE"
exit 1
pppd file /etc/ppp/myisp.options
... and let it contain all the other options specific to this ISP.
pppd will read the global options file (/etc/ppp/options) which in most cases should just contain the "lock" directive.
this is my /etc/ppp/options file:
0.0.0.0: /dev/cua1
The cua* devices are deprecated. Use ttyS* instead.
this is my etc/resolv.conf
search netcomuk.co.uk nameserver 194.42.224.130 194.42.224.131
Oddly enough you can use just about any nameserver on the Internet --- not just the one that your ISP provides. I've occasionally used the nameserver from one of my former employers when setting up a new machine at a customer site --- just long enough to have DNS to 'dig' up the more appropriate and closer nameservers (which should all have names or CNAMES of the form: ns*.foo.org in my not-so-humble-opinion).
This is all i can think of... mmhhh. I am not sure this is relevant but i tried to run minicom as well and that didn't work either, I mean it seems to be getting stuck... anuway... i hope you can help me...
If you can't get a boring old terminal emulation package like 'minicom', 'ckermit' talking to your modem --- then it is quite relevant to your problems running SLIP, PPP, fax, or anything else to that modem. The simplest think you can do to a modem is send it an ATZ and get an OK response. If you can't do that --- the modem (or your serial port, or your way of talking to the serial port) isn't working.
Thanks a lot for your time
love
Barbara
O.K. It's not a WinmodemFrom Barbara Ercolano on 20 Sep 1998
Hi James, thanks for your email... I am not sure whether i have a winmodem .... my modem's a Hayes Accura 336 External Fax Modem...
This leads us to the next possibility. I mentioned that it might be a problem between the OS and your serial hardware.
If you are using the correct /dev/ttyS* node --- then the next mostly likely problem is an interrupts conflict.
Is this a (PnP) "Plug and Pray" system? (Reboot and get into the CMOS setup program to look for those features). If so, try disabling that and setting all of your COM and printer ports to manually selected, non-conflicting ranges.
One of the bugaboos about Linux and most other Unix variants is that they tend not tolerate IRQ's conflicts the way that MS-DOS and Win 95 might. (This tendency in DOS and Windows probably leads to some of the intermittent hands and that you see with those OS'). So, you should not set your COM2 and COM3 ports on the same IRQ.
First, read the Linux Serial HOWTO. It will go into excruciating detail about the topic. Next play with commands like 'statserial' and 'setserial' and look at the /proc/interrupts and /proc/ioports psuedo-files. Also the boot up messages might help.
Also I think i have got the right port ttyS1 (cua1) for COM2... I have tried running minicom, and the init string appeared whith my cursor at the end of it, so i pressed enter and nothing happened after that (I should have got OK, shouldn't I?) I tried to enter my username and password (even though no login prompt appeared), and again nothing really happened I saw the modem blink but that's about it, so i exited minicom without resetting and looked at the syslog file... it said something about the line not being 8-bit clean and that bit 7 was set to zero.... all this has
I'm glad you looked in the syslog --- I don't think I remembered to suggest that in my earlier response.
This could be a cabling or IRQ problem. Make sure that the modem cable is a good one. I used to see problems with cheap cables that didn't have all of the handshaking lines connected and things like that.
absolutely no meaning to me whatsoever... I thought maybe you'd find it more illuminating.
Thanks a lot for your time
Cheers,
Barbara
Yet More on the Serial Port (it's not a WinModem) thing...From Barbara Ercolano on 21 Sep 1998
Hi ... it's me again , still tryin'... I've just done
cat /proc/interrupts
and this is what i've got:
0: 646864 timer 1: 2933 keyboard 2: 0 cascade 4: 2457 +serial 8: 1 +rtc 13: 0 matherror 14: 71407 +ide0
now the question is , shouldn't i get two lines saying serial if my modem was correctly installed??? The 4: 2457 + serial line is the mouse isn't it?
It used to say something about doing a 'dmesg' command or viewing syslog's /var/log/messsages shortly after a reboot --- with an example of the sorts of lines you should see from the kernel.
The dmesg command is to "display" (actually *re-display*) message that were generated during the boot sequence. All those messages that tell you what your kernel "found."
If this port works under DOS, Windows, et al, then you might use the "MSD.EXE" (Microsoft Diagnostics) package to tell you where DOS is finding the port. You can also use the "procinfo" command (from Linux) to get handy one page summaries of some system diagnostics and performance stats (including how many interrupts have been recieved and handled by kernel on each IRQ).
It may be that your serial port is set at a reasonable (non-conflicting) IRQ --- but that it's at one that the kernel doesn't probe by default.
To fix that you'd use the 'setserial' command to associate a give /dev/ttyS* device with an IRQ and set other characteristics on the line. It's also possible, though less likely, that you might have to use the stty command to set yet other characteristics of the tty lines.
Maybe this is where my problem is... what do you think? And if this is the problem , what do i need to do?
Since you seem to have a serial mouse --- try putting the mouse on that other serial port, and changing your start scripts (/etc/rc.d/$whatever) to have gpm, and X use that.
Actually on most Linux systems there's a symlink under /dev/ from "mouse" -> ttyS1 or -> psaux or whatever, and anther from "modem" -> ttyS* (or to the deprecated cua* "callout" ports). So, when you move a mouse or modem to a different serial port, you usually only have to change those symlinks according (just 'rm' the symlink and create a new one or use the 'ln -sf $device mouse' command.
cheers
Barbara
Buying DESQview and/or DESQview/XFrom Larry Herzog Jr. on 19 Sep 1998
Do you have any idea where someone can by the final releases of both Desqview386 and Desqview/X??
Unfortunately I don't. If they don't offer it direct from Quarterdeck (try calling and pestering for it via voice line) then I have no idea where you could get it.
I presume you ask because you found a references to DESQview on my web pages. The fact is that I gave up on DV (and MS-DOS in general) about five years ago --- when I switched to Linux full time.
Linux will run on just about any hardware that could support DESQview/386 --- and it's DOSemu package is just about as good as DV ever got. XFree86, the X Windows system supported by Linux (and the other freenix varieties) is much more stable and modern than DESQview/X ever was (although I did like dwm --- their quick little window manager, and "appman" (applications manager).
I think it's a pity that Quarterdeck as done so poorly. However, I must say I saw it coming. That's one of the reasons I left their employ when I did (long before they gutted the whole department I had been in).
I think that the best things that Quarterdeck could do now are:
- Release DESQview, QEMM386, the DESQview API programming kits etc all under the GPL. [I think one of the other Open Source(tm) licenses would work fine, too; for example, the NPL style with Quarterdeck filled in as originator. -- Heather]
- Encourage Caldera (current owners of DR-DOS --- and a major distributor of Linux) to incorporate these into their DR-DOS package (which is now targeted toward embedded x86 systems)
- Release the DV/X sources, dwm and the related utilities.
- Start writing Linux and freenix applications --- and adding some professional polish and consumer touches to various freeware projects and sell collections of these add-ons.
- Offer paid Linux telephone support (Quarterdeck had the most effective and efficient tech support department that I've ever seen or worked with --- with the most expeditious and sensible call escalation methodology. If they haven't obliterated that from their corporate memory --- they could rock! I, the Linux Gazette "Answer Guy" would call them in a heartbeat if they were offering commercial support.
But, alas and alack, it is not likely to be. Sorry I can't help you more than that.
Supressing cc: lines in Emacs' Mail repliesFrom Ning on 23 Sep 1998
Hi Jim,
I found your email address from the Linux Gazette web site. Hope it's ok to ask you a question. I use emacs to read and reply email. Could you please tell how to set up the .emacs file such that the CC line(s) is automatically removed when replying an email?
Many thanks,
Ning
That would depend on which mail reader you're using under 'emacs'.
I use mh-e -- the emacs front end to the Rand MH mail handling system. When I hit "r" for "reply" it asks "Reply to whom:" (my choices are "all" or <enter>/(none))
If I choose "all" or "cc" than mh-e will add the cc: lines to my headers. Otherwise, if I just hit enter it will only include the address(es) listed on the From: line.
If you use RMAIL or VM or Gnus you answer will be different. There are several mail readers for emacs --- and you'll want to read the help and 'info' pages for the one you're using to find out how to customize it. Sometimes you have to resort to reading the elisp sources, particularly the comments in order to under an emacs package. This is particularly handy if you intend to do any customizations of you're own .emacs configuration file, since that is also written in elisp.
In VM and Gnus you can use "r" to reply ("R" to reply with the original quoted) and "f"/"F" to "follow" (do a "wide reply"). Even if you pick the lower case options you can yank in (quote) the original message. The capitalized forms just save you an extra couple of keystrokes. Gnus can be used as a mail reader as well as a newsreader --- and allows you to see your mail folders in the same sort of "threaded" mode as you might be used to from newsreaders.
Gnus will allow you to view mail and news that are stored in just about any format. I use it to view some of my MH folders (particularly on the rare occasions when I can get into the Linux Kernel mailing list digests.
VM allows you to "view" your standard "mbox" mail folders --- which the the same sorts as you'd get from using /usr/ucb/mail (mailx), 'elm' and/or 'pine'
RMAIL is the oldest and least featureful of the emacs mailreaders. It stores your messages in a single folder in the "Babyl" format. I've never used it and the info pages don't reveal any obvious difference between replying to "just the sender" and to the whole group of recipients (what 'elm' users think of as "r" vs "group" or "g" replies).
The reason I use MH folders is because it allows me to use glimpseindex and get meaninful results when I search for multiple keywords in proximity to one another. For instance, earlier this evening I wanted to find any copy of the "comp.unix.admin" FAQ that I might have mailed myself. Using the command glimpse "admin;faq" I was able to zero in on the specific item in my "ref" (reference) folder in one shot. (I let the command run for a couple of minutes in the background and continued by writing --- so I don't know how long the search took).
When I used 'elm' a search like that wouldn't have helped much --- after finding the right folder I'd still have to find the message and cut and paste that portion of the file out to what I was working on.
Another feature that's important to me is that I can have multiple drafts in progress. I have a whole folder for drafts, and once a draft is started it doesn't get "lost" just because I have to set it aside and handle more pressing issues, or go look up something.
Naturally you can use Supercite or other "citation/quoting" packages with any of the emacs mailreaders to manage exactly how your attributions look to them. I've tried Supercite and don't much like it. There are also a couple of emacs PGP interfaces that are designed to link to your news and mailreaders, and the "tools for MIME" (tm). to help compose, view, and extract those pesky MIME attachments. Of course you also have 'ispell' available within a keystroke or two. (I have mine bound to [F3],$ to check the word at point and [F3],% to check the whole buffer --- however this is usually not terribly handy for my writing since I tend to have so many abbreviations, filenames, and non-words in my work).
One nice think using a mailreader under emacs is I also have easy access to the emacs "calendar" ([F3],C in my configuration). From there I can add an entry to my "diary" using "i,d" which I can check (using [F3],D in my case).
So, I get mail inviting me to lunch on the tenth of next month and I hit a couple of keystrokes (usually [F9] to switch to the message buffer, a couple of 'vi' keystrokes to "Yank" the message or a couple paragraphs into a kill buffer, [F3],C to bring up the calendar, a couple of keystrokes to navigate to the 9th of next month, "id" to "insert a date/diary entry" and "p" (another 'vi' key) to paste that note into place).
Now I just try to remember to check my diary folder at least a couple times a day. I usually put two entries in for each date. One is a one-liner that says: "tomorrow" and the other gives the time and details. It might refer me to the "todo" folder, where I'll find the original message.
Similarly I use my mh/aliases folder (e-mail address book) as a telephone and postal address book as well. I do this just using comments (start comment lines with a semicolon --- just as you might in a sendmail /etc/aliases file).
Before I give people the impression that I'm some sort of emacs fanatic I should point to that I detest the default emacs keybindings (which I think were devised by sado-masochists on bad drugs). I use 'viper' mode as the default for most buffers, and I have fairly long list of custom bindings to save my sanity for the things that old 'vi' was just never meant to do (like splitting the screen between two buffers and launching "shell-prompt" buffers and other editor "packages" like "dired" (file/directory management buffers).
I rarely use "dired" (I prefer 'mc' --- midnight commander) and almost never use "gnuscape gnavigator" --- WM Perry's w3 mode. It's an impressive bit of work --- but I like lynx for text mode --- and Netscape's Navigator is better if I have to go into X anyway.
There are a number of "helper" modes that seem to be more of a hinderance than a help to me (like the AucTeX, LaTeX, TeX, and html-helper modes). They all seem to take a radically different approach to structured text editing than I'm willing to embrace. Also I don't like emacs' abbreviations mode -- since I like to have abbreviations that including punctuation and it considers all of those to be word boundaries and won't let me use them easily. (The old 'vi' abbreviations feature was very unassuming --- you gave it a list of characters to watch for and a list to expand those into --- it just did).
I'm told that most of the things I do in emacs are now possible in 'vim' --- and I use 'vim' frequently to do quick edits. I don't use 'emacs' (actually xemacs) as 'root' -- so all configuration and /etc/ files are maintained in whatever version of 'vi' happens to be lying around. That's almost always 'vim' these days. However, I don't know any of the 'vim' improvements --- they aren't "portable" to other vi's or to emacs, so they'd be a loss to invest any time in learning, at this point. I use xemacs because it supports a mixture of "applications" and utilities (modes and packages in its own terminology) that I can use from any old text mode login.
As an "OS within an OS" xemacs is a bit of a pain. Installing a new package, like the 'calc' scientific calculator mode (think HP 48 calculators with all sorts of algebraic expression processing analsysis and features to export to GNUplot), and BBDB (the "big brother database" --- a sort of "Rolodex" (tm) utility, is difficult. It's easy if you just want to wedge it into the same directories with the other elisp code --- but I like to put new packages that I install into /usr/local or /usr/local/opt (which is symlinked from /opt) --- so I can tell what I put there from what my distribution installed. That takes extra work.
Anyway -- I'll finish my rant by appending my latest .emacs file. Actually my .emacs only reads:
(load (expand-file-name "~/.elisp/init.el")) |
... and my ~/.elisp/init.el is where all the action is:
;; Jim Dennis' .elisp/init.el file (setq inhibit-startup-message 't ) (setq load-path (cons (expand-file-name "~/.elisp") load-path )) (column-number-mode 1) (line-number-mode 1) (setq display-time-day-and-date 't) (display-time) (setq version-control 't) (indented-text-mode) (setq fill-column-default 72) (setq fill-column 72) (setq fill-prefix " ") (auto-fill-mode) (setq viper-mode t) (require 'viper) ;; Custom Functions: (defun insert-output-from-shell-command (commandstr) "Insert output from a shell command at point" (interactive "*sInsert From Command:") (shell-command commandstr 1)) (defvar my-mh-folder-keys-done nil "Non-`nil' when one-time mh-e settings made.") (defun my-mh-folder-keys () "Hook to add my bindings to mh-Folder Mode." (if (not my-mh-folder-keys-done) ; only need to bind the keys once (progn (define-key mh-folder-mode-map "a" 'visit-mh-aliases) (define-key mh-folder-mode-map "b" 'mh-redistribute) (define-key mh-folder-mode-map "T" (mh-put-msg-in-seq nil "t")) (define-key mh-folder-mode-map "j" 'mh-next-undeleted-msg) (define-key mh-folder-mode-map "k" 'mh-previous-undeleted-msg) (setq my-mh-folder-keys-done 1) ))) (defun my-mh-letter-keys () "Hook to add my bindings to mh-Letter Mode." (progn (define-key mh-letter-mode-map '[f4] 'mh-yank-cur-msg) (define-key mh-letter-mode-map '[f5] 'mh-insert-signature) (define-key mh-letter-mode-map '[f10] 'mh-send-letter) (setq fill-column 68) (setq fill-prefix " ") (auto-fill-mode) )) (add-hook 'mh-folder-mode-hook 'my-mh-folder-keys) (add-hook 'mh-letter-mode-hook 'my-mh-letter-keys) ( defun paragraph-fill-justify-forward () "Fill and justify paragraph at point and move forward" (interactive "*") (fill-paragraph ()) (forward-paragraph)) ( defun save-and-kill () "Save and kill current buffer" (interactive) (save-buffer) (kill-buffer (current-buffer))) ;; Some stuff for mh-e: (setq mh-progs "/usr/bin/mh/") (setq mh-lib "/usr/lib/mh") ;; Something for Gnus (to save outgoing stuff) (setq gnus-select-method '(nntp "news")) ;; (setq gnus-secondary-select-methods '(nnmh "~/mh")) ;; (setq message-default-headers "Fcc: ~/mh/gnus.mbox\n") ;; (setq message-default-mail-headers "Fcc: ~/mh/gnus.mbox\n") ;; (setq message-default-news-headers "Fcc: ~/mh/gnus.mbox\n") ;; (setq gnus-author-copy "|/usr/lib/mh/rcvstore +gnus.out") (defun my-gnus-summary-keys() "Hook to add my bindings to Gnus Summary Mode." (progn (define-key gnus-summary-mode-map '[f4] (progn (gnus-summary-tick-article)(gnus-cache-enter-article)) ))) ;; Start gnuserv -- so gnuattach, gnudoit, and gnuclient will work: ;; (server-start) (gnuserv-start) ;; Quick access to my aliases file from my mh-e folder view ( defun visit-mh-aliases () "Visit my MH aliases file" (interactive "") (switch-to-buffer (find-file-noselect "~/mh/aliases"))) ;; For Tools for MIME: MH version (load-library "tm-mh-e") ;; For Supercite ;;(autoload 'sc-cite-original "supercite" "Supercite 3.1" t) ;;(autoload 'sc-submit-bug-report "supercite" "Supercite 3.1" t) ;;(add-hook 'mail-citation-hook 'sc-cite-original) ;; For XEmacs color/terminal support: (when (eq (device-class) 'color) (set-face-background 'default "black") ; frame background (set-face-foreground 'default "cyan") ; normal text (set-face-background 'zmacs-region "cyan") ; When selecting w/mouse (set-face-foreground 'zmacs-region "blue") (set-face-font 'default "*courier-bold-r*120-100-100*") (set-face-background 'highlight "blue") ; ie when selecting buffers (set-face-foreground 'highlight "green") (set-face-background 'modeline "blue") ; Line at bottom of buffer (set-face-foreground 'modeline "white") (set-face-font 'modeline "*bold-r-normal*140-100-100*") (set-face-background 'isearch "cyan") ; When highlighting while (set-face-foreground 'isearch "black") (setq x-pointer-foreground-color "black") ; Adds to bg color, (setq x-pointer-background-color "blue") ; This is color you really ) (defun my-quick-buffer-switch () "Quick Switch to previous buffer" (interactive "") (switch-to-other-buffer 1)) (custom-set-faces) (setq minibuffer-max-depth nil) (custom-set-variables '(user-mail-address "" t) '(query-user-mail-address nil) ) ;; ... and I'll learn to make real use of abbreviations -- eventually (abbrev-mode 1 ) (setq abbrev-file-name (expand-file-name "~/.elisp/abbreviations")) (quietly-read-abbrev-file) ;; My personal key binding for non-vi'ish stuff: (global-set-key '[f3 ?0] 'delete-window) (global-set-key '[f3 ?1] 'delete-other-windows) (global-set-key '[f3 ?2] 'split-window-vertically) (global-set-key '[f3 ?4] 'split-window-horizontally) (global-set-key '[f3 ?!] 'insert-output-from-shell-command) (global-set-key '[f3 ?$] 'ispell-word) (global-set-key '[f3 ?%] 'ispell-buffer) (global-set-key '[f3 ?b] 'switch-to-buffer) (global-set-key '[f3 ?B] 'buffer-menu) (global-set-key '[f3 ?c] 'shell) (global-set-key '[f3 ?C] 'calendar) (global-set-key '[f3 ?d] 'dired) (global-set-key '[f3 ?D] 'diary) (global-set-key '[f3 ?f] 'find-file) (global-set-key '[f3 ?F] 'find-file-at-point) (global-set-key '[f3 ?m] 'mh-rmail) (global-set-key '[f3 ?n] 'gnus-no-server) (global-set-key '[f3 ?k] 'kill-buffer) (global-set-key '[f3 ?r] 'insert-file) (global-set-key '[f3 ?o] 'other-window) (global-set-key '[f3 ?s] 'save-buffer) (global-set-key '[f3 ?S] 'save-some-buffers) (global-set-key '[f3 ?w] 'w3-follow-url-at-point) (global-set-key '[f3 ?x] 'execute-extended-command) (global-set-key '[f3 f1] 'manual-entry) (global-set-key '[f3 f7] 'auto-fill-mode) (global-set-key '[f3 space] 'set-mark-command) (global-set-key '[f7] (quote paragraph-fill-justify-forward)) (global-set-key '[f8] (quote my-quick-buffer-switch)) (global-set-key '[f9] (quote other-window)) (global-set-key '[f10] (quote save-and-kill)) (global-set-key '[f11] (quote kill-this-buffer)) (global-set-key '[f12] (keyboard-quit)) ;; end: JimD's .elisp/init.el |
There is undoubtedly some cruft in there that will make real emacs/elisp gurus gnash their teeth in disgust. I don't pretend to know anything about lisp programming (other than that it has an inordinate propensity for parentheses). I mostly use two key, unshifted, key sequences that are prefixed with [F3] so that I rarely have to use the 'viper' mode's [Ctrl]+z (switch to emacs mode) or the viper command mode "\" command (escape next keystroke to emacs mode).
There are more things I'll do eventually. That's one of the reasons I adopted Linux and xemacs in the first place --- the tools have enough depth that I can always learn more about them. They don't limit me.
Floppy/mount Problems: Disk Spins, Lights are on, No one's Home?From Jonathan on 24 Sep 1998
I have built a custom system just for Linux, but the only problem I have is that when I try to mount a floppy, the light just comes on and the disk just spins. The motherboard is a new Tyan that is full of PCI PnP. Any ideas would be greatly appreciated. TIA
-=Jonathan=-
How is this diskette formatted? What if you use the mtools commands on a DOS formatted floppy?
Do any associated messages appear in your syslog (/var/log/messages)? Are you sure that you have the flopp support compiled into this kernel? (Perhaps you have to load a module)?
If it really is a PnP issue you could look for the PnP tools for Linux (these are userspace tools, mostly without kernel patches --- though I'm pretty ignorant on the details. I generally recommend disabling any BIOS PnP ("Plug and Pray") features when installing Linux --- particularly on a dedicated Linux server where you don't have to accomodate some other OS.
If all else fails, boot up with a copy of DOS (DR-DOS even) and access the floppy that way --- or try a tomsrtbt (Tom Oehser's Root/Boot distribution on a floppy -- the best Linux rescue diskette I've found). Naturally these have to use the floppy --- so it should be pretty obvious if there's some hardware failure or incompatibility.
Conditional Execution Based on Host AvailabilityFrom Vladimir Kukuruzovic on the Linux Users Support Team mailing list on 20 Sep 1998
Hi, regarding to your answer guy message
Conditional Execution Based on Host Availability
From the L.U.S.T Mailing List on 07 Aug 1998
#!/path/to/perl
$ping = Ping -c 1 10.10.10.10;
exec ("program") if $ping =~ /100\% packet loss/;
What's wrong with a simple:
ping -c 1 $target && $do_something $target || $complain
... where you fill $do_something and $complain with commands that you actually want to run on success or failure of the 'ping'.
That's what shell "conditional execution operators" (&& and ||) are for after all.
your program does not work well with current release of net-tools and ipv6 support.
you should rewrite it this way:
ping -c 1 -q $target 2> /dev/null | fgrep "1 packets received" \
/dev/null && $do_something $target || $complain
I should not have to use 'grep' and parse the output from the ping command. It should return an error level that reflects the results.
If it doesn't do that in some new release --- I'll hack it back in myself. (Ideally it might offer an option to specify a threshold lossage percentage --- on which it returns an error. But adding a command line option to 'ping' for this might be "gilding the lily" --- and adding anything to it (since it is, by nature, an SUID program) is a unpleasant prospect.
kind regards,
Vladimir
p.s. the original program would say that everything is ok when $target is in DNS, but is not reachable (no route to host)
By that I presume you're referring to the fragment of perl code. Mine did not seem to do this (since I tested it with several degenerate cases).
IP and Sendmail Masquerading over a CablemodemFrom Marty Leisner on 22 Sep 1998
I read your column in the May LG. (I'm behind on my reading )
I recently (last month) got a cable modem and hooked up a masquerading firewall...
On the firewall machine, I have the rule:
ipfwadm -F -p deny ipfwadm -F -a m -S 192.168.0.0/24 -D 0.0.0.0/0
I got this of the IP-masquerade howto...
I'm not sure if its the same as the rule:
ipfwadm -F -a accept -m -S 192.168.1.0/24 -D any
I've heard conflicting reports about using 192.168.0.* and 192.168.255.* (the first and the last of this range). So I don't recommend it. If you needed a very large network of "private net" (RFC 1918 --- aka RFC 1597) addresses you could also use 172.16.*.* through 172.31.*.* --- that's sixteen adjacent class B networks, or your could use 10.*.*.* --- a full class A.
Also, you sendmail .mc:
-- FEATURE(always_add_domain)dnl FEATURE(allmasquerade)dnl FEATURE(always_add_domain)dnl FEATURE(masquerade_envelope)dnl MASQUERADE_AS($YOURHOST)dnl
adds always_add_domain twice...
Is $YOURHOST defined someplace (I just went through the work of configuring sendmail a few weeks ago).
The Feynman problem solving Algorithm
--- Murray Gell-mann in the NY Times
Linux/Samba as a Primary Domain ControllerFrom Prophet on 22 Sep 1998
I looked over your answer to another gentalmen's question about the PDC for linux. My question is very similar. Can you tell me how to configure samba to be the Primary Domain Controller. I am have two other clients on my network, NT server (stand alone), and a Win95 client. I want both of these machines to log in to Samba. But this is not possible untill I get a PDC established. I understand that NT can handle the job well, but that isn't any fun. If you could help I would appreciate it.
=Prophet=
However, I hope I didn't imply that this is already available as production quality code. Last time I talked to Jeremy Allison (one of the core members of the Samba team) he said that they had some beta level code out there. I just noticed a note on Freshmeat (http://www.freshmeat.net) that Samba 2.0 alpha version #6 has just shipped. So that would be a good place to start looking.
The Samba home pages are at: http://samba.anu.edu.au/samba It's a good idea to remember that Samba is not a Linux specific project. Although many of the developers and users are running Linux, many others are running various BSD flavors and other forms of Unix.
Your question is probably a pretty common one. There is a Samba NT Domain FAQ at: http://samba.gorski.net/samba/ntdom_faq/samba_ntdom_faq.html
... and yours is the first question listed.
As with any Open Source (TM) project, if this isn't moving fast enough to meet your needs, consider contributing some time, programming skill or other real support to the effort.
Partition your HD before you try to use it.From Adam Ray on 23 Sep 1998
Yep!
I have an adaptec 1505 SCSI card (no bios). an a seagate 1gig SCSI HDD. I want to install linux to boot from a floppy, and then use the SCSI drive as the root. But when i put in the rescue disk and at the boot: prompt type "rescue aha152x=0x340,12,7,1" it finds the card then finds the drive, but it comes up with an error that the kernel can't load at something like "10:" i'm not sure if that is the exact number, but i' mnot a that machine right now. I was wondering if you could give me, or know where there is a blow-by-blow installationi tutorial for non-partitioned SCSI drives.
There are also man pages on 'fdisk' and Lilo --- and there is a pretty good Lilo guide (usually included as a .dvi or .ps PostScript file to provide the diagrams and illustrations).
I realize that you won't be using Lilo in the usual way to load this copy of Linux (since a boot sector installed on your SCSI hard drive will never be reached by your BIOS's boot up sequence). However, reading the docs about the way its "usually" done can help understand the exception cases in any event.
Another problem I see in this case is that you're trying to "rescue" a "new installation." That doesn't work. You use a "rescue" diskette to fix an damaged or misconfigured existing installation. To install a new system use an "installation" diskette. Most of the friendly installation programs out there these days (Red Hat, S.u.S.E. etc) will not handle your situation particuarly well. They should install just fine --- but they may not offer the option to "boot from diskette."
So, use their installation to get to the point where it wants to run Lilo --- and let it do that even (no harm in it, even though you don't have a BIOS that will call on it). Then use the rescue diskette to boot into the running system and read the BootDisk HOWTO for advice on creating a custom boot diskette.
You could also use Tom's Root/Boot (tomsrtbt at http://www.toms.net/rb) as the basis for your custom boot disk. It is the easiest single diskette distribution to customize (of the ones that I've tried).
please E-mail me
Thanks,
Adam
Shuffling Lines in a FileFrom David Stanaway on the Linux Programmers Support Team mailing list on 20 Sep 1998
Now I'm trying to shuffle the order of the lines in a text file without reading in the whole file... Does anyone have any advice, code, etc on this? If I can read in the whole file, this is simple, but I might want to shuffle a file several megs long.
What do you mean by shuffle?
I think the approach I'd take is to lock the file from access by whatever programs and/or processes are intended to read the data out of it.
Then I'd "index" the file --- search through it finding all of the line boundary offsets and their lengths. I'd then use an standard shuffling techniques on that index file. The problem with "shuffling" a normal text file on line boundaries is the variable record lengths. So we create a table of offsets and lengths to those --- and all of the offset/length pairs are of a fixed size.
So I could use the index file and "shuffle" it with the following psuedo code:
- open index file
- while read index file entry (readbuf)
- pick a random place to put it
load the "place to put it" entry (writebuf)
swap these entries in read and write buf.
write both buffers
If the intent is to shuffle the files by some other criteria (arbitrary vs. random) when you'd modify the above algorithm accordingly. If the criteria for resequencing has to do with the data in the files (i.e. your "sorting" the file) you'd have a bit more work ahead of you.
... actually I'd optimize this a bit by read x entries into a buffer, for looping through that, and maintain a few write bufs into random locations into the file. For example I might load 100 entries in the read buffer and up to ten unique randomly selected write buffers. For each of the 100 read buffer entries I'd randomly select among the open write buffers (1 to 10) and randomly select a place in that buffer to put it). At the end of the for loop I'd write everything back out, read the next read buff, select more write buffs, and so on until the end of the file.
Every entry in the index file will have been exchanged with some random entry at least once --- and the average will be two. There is a small chance that a given entry would be swapped out of and back into the same location (which is usually a good feature of a shuffling algorithm).
Then I'd open the original text file and the shuffled index file and I'd walk through the shuffle file sequentially reading offset/length pairs and using them to seek into the text file and copy to a new file. After each seek I'd do one sanity check --- it there should be a newline there, and as I was copying I'd do another, there should be no newlines between my offset and the end of my length. I'd abend with an error message if either sanity check failed, or if any seek failed (the original file was shortened while I was shuffling).
Finally I'd mv the new file back into place.
This algorithm assumes that you have files with variable length records delimited by newlines. It also assumes that you are not disk space constrained (that you have at least enough room to make one full copy of the file to be shuffled + enough for an index file. Oddly enough the index file could, in some degenerate circumstances be several times the size of the original file. (that happens if all of the lines in the old file were only zero or one characters long and that your offsets and lengths are 32 bits each.
Note that I chose to use a file for the index rather than RAM. If I'm guaranteed that the file will have a "reasonable" number of lines I can build that in memory --- thus simplifying the code somewhat. I chose the method that I describe so that you could as easily shuffle multi-gigabyte files as multi-megabyte.
The whole program could probably run in less than a 100K and work on any size file that was supported by your OS.
You could also look at the sources for the GNU 'sort' utility. I handles arbitrarily large inputs (using sequences of temp files which then merged together).
If you open a file for reading, the only space it takes up is the read buffer, so if you read a line at a time, the memory usage depends on how you are shuffling.
If you wanted to reverse the file, you could jsut be writing the lines you read to another file.
[deletia]
Then you may like to read the source file from the tail first. I don't know how to do this in C, or C++, but it is possible in Java.
You really need to say more about what you mean by <Shuffle>
David Stanaway
Shuffle: to resequence. to place a group of objects into some arbitrary or random order.
The problem at hand is a classic CS homework assignment. It has quite a bit to do with the variable length nature of the objects to be sorted. We can't do this with "in place" editing (arbitrary seeks and writes into the orginal file) because the record we're trying to move might overwrite two or more record fragments at its destination.
When you are editing a file (the whole thing being in memory) there are ways that the editor's buffer handling handles the issue --- look at the sources to 'vi' or some other smaller, simpler editor and find out how they "delete a line" in terms of their internal data structures. These don't work well for files since you might end up re-writing from the current offset to the end of the file for each replacement.
If the lines are of a fixed length it is much easier, we can skip the indexing step and we can, if we wish, shuffle the file "in place" --- without the copying. Naturally we'll still want to lock the file (or move it to someplace where other processes and programs won't be giving us concurrency fits).
Dear answer guy..From Josh Assing on 15 Sep 1998
Thank you very much!
Cheers
-josh
I am a woeful windoze database programmer that must interface with the almighty unix environment... I am in search of source code (c is best) for uudecode/uuencode.
Another good place to look for these sorts of things is at the master repository of GNU software:
ftp://prep.ai.mit.edu
... or at its principal mirror: ftp://ftp.gnu.org
... where it should be part of the "sharutils" package.
Also I think you should be able to find the sources at the FreeBSD, NetBSD, and OpenBSD sites:
- http://www.freebsd.org
- http://www.net.org
- http://www.open.org
... respectively.
In general the best places to find any Linux software (most of it is available in source form) are:
http://www.freshmeat.net
and:
http://lfw.linuxhq.com
Freshmeat is nice for keeping up on new and recent package releases. It is updated daily and there are usually about a dozen new packages or versions available every day. Today is light --- there's only nine items --- there were thirty one on the two previous days.
It gives a brief (one paragraph) description of each package and a usually three links to "Download" it or view its "HomePage" or "Appindex Record."
LFW (Linux FTP Watcher) is a forms based search engine that indexes the top twenty or so Linux FTP sites.
The problem with requests to help find the source code is that many of the most basic packages (the ones that have been part of most Unix implementations forever) are bundled together in a few "base" packages (like sharutils for uuencode/uudecode).
Although I don't know where most of them are I think the sources for commands like 'cp' and 'ls' are in binutils, and for commands like 'cut' and 'tail' are in fileutils.
So, unfortunately, it can be a bit difficult to find the source to a given package. Yggdrasil and some traditional Unix flavors used to offer a "whence" command to point to the sources for any command. However, the current crop of distributions doesn't seem to offer this handy feature.
On RPM based distributions you could use a variation of the RPM command to find out which package included a given file like so:
rpm -qf /usr/bin/uuencode
... which reports sharutils-4.2-5 on my S.u.S.E. 5.3 system. Different distributions package these differently. However, given that you could then look on your CD's or on the FTP sites for a "sharutils-4.2-5.SRPM.rpm" or a "sharutils-4.2-5.spm" (these being different naming conventions for representing "source" RPM's).
You can read my back issues or look to http://www.rpm.org to learn more about the RPM package management system --- and a few searches should net you considerably comparison and debate about its merits and faults relative to the "tarball" (Slackware pkgadd) and Debian packaging systems and formats.
I was directed to www.ssc.com; and then to you... Hopefully; you can be of assistance..
Thanks
Cheers
-josh
Psuedo tty Becomes UnusableFrom Scott R. Every on 21 Sep 1998
i have a system which has been running for a while(actually a number of systems) after a bit the ttyp0 port is no longer available when telnetting in. it doesn't list anywhere as being used, but it doesn't work!
can you offer any suggestions?
thanx
s
The /dev/ttyp* devices are for "psuedo" tty's --- these are used by rlogind, telnetd, xterms, screen and many other programs. There are usually many of these psuedo tty's on a system.
Normally a daemon that uses a psuedo tty searches through the list and uses the first one that it can open. There is another approach used by some other forms of Unix --- and supported in recent kernel whereby the daemon makes a request of a sort of "dispatcher" device which then provide it with the number of the next available pty/ttyp device. This is referred to as "Unix '98 PTYs Support" in the linux kernel -- and I've heard it referred to as "ptmx" (psudo-tty multiplexing, or something like that). In the case of the Linux implementation the pty's can be dynamically generated under the "pts" virtual filesystem (which is a bit like the /proc filesystem in that it doesn't exist on a "disk" anywhere --- it simply provides a filesystem abstraction of the system's in memory data structures). Linux 2.2 will also probably support a "/devfs" --- another virtual filesystem which makes all of the entries under /dev into dynamic entries.
Of course, none of that applies to your situation. That's just the "vaporware report" on the future of the Linux kernel.
If there really is no process that still owns the ttyp0 in your case then it might be a bug in your kernel. I'd check the permissions of the device node to see if they are changing (or to see if there is something that's just blowing the device node away), then I'd look through the "Change Logs" for the recent 2.0.3x kernels. It might be that you are bumping into one of the bugs that Alan Cox and crew have been fixing. If you aren't running a 2.0.35 or 2.0.36 kernel --- consider trying it to see if that solves the problem.
To be honest I haven't seen a good description of the whole pty*/ttyp* mess or a decent explanation of what problems the Unix '98 ptmx design is supposed to solve. I've heard that pty's and ttyp's are paired off in "master/slave" pairs that have something to do with providing different device nodes for control (ioctl()?) and communications over the channel. If any of our readership knows of a good treatise on the topic, please pass me a pointer or mail me a copy.
Will the "Real" freshmeat Please Get Bookmarked?From Richard C on 14 Sep 1998
You referenced http://freshmeat.org in this article, when I assume you meant http://freshmeat.net... Freshmeat.org does point to freshmeat.net, but you can't rely on a newbie to find it, can you?
-) Keep up the good work
Cheers
Richard Cohen
"Virtual Hosting" inetd based services using TCP WrappersFrom Nick Moffitt on 23 Sep 1998
Hullo thar!
You mentioned that you might mail me some example conf files to show me how you did all those nifty things we talked about on Saturday. I'm actually working on setting up a chrooted system for public use here at Penguin, so any examples would be keen (and no, I haven't searched through the answer guy archives yet).
Here's a couple of trivial examples (I don't have a copy of 'chrootuid' handy on this box, but you can find it at cs.purdue.edu's "COAST" security tools archive).
# hosts.allow This file describes the names of the hosts which are # allowed to use the local INET services, as decided # by the '/usr/sbin/tcpd' server. # $Revision: 1.2 $ by $Author: root $ on $Date: 1998/02/08 09:35:55 $ # in.ftpd: 127.0.0.1: ALLOW [email protected]: [email protected]: ALLOW in.ftpd: ALL: DENY [email protected]: ALL: twist /bin/echo "Not Available\: Go Away!" in.ftpd: 192.168.1.: ALLOW ALL: 127.0.0.1 ALL: 192.168.1. |
These are order dependent. The first rule that matches will be one one that tcpd uses --- so the ALL: rules at the bottom are significant. If I put them first -- they'd over-ride the more specific ones --- whereas here, they don't.
In this case my "normal" IP address on eth0 is 192.168.1.3 (canopus.starshine.org). For playing with tcpd I add an eth0:1 alias (ifconfig eth0:1 192.168.1.127). That would work as easily if it was a second interface --- ethernet, PPP or whatever.
Now, if I telnet localhost or telnet to canopus, everything works fine. But if I telnet to the ...127 address it tells me to go away. The hosts_options and the hosts_access(5) man pages list a number of replacement operators like %a for the source IP address of the request and %d for the "daemon" name (argv[0] of the process). These parameters can be used in the shell commands.
Note that the "twist" option is completely different than the "spawn" option. "spawn" seems to imply "ALLOW" and spawns a process that is run in addition to the service. This process is spawned with it's standard file descriptors all set to /dev/null --- so it doesn't interact with the user at all.
The twist option runs an alternative to the requested service. Thus, if you request my web server I might "twist" that into a cat command what will spit out an HTTP redirect with a simple 'echo' or 'cat' command like so:
[email protected]: ALL: twist /bin/cat /root/web.redirect
I don't know of a way to to call for both a twist and a spawn -- but you can write a script (or better, a small C wrapper) to run the desired "spawn" commands in the background (with outputs directed to /dev/null, of course).
Naturally, of course, you'll want to follow proper coding practices for "hostile" environments when you're writing something that will be "exposed" to the Internet.
Matt Bishop, at the UC Davis has some excellent papers on this topic, and presents his own, more robust, implementations of the system(), and popen() library calls --- which are called msystem(), and mpopen() in his library.
Matt's site is at: ftp://nob.cs.ucdavis.edu/pub/sec-tools (I think there's a web site there, too).
My first article, "CHAOS: CHeap Array of Obsolete Systems" (see Linux Gazette, volume 30, July, 1998), describes a somewhat bazaar set of circumstances that led to my building a network of aging PCs, running Red Hat Linux. A number of readers contacted me after reading it, asking me how it was going and if there would be a follow-up article - this is it!
A few PCs, an Operating System, and networking hardware form the largest part of the infrastructure necessary for the kind of software systems that I want to design and work with, but systems cannot run on basics alone. A little administration, a few shell scripts, and a couple of utility programs will bring it all together into what I want it to be: a distributed system.
Distributed algorithms often consist of several identical copies of a single program, each running on a different computer in the network. I can write and debug a single copy on my big '486 machine, named "omission," but that's just the first step. Debugging the final product, running on seven machines simultaneously, requires me to develop a way to remotely start a process on each machine, to see how well that process is running, and to kill them all, if necessary, centralizing their trace file data so I can figure out what went wrong.
This article describes what I added to my system to make this all happen.
I have worked on many Unix networks in the past. I thought nothing of using the remote shell command, "rsh," to switch to some other machine in the network, to get access to its local data. I thought nothing of it, that is, until I wanted to work like that on my own network.
>From omission, there are three ways I can think of to switch over to one of the '386 machines. I can use the telnet command, which puts up a login prompt, asking me for a userid and password. I can "rlogin" to another machine, which asks me for a userid, but not a password, if the system files are properly set up. Finally, there is "rsh" which lets me go about my business without so much as a userid if all the system files are just so; getting them just so, I find, is a black art.
I knew that my userid's home directory, /home/alex, needed a ".rhosts" file with my userid: a single line with "alex" in it. I knew too, that the /etc/hosts.equiv file played a part, but I wasn't sure exactly how, so I started reading, and asking a lot of questions. Most references to these system files, it seemed, were more interested in telling me how to keep others out instead of welcoming them in!
I am not above a brute force approach to solving problems. I'll bet that a smart sysadmin reading this article might be appalled by my methods, but they worked for me and sometimes that's enough of a reward.
My domain name, as you may recall from the first article, is "chaos.org" and my seven '386s are named after the seven deadly sins. User alex has a home directory on omission, which is nfs mounted on each of the seven other machines. My /home/alex/.rhosts and each /etc/hosts.equiv file contain exactly the same eight line entries, as follows:
omission.chaos.org alex greed.chaos.org alex lust.chaos.org alex anger.chaos.org alex pride.chaos.org alex gluttony.chaos.org alex envy.chaos.org alex sloth.chaos.org alexI am not sure where I got my initial ideas about how this all worked, but what's listed above works on my systems and again, that's enough for me for now.
I wanted to have at least some reasonable time-of-day clock synchronization, so I added a "clock reset" command to the boot process. The following lines were added to each remote machine's rc.local file:
# reset date and time from server date `rsh omission "date +%m%d%H%M"`
I boot omission first and wait for it to come up before starting others because it contains the /home directory that each of the other machines must mount. When each of the other machine boots, it sets its time-of-day to that of omission, accurate to the minute.
There is only one copy of /home/alex/.rhosts file, but every system has its own copy of /etc/hosts.equiv. Maintaining a set of eight identical copies of anything is not a pleasant task, especially when you are making subtle changes, trying to get them all to work in your favor.
One way to handle this is to copy the file to a diskette and load it onto every machine, but that's too much of a pain. The sophisticates might have a separate partition for such files, local to their main server, and remotely mounted everywhere else. Since I am both the system administrator and the user community, I overlapped things a bit.
I created a /home/alex/root subdirectory, owned by root, and copied each of these volatile system files into it. That way I could make changes in only one file and distribute it more easily than from a floppy. I copied /etc/hosts to that area, additions to large system files, like rc.local, and all the shell scripts that the root user on each machine might use, too. I'll discuss these next.
I might want to reset the time-of-day clock manually, so I used the same clock set command (above) in a shell script named "settime":
#!/bin/csh -f # # settime - resets data and time from server # date `rsh omission "date +%m%d%H%M"`
I might be monitoring some long running tests and, being the nervous type, I might want to watch the overall system performance. Here is my "ruptime" (which stands for remote uptime) script:
#!/bin/csh -f
#
# ruptime - remote uptime displays system performance
#
cat /etc/hosts \
| grep -v localhost \
| awk '{ print $3": ";system("rsh "$3" uptime") }'
This displays the loading on each of my machines and I use this as a high level indication of overall system performance. The word loading, by the way, means the number of processes on the operating system's ready queue, waiting for the cpu. (The cpu is usually busy running the active task. The three numbers uptime displays are the 1, 5, and 15 minute loading averages - see the uptime man page for more information.) If I see what might be a problem, all zeros e.g., I can follow up with other commands that give me more specific information.
The "ps" command presents process status for every process in the system. The addition of a "grep" for my userid, alex, will limit the display to only the ones I happen to be running, but it will include the grep command itself. Additional greps with a "-v" option can reduce the content of the display to just those processes that I am interested in monitoring:
#!/bin/csh -f # # rps - remote process status # ps -aux | grep alex \ | grep -v rps \ | grep -v aux \ | sed -e "s/alex\ \ \ \ \ /`hostname -s`/" \ | grep -v sed \ | grep -v hostname \ | grep -v grep
The "sed" command substitutes the remote host name for my userid. I use this script along with the rsh command to display the status of remote processes:
omission:/home/alex> rsh pride rps pride 218 0.4 7.0 1156 820 1 S 13:34 0:02 /bin/login -- alex pride 240 0.7 6.6 1296 776 1 S 13:37 0:01 -csh pride 309 0.3 1.8 856 212 1 S 13:41 0:00 ser pride 341 0.0 4.4 1188 524 ? R 13:41 0:00 /bin/sh /home/alex/bin
Careful readers might notice that the ruptime script displays uptime for all machines on the network, while rps targets only one machine. My general version of rps works through a pair of programs named "rstart" and "psm," controlled by a script named rpsm:
#!/bin/csh -f # # rpsm - remote process status for my userid # rstart psm
The program rstart.c accepts the name of an executable in the user's path:
#include <stdio.h>
#include <chaos.h> /* a list of all the remote host names in chaos.org */
main(argc, argv)
char *argv[];
int argc;
/*
** rstart.c - start a process named in argv[1] on all remote systems
*/
{
int i, j, pids[NUM];
char command[64];
/*
** insist on at least two command line arguments
*/
if(argc < 2) {
printf("\n\tUsage: %s <process> [<parameters>]\n\n", argv[0]);
exit(-1);
}
close(0); /* avoid stdin problems if we run in the background */
/*
** initialize the remote process name
*/
strcpy(command, argv[1]);
if(command[0] != '/') /* prepend path if nec */
sprintf(command, "%s%s", Bin, argv[1]);
/*
** append any other command line parameters specified
*/
for(i=2; i<argc; i++) {
strcat(command, " "); /* append a blank */
strcat(command, argv[i]); /* append a parameter */
}
/*
** start remote tasks
*/
for(i=0; i<NUM; i++) {
if(i) /* pause between starts */
sleep(1);
if((pids[i] = fork()) == 0) {
if(execl("/usr/bin/rsh", "rsh", Hosts[i], command, NULL) == -1) {
perror("execl()");
exit(-1);
}
}
}
/*
** wait for all processes to complete
*/
for(i=1; i<NUM; i++)
waitpid(pids[i]);
return(0);
}
The rpsm script (above) runs the rstart program, which runs psm:
#include <string.h>
#include <stdio.h>
main()
/*
** psm.c - lists process status for my userid
*/
{
FILE *fp;
int len, pid1, pid2;
char host[32], *p;
char line[128];
/* request name of local host */
gethostname(host, sizeof(host));
if((p = strchr(host, '.')) != NULL)
*p = '\0'; /* cut domain name */
len = strlen(host);
/* our proc id */
pid1 = getpid();
/* request listing of all process' status */
fp = popen("ps -aux", "r");
while(fgets(line, sizeof(line), fp) != NULL) {
if(strstr(line, "alex ") == NULL)
continue; /* not our userid */
if(strstr(line, "psm") != NULL)
continue; /* skip ourself */
sscanf(line, "%*s %d", &pid2);
if(pid2 >= pid1)
continue; /* skip higher pids */
/* replace userid with host name */
strncpy(line, host, len);
printf("%s", line);
}
return(0);
}
Here is a sample run:
> rpsm pride 218 0.0 7.0 1156 820 1 S 13:34 0:02 /bin/login -- alex pride 240 0.0 6.6 1296 776 1 S 13:37 0:01 -csh pride 309 0.0 1.8 856 212 1 S 13:41 0:00 ser pride 487 38.3 5.4 1240 636 ? S 14:17 0:01 csh -c /home/alex/bin greed 222 35.8 7.3 1240 636 ? S 14:17 0:01 csh -c /home/alex/bin . . . sloth 201 36.5 7.1 1240 636 ? S 14:17 0:01 csh -c /home/alex/bin
The rstart program concept can be expanded to gather a good deal more than process status. I created script-program pairs that dump trace and log files from a particular machine. I can also kill a remote process by name on all my remote machines by running rstart with k.c:
#include <string.h>
#include <stdio.h>
main(argc, argv)
int argc;
char *argv[];
/*
** k.c - kills the named user process
*/
{
FILE *fp;
int pid1, pid2;
char line[128];
char shell[32];
char host[32];
char proc[16];
if(argc < 2 || argc > 3) {
printf("\tUsage: k <process_name> [noconf]\n\n");
exit(-1);
}
/* get process name for strstr line compares */
sprintf(proc, "%s ", argv[1]); /* add blank */
sprintf(shell, "-c k %s", proc); /* our mom */
pid1 = getpid();
/* get host for print message */
gethostname(host, sizeof(host));
/* request listing of all process' status */
fp = popen("ps -aux", "r");
while(fgets(line, sizeof(line), fp) != NULL) {
if(strstr(line, "alex ") == NULL)
continue; /* not our userid */
if(strstr(line, shell) != NULL)
continue; /* skip shell */
if(strstr(line, proc) == NULL)
continue; /* must match */
sscanf(line, "%*s %d", &pid2);
if(pid2 >= pid1)
continue; /* skip higher pids */
/* kill the process */
system(line);
sprintf(line, "kill -9 %d", pid2);
if(argc != 3)
printf("%s: %s\n", host, line);
}
return(0);
}
All of the above programs and scripts were pasted into this article from tested source code, but I removed blank lines and made other cosmetic changes to make it more readable and to manage its size. Please accept my apologies in advance for any difficulties you may experience. I cannot assume any liability for your use of the above, so you must do so at your own risk.
I feel like I am ready now to start developing software according to my original plans. I hope some of my solutions will help you too, should you try this yourself.
My next step is to develop a central "manager" process, running on omission, that will display real-time status and behavior of the system of distributed processes running on all the other machines. I want to be able to "drive" the system by sending requests to one of the processes on a randomly chosen machine, and then to "watch" how all the remote processes interact in developing their response. Each remote process interacts with a local "agent" process running in parallel with it. Each agent will send messages back to the manager, telling it what state that part of the system is in; the manager combines these remote states into a global state display for the entire distributed system. If you're interested in this sort of thing, stay tuned!
This project has been quite a learning experience for me. I am proud of what I've built and I hope these simple tools will motivate some of you to give this a try - perhaps with only three or four systems, perhaps with more than the eight machines that I combined. Home networking is in vogue now, and developing software that takes the greatest advantage of a network cannot be far behind. Try this if you dare, and be ready for the future.
There seem to be quite a number of small networks, either at home or at small companies, which use Windows (be they 3.1 or 95/98/NT workstation) clients, and a Linux box as a dial-up router to the InterNet at large. A common setup is to use IP masquerading, so that the the clients can hide behind a single IP address, with diald, the dial-on-demand daemon, so that the Linux box connects as and when required. This works pretty well
The real problem with this is that users on the Windows clients have no real indication of the state of the dial-up link. So, if a connection fails to materialise (ie., your web browser cannot find a URL), you may not know whether the URL doesn't exist, or the dial-up link didn't come up.
Dialmon was originally conceived as a simple monitor to provide the Windows user with some information about the link. In its original form, it comprised a single daemon process dialmon which ran on the Linux box in parallel to daild, and a client dialm to run on the Windows client.
The dialmon daemon connected to the diald daemon using the laters control fifo, requesting that state information be retured via a second fifo which dialmon created. When dialm clients connected, the state information provided by diald, suitably filtered to remove un-needed stuff, was passed back to the dialm client, which could then display the current dial-up state. Two sorts of information were displayed, the actual link state (up, down, connecting ...) and message output generated by diald's connect and disconnect scripts.
So if, for instance, you pointed your browser at http://www.linuxgazete.com (sic) then you could see the link come up and, when the browser failed to find the URL, you hopefully realised that you should have pointed it at http://www.linuxgazette.com.
This seemed a big improvement, but there were still some more minor niggles. Firstly, the web browser would often time out a URL before the dial-up link came up (particularly in the early evening!), which meant trying the URL a second time. Of course, by this stage the dial-up link had often just gone down again on account of there being no traffic. Secondly, if you ran sendmail or similar on the Linux box and used a mail reader on the Windows client, then to get an urgent item of mail on its way from the Linux box to your ISP (or to check for incoming mail), you'd need to indulge in some trick like using your web browser simply to force the link up. Try explaining that one to your users!
So, dialmon was extended to allow control over the link Actually, these changes spanned three releases, but the effect is that users on the Windows clients, can, subject to various access controls, request that the link be brought up, request that it be taken down, and even request that diald itself be stopped and restarted with a different configuration (which appeared because I need to use two ISPs). This feature also has the side effect that if diald crashes, then dialmon will restart it.
The access control can be based either on the host on which dialm is running, or on a user name with password checking. The latter can be set up to use Linux box user names which do not have login access and which are different to the Windows user's real user name (if any) on the Linux box.
One or two users asked whether dialmon could show some load information, ie., the amount of traffic going through the dial-up link. Having done nothing myself, someone (Jim Mathews, thanks) provided some code to give an indication of this via an icon in the Win95/98/NT system tray. This has now been extended to show a pair of bars in the dialm window, one for transmit and one for receive, which show, at least approximately, the percentage of the dial-up bandwidth which is being used.
This is quite useful if you are doing a large download, to get an idea of whether it is worth carrying on, or whether you should kill the download and try later (while America sleeps, maybe).
So, how does one set all this up? The distribution (ftp://sunsite.unc.edu/pub/Linux/system/daemons/dialmon-0.4.tgz.THISONE) contains the Linux and Windows sources, plus prebuilt Win31 and Win95/98/NT clients. Once you have built and installed the Linux dialmon daemon, you need to configure it.
I'll describe the setup I use at home (which is also the office). The network comprises two Linux boxes, of which one called quaking runs diald and sendmail, plus a Windows 3.1 machine called rover which my wife Tina mainly uses, and a Windows 95 machine called gingling which I use. I want to be able to bring the dial-up link both up and down, and to switch between two ISPs, and I want to allow Tina to bring the link up and down, but not to switch ISPs.
The dialmon daemon uses two configuration files, /etc/dialmon.conf to specify its own setup, and the options to be given to client machines, and /etc/dialmon.users to specify options to be given to specific users. These are shown below:
/etc/dialmon.conf
[host]
port 7002
force 90
fifo /etc/diald/diald.ctl
allow up
ddconf Planet "-f /etc/diald.conf.planet"
ddconf Demon "-f /etc/diald.conf.demon"
This specifies that dialmon listens for dialm clients on port 7002 and will force the dial-up link up for 90 seconds (after which, if there is no traffic on the link, diald will shut it down). The allow up line specifies that any client dialm is allowed to bring the link up. The two ddconf lines specify ISP configurations; the text in "...." is the arguments to diald.
/etc/dialmon.users
[mike]
passwd dialmon
allow up
allow down
allow ctrl
[tina]
passwd dialmon
allow up
allow down
The users file specifies the access for myself and Tina. The lines passwd dialmon indicates that when mike (or tina) connects, the password supplied should be checked against that for the user dialmon rather than mike (or tina).
Lastly, the daemons run from a startup script /etc/rc.d/init.d/diald which is linked as /etc/rc.d/rc3.d/S99diald (I use the RedHat distribution which has SysV style startup scripts):
/etc/rc.d/init.d/diald
#!/bin/sh
#
# diald Start or stop the dialer daemon
#
. /etc/rc.d/init.d/functions
if [ ! -f /etc/sysconfig/network ]; then
exit 0
fi
. /etc/sysconfig/network
# Check that networking is up.
[ ${NETWORKING} = "no" ] && exit 0
[ -f /sbin/ifconfig ] || exit 0
# See how we were called.
case "$1" in
start)
echo -n "Starting dialer demon: "
/sbin/route del 0.0.0.0
# Start dialmon, which will in turn run diald with the Demon
# configuration, and will if necessary kill off the ppp0
# PPP daemon
#
daemon /usr/sbin/dialmon -rDemon -pppp0 -b28800
[ -f /proc/sys/net/ipv4/ip_dynaddr ] &&
echo 1 > /proc/sys/net/ipv4/ip_dynaddr
echo ""
;;
stop)
# Shut dowm. Don't use killproc because we want a SIGTERM and
# not a SIGKILL, so that dialmon can terminate diald (and maybe
# pppd as well).
#
echo -n "Shutting down dialer daemon: "
[ -f /var/run/dialmon.pid ] && (
kill -TERM `cat /var/run/dialmon.pid`
rm -f /var/run/dialmon.pid
echo -n "dialmon "
)
echo ""
;;
*)
echo "Usage: diald {start|stop}"
exit 1
esac
exit 0
The -rDemon argument to /usr/sbin/dialmon tells dialmon to initially run diald with the Demon configuration. The -ipppp0 argument says that, when dialmon restarts diald, it should kill any ppp daemon running for the ppp0 link (it looks in /var/run/ppp0.pid), and -b28000 says that the nominal link bandwidth is 28000 baud (used for the receive and transmit displays).
I've found that dialmon makes life easier for myself, and my wife (who claims to be a computerphobe but loves eMail) uses it all the time; I've also installed it on the office network of one of my clients. Quite a number of people have eMail'ed me about it (thanks for the bug reports, suggestions, contributions, not to mention the thanks) so I'd like to think that its made life a bit better for them as well.
As I mentioned above, it should be available from ftp://sunsite.unc.edu/pub/Linux/system/daemons/dialmon-0.4.tgz.THISONE (THISONE on account of an upload error, please ignore the tgz file without the extension unless it's been sorted!) Please feel free to eMail me at .
The fifth International Linux Congress was held June 3-5, 1998, at Cologne University in Germany. This was only a few days after the Linux Expo held at Duke University in North Carolina, U.S.A. (May 28-30), which made for a few tired participants including some of the speakers who attended both events. On the first day of the Congress, intensive tutorials on various subjects were offered in both English and German. These included ``Becoming a Debian Developer'' by Bruce Perens, ``KDE Programming'' by Kalle Dallheimer and Matthias Ettrich, and ``ISDN4 for Users'' by Klaus Franken.
The talks began the next day, opening with the keynote speaker, Jon ``maddog'' Hall. Jon's talk, entitled ``Economics of Computing for the 21st Century'', began with a historical survey of computers. He talked about early computer systems, which cost three times more than what his parents paid for a house and were much less powerful than modern home systems which are now inexpensive enough to buy with credit cards. He predicted that in the near future, one will be able to buy a computer in the check-out line at the local supermarket. Indeed, at least two grocery stores in Germany already sell inexpensive PCs. He ended his talk by expressing the need for Linux to reach the ``Moms and Pops'' of this world and with a plea to lobby not just for Open Source software but for open hardware standards.
After the keynote speech, participants got to choose between two talks running in parallel. The format was forty-five minutes per speaker, with breaks every ninety minutes. The majority of the talks were held in English, to accommodate guests from the United States, Canada, England and the Netherlands, with a few held in German. Although it was possible to attend up to six talks a day, some participants expressed regret that they couldn't attend all the interesting talks due to simultaneous scheduling.
During the breaks, participants had an opportunity to explore the various booth displays. S.u.S.E., a company which makes a popular German Linux distribution, offered free demo CDs with their newest 5.2 version. O'Reilly had a nice book display with offerings in both English and German. The KDE group had a very popular display showing off their attractive desktop environment. John Storrs, who also presented a talk, had a display demonstrating the use of Real Time Linux for the purpose of CAD/CAM design.
The University also provided the Congress with a small number of Linux computers connected to the Internet for those participants who found it hard to be away from the keyboard for too long. Among the many interesting talks presented on the first day was one entitled ``Designing an Ext2fs Resizer'', given by Theodore Y. Ts'o. Theodore has made contributions to the development of the Ext2fs system in the past and is presently working on a method for enlarging and reducing the size of an Ext2 file system and adding B-tree support.
Christian Gafton, one of the programmers from Red Hat, gave a talk entitled ``Migration to glibc''. He said the use of glibc is no longer as controversial in the fast-moving Linux world as it was when Red Hat first adopted it. With the latest versions of glibc available on the Internet, the most common problems with porting code to the library occur when programmers write code which is dependent on bugs which exist in the old libc libraries, or when programmers use bad programming practices such as the use of #include<linux/foo.h> instead of the recommended #include<sys.foo.h>.
A few sessions were purposely left open. The organizers called these ``Birds of a Feather Sessions'' where the congress attendees could get together for ``spontaneous and informal meetings for presentation or discussion of any interesting subject''. Some people from Debian took advantage of this opportunity to discuss various issues concerning their Linux distribution.
@lay:please note that ASCII246 is an o with an umlaut
That evening, participants got a chance to socialize and experience a bit of German culture. The social event was held at a local pub reserved for the Linux Congress. There was a wonderful smorgasbord and the waiters were very quick to fill our beer glasses with Cologne's famous kölsch. Everyone enjoyed themselves and hopefully some long term computer friendships were formed.
The talks continued on the third day with interesting topics such as IEE-1394 (also known by the commercial name Fire Wire) by Emanuel Pirker. Emanuel designed support for this technology as part of his work as a university student in Austria. Warwick Allison gave an interesting account of the QtScape Hack, in which a small group of programmers created a port of Netscape to Qt in a five-day programming spree while on vacation in Norway.
The final panel board discussion was perhaps the most interesting, and certainly the most contentious topic of the congress. The subject was GNOME vs. KDE. (See Linux Journal, May 1998.) Participants included Miguel de Icaza of the Gnome Project, Kalle Dalheimer of the KDE project and Bruce Perens who helped to define the Open Source License. The people from the KDE project, which is already in its second year, felt that Linux was in need of a comfortable desktop environment. Linux has already captured the server market, but has not reached the desktop widely because the technical capabilities required are beyond that of the average user. They also felt that Linux is about choice, and that since the GNOME project is now being financed by Red Hat, people would be unduly influenced to use GNOME.
The people from GNOME countered that Red Hat had no influence on the direction of their project, and the reason KDE is not included in the Red Hat distribution is because of its use of the Qt-toolkit. Many people were of the opinion that although the KDE project is further ahead than the GNOME project, its use couldn't be wholeheartedly embraced by the Linux community because of the non-GNU license of the Qt-toolkit. They fear a similar situation to the Open Group who recently changed the licensing policy of the X server. Some members of the audience informed the Congress that a project to make a GNU clone of the Qt-toolkit was underway, and other audience members expressed the opinion that the two KDE and GNOME groups should work more closely, but still acknowledge the positive creative push of healthy competition. Any hurt feelings were laid to rest and all friendships renewed as we said our goodbyes at the O'Reilly Publishing House.
The O'Reilly team invited participants of the Linux Congress ``zum Klönen bei Kölsch'' or for a chat and beer. Participants agree the fifth annual Linux Congress was a success and look forward to next year's Congress, which the organizers promised us would not be quite so soon after next year's Linux Expo!
Psst, wanna have some fun? Try client/server computing. It's like talking through two tin cans and a taut string, upgraded to the computer era. Linux has all the tools you need. You are already using client/server computing in applications such as Netscape, telnet, and ftp. And it's easy to write your own client/server apps, maybe even useful ones.
Client/server computing links two different programs (the client and the server) over a network. For practice you can even skip the network by letting Linux talk to itself. So read on even if you aren't attached to a network. (But your Linux installation needs to be configured for networking.)
A very common form of client/server computing uses BSD sockets. BSD stands for Berkeley Software Distribution, an early version of Unix. Logically, a BSD socket is a combination of IP address and port number. The IP address defines the computer, and the port number defines the logical communication channel in that computer. (In this usage a port is not a physical device. One physical device, e.g. an Ethernet card, can access all the ports in the computer.)
Linux Journal ran a nice three-part series on network programming by Ivan Griffin and John Nelson in the February, March, and April, 1998, issues. The February article contains the code to set up a skeleton client/server pair using BSD sockets; it includes all the plumbing needed to get started. You can download the code from SSC, then use this article to start playing with more content.
After downloading the file 2333.tgz, expand it with the command tar&nsbp;-xzvf 2333.tgz. Rename the resultant file 2333l1.txt to server.c, and the file 2333l2.txt to client.c. Edit server.c to delete the extraneous characters @cx: from the start of the first line, and either delete the last line or make it a comment by enclosing it between the characters /* and */. Similarly, delete the last line of client.c, or make it a comment. Compile server.c with the command gcc -oserver server.c; similarly compile client.c using gcc -oclient client.c.
The server runs on the local computer, so it only needs to know its port number to define a socket. The client runs on any computer, so it needs to know both its target server computer and the server's port number. You have thousands of port numbers to play with. Just don't use a port that is already taken. Your file /etc/services lists most of the ports in use. I found that port 1024 worked fine.
Now I said you didn't need to be connected to a network, but you do need to have your computer configured for networking to try this out. In fact, this code won't run for me if I use the generic name localhost; I have to give the explicit name of my computer. So assuming you are set up for networking, start the sever by typing
server 1024 &and then start the client by typing
client hostname 1024where hostname is the name or the IP address of your computer. If things work right, you will see output similar to the following:
Connection request from 192.168.1.1 14: Hello, World!The first line gives the IP address of the client, and the second line is the message from the server to the client. Considering all the code involved, this would be a good entry for the World's Most Complex "Hello, World" Program Contest! Note that the server keeps running in the background until you kill it with the commands fg and ^C (ctrl-C).
/* local test of client-server code */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
char name[256] = "";
char buffer[256] = "";
void client(char *buffer)
{
printf("%s", buffer);
fgets(buffer, 256, stdin);
}
int main(int argc, char *argv[])
{
int year, age;
sprintf(buffer, "Please enter your name: ");
client(buffer);
strcpy(name, buffer);
sprintf(buffer, "Hi, %sPlease enter your year of birth: ", name);
client(buffer);
year = atoi(buffer);
age = 1998 - year;
sprintf(buffer, "Your approximate age is %d.\nEnter q to quit: ", age);
client(buffer);
return(0);
}You don't have to be an expert at C code to see how this works. The simulated server (main) sends the string "Please enter your name" to the simulated client (client) through the array buffer. The client prints the string, reads the name as a string from keyboard, and returns that string through buffer. Then the server asks for the year of birth. When the client collects it as a string, the server converts it to a number and subtracts it from 1998. It sends the resultant approximate age back to the client. We are done now, but because the client needs a keyboard entry before returning, the server requests that a "q" be entered. More sophisticated coding could eliminate this unnecessary awkwardness. This simulated client/server illustrates passing strings between server and client, asking and responding to questions, and doing arithmetic.
Copy the above code into an editor and save it as localtest.c. Compile it with the command gcc -olocaltest localtest.c. When you run it you should get output like:
Please enter your name: joe Hi, joe Please enter your year of birth: 1960 Your approximate age is 38. Enter q to quit: qNow let's turn this into a real client/server pair. Insert declarations into server.c by changing the beginning statements of main to read:
int main(int argc, char *argv[])
{
int i, year, age;
char name[256] = "";
char buffer[256] = "";
char null_buffer[256] = "";
int serverSocket = 0,The application-specific code in server.c is towards the end. Replace it with the following:
/* * Server application specific code goes here, * e.g. perform some action, respond to client etc. */ sprintf(buffer, "Please enter your name: "); write(slaveSocket, buffer, strlen(buffer)); for (i = 0; i <= 255; i++) buffer[i] = 0; /* get name */ read(slaveSocket, buffer, sizeof(buffer)); strcpy(name, buffer); sprintf(buffer, "Hi, %sPlease enter your year of birth: ", name); write(slaveSocket, buffer, strlen(buffer)); for (i = 0; i <= 255; i++) buffer[i] = 0; /* get year of birth */ read(slaveSocket, buffer, sizeof(buffer)); year = atoi(buffer); age = 1998 - year; sprintf(buffer, "Your approximate age is %d.\nEnter q to quit: ", age); write(slaveSocket, buffer, strlen(buffer)); close(slaveSocket); exit(0);This is almost the same as the server code in the simulated client/server, except that we read and write slaveSocket instead of calling the function client. You can think of slaveSocket as the connection through the socket between the server and client.
The client code is very simple. Insert declarations into client.c by changing the beginning statements of main to read
int main(int argc, char *argv[])
{
int i;
int clientSocket,Find the application specific code near the end of client.c and replace it with the following:
/*
* Client application specific code goes here
* e.g. receive messages from server, respond, etc.
* Receive and respond until server stops sending messages
*/
while (0 < (status = read(clientSocket, buffer, sizeof(buffer))))
{
printf("%s", buffer);
for (i = 0; i <= 255; i++) buffer[i] = 0;
fgets(buffer, 256, stdin);
write(clientSocket, buffer, strlen(buffer));
}
close(clientSocket);
return 0;
}Again, this is almost the same as the client code in the simulated client/server. The main differences are the use of clientSocket, the other end of slaveSocket in the server, and the while statement for program control. The while statement closes the client when the server stops sending messages.
Recompile server.c and client.c and run them again as before. This time the output should be something like:
Connection request from 192.168.1.1 Please enter your name: joe Hi, joe. Please enter your year of birth: 1960 Your approximate age is 38. Enter q to quit: qNow you can really play: try running multiple client sessions that call the same server, and if you are on a network try running the server on a different computer from the client. The server code is designed to handle multiple simultaneous requests by starting a process for each client session. This is done by the fork call in server.c. Read the man page for fork to learn more.
Insert declarations into server.c by changing the beginning statements of main to read:
int main(int argc, char *argv[])
{
char buffer[256] = "";
int i, serverquit = 1, clientquit = 1;
int serverSocket = 0,Replace the application-specific code towards the end of server.c with the following:
/*
* Server application specific code goes here,
* e.g. perform some action, respond to client etc.
*/
printf("Send q to quit.\n");
sprintf(buffer, "Hi, %s\nS: Please start chat. Send q to quit.\n", inet_ntoa(clientName.sin_addr));
write(slaveSocket, buffer, strlen(buffer));
for (i = 0; i <= 255; i++) buffer[i] = 0;
while (serverquit != 0 && clientquit != 0)
{
status = 0;
while (status == 0)
status = read(slaveSocket, buffer, sizeof(buffer));
clientquit = strcmp(buffer, "q\n");
if (clientquit != 0)
{
printf("C: %s", buffer);
for (i = 0; i <= 255; i++) buffer[i] = 0;
printf("S: ");
fgets(buffer, 256, stdin);
serverquit = strcmp(buffer, "q\n");
write(slaveSocket, buffer, strlen(buffer));
for (i = 0; i <= 255; i++) buffer[i] = 0;
}
}
printf("Goodbye\n");
close(slaveSocket);
exit(0);Insert declarations into client.c by changing the beginning statements of main to read:
int main(int argc, char *argv[])
{
int i, serverquit = 1, clientquit = 1;
int clientSocket,Replace the application-specific code toward the end of client.c with the following
/*
* Client application specific code goes here
* e.g. receive messages from server, respond, etc.
*/
while (serverquit != 0 && clientquit != 0)
{
status = 0;
while (status == 0)
status = read(clientSocket, buffer, sizeof(buffer));
serverquit = strcmp(buffer, "q\n");
if (serverquit != 0)
{
printf("S: %s", buffer);
for (i = 0; i <= 255; i++) buffer[i] = 0;
printf("C: ");
fgets(buffer, 256, stdin);
clientquit = strcmp(buffer, "q\n");
write(clientSocket, buffer, strlen(buffer));
for (i = 0; i <= 255; i++) buffer[i] = 0;
}
}
printf("Goodbye\n");
close(clientSocket);
return 0;
}Recompile both server.c and client.c and you are ready to try it out. To simulate two computers on one, open two windows in X or use two different consoles (e.g. alt-1 and alt-2.) Start the server in one window using the command
server 1024and the client in the other using the command
client hostname 1024where hostname is replaced by your actual hostname or IP address.
Server and client code for this chat program are almost identical, and very similar to the previous example. There are two main differences. The first is the test to see whether either party has entered a "q" to quit. The flags serverquit and clientquit signal this. The second is the tight loop waiting for response from the other party. The function read returns the number of character read from the socket; this is stored into status. A non-zero number of characters indicates the other side has sent a message.
Here is an example session as printed by the server:
Connection request from 192.168.1.1 Send q to quit. C: Hi server S: Hi client C: Bye server S: Bye client GoodbyeAnd here is the same session as printed by the client:
S: Hi, 192.168.1.1 S: Please start chat. Send q to quit. C: Hi server S: Hi client C: Bye server S: Bye client C: q GoodbyeI hope these examples have shown how easy it is to set up client/server computing. May your appetite be whetted to try your own applications. If you cook up something tasty, let the rest of us know. And don't forget to keep that string taut!
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© 1998 by |
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muse:
 elcome to the Graphics Muse! Why a "muse"? Well, except for the sisters aspect, the above definitions are pretty much the way I'd describe my own interest in computer graphics: it keeps me deep in thought and it is a daily source of inspiration.
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his column is dedicated to the use, creation, distribution, and discussion of computer graphics tools for Linux systems.
Wow, what a month. Since I'd finished working on my Gimp book in July and early August, I had all of September to work on my Muse column. Its been quite some time since I've been able to devote this much time to the Muse. I managed to keep up to date on all the product announcements made over on Slashdot, freshmeat, and on comp.os.linus.announce. And there were a ton of them. So many, in fact, I considered leaving some out just to keep this page from being too large. But that didn't seem right, so this month the Muse is a big, big column.
What we've got this month for you:
You may also want to take a look at the new and improved Graphics Muse Website. I've complete revamped the site. The old Linux Graphics mini-Howto and Unix Graphics Utilities pages are no more - they've been replaced by a searchable database of graphics tools, texts, news stories, and reviews. No more frames either, at least not in the Linux specific sections (my bio page still uses them, however). Its not as nice as Slashdot or Freshmeat, but its better than the static frame-based pages I had before. Hopefully, everyone will find these updates to their liking. It should certainly make finding tools a little easier. At least that was the plan when I started on it.
For those who don't want to see the new graphics in my portal pages, you can jump straight to the Linux specific section. But take a look at the graphics in the portals some time. I really kind of like them.
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imwheel 0.7Imwheel makes the wheel of your Intellimouse (and other wheel mice) work in Linux/X11 to scroll windows up and down, or send keys to programs. It runs in the background as a daemon and requires little reconfiguration of the XFree86 setup. 4 or more button mice and Alps Glidepad 'Taps' may also be used.http://solaris1.mysolution.com/~jcatki/ imwheel/ WorldEd 0.2.0WorldEd is a 3d modeller for KDE. It has a grid, a tree view, a 3d view, a Layout manager, and a Modeller. It will have full texture mapping, skeletal modelling, more heirarchal model design, 3dfx dual-screen support and other goodies. Development urgently needs additional contributors.New in version 0.2.0 is autoconf/automake support, seperate Modeller and Layout views, support for Lightwave/Blender ASCII imports, object rotation/scaling and updated screenshots. http://www.geocities.com/ Pentagon/Quarters/2865/ Red Hat to Release NeoMagic sourceSlashdot reports that Red Hat will release the source for the X Binary Free NeoMagic server after having received permission to do so from NeoMagic. This X server source includes support for NeoMagic's MagicGraph128 family of integrated single-chip graphics hardware. The full announcement from Red Hat can be found athttp://slashdot.org/articles/98/09/21/1626214.shtml |
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3dom snapshot 980910 (or later)3dom stands for 3-Dimensional Object Modeler. The aim of 3dom is to offer a tool to model reality with user-chosen accuracy, and user-chosen inclination for a particular purpose, which can be gradually improved and extended. 3dom is designed to be a general-purpose modeler, however it is especially inclined to model scenes for Global Illumination purposes.This release features better Renderpark integration, some new concepts, various bugfixes and enhancements. http://www.gv.kotnet.org/~kdf/3dom/ Linux Quake HOWTO 1.0.1.12The Linux Quake Howto explains how to install, run and troubleshoot Quake, QuakeWorld, and Quake II on an Intel Linux system.This version includes updated QuakeWorld install information for the new 2.30 release, info on using the new 3Dfx GL miniport with regular Quake and Quake2, more help on making Quake behave on glibc systems, and lots more. http://webpages.mr.net/bobz/ Other Announcements: Simple Direct Media (SDL) Logo contest New Version of Quake 2 is out. |
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aKtion! 0.2.0 and KXAnimaKtion! is a video player based on xanim. It (xanim) supports many different file formats like FLI animations, FLC animations, IFF animations, GIF87a and GIF89a files, GIF89a animation extensions, DL animations, Amiga MovieSetter animations, Utah Raster Toolkit RLE images and animations, AVI animations, Quicktime Animations and SGI Movie Format files.NOTE: You'll need to have xanim 2.70.7.0 properly installed in your machine to run aKtion!. KXAnim is a C++ widget wrapper around xanim to allow video playing in your apps. Both of these appear to be KDE applications, although they don't specifically state that on the Web site. aKtion! and KXAnim - http://www.geocities.com/ SiliconValley/Haven/3864/aktion.html Prometheus Truecolour 2.0.8Prometheus Truecolour (PTC) 2.0 C++/Java is the library of choice for demo programming. It allows you to render into an offscreen surface of your choice and then converts it on the fly to whatever video mode is available on the host machine. And it is designed to be small so it can be statically linked into your application.Version 2.0 of the library is currently under heavy development and updated nearly daily. A final release has been scheduled at around the end of August 1998. PTC 2.x is free software under the terms of the GNU Library General Public License (LGPL) http://www.cs.ucl.ac.uk/students/ c.nentwich/ptc/ PyroTechnics 1.2PyroTechnics is an OpenGL-based firework simulator. Features include multiple kinds of fireworks, the ability to choreograph firework displays, a texture-mapped water surface, reflections, a moving camera, and the ability to save screenshots.This version updates v1.0 with bugfixes, portability fixes, and the addition of command-line arguments. http://www.ling.ed.ac.uk/~oliphant/pyro/ k3de 0.0.6k3de is a 3D editor for the K Desktop Environment which generates sources for POVray.ftp://ftp.kde.org/pub/kde/ unstable/apps/graphics/k3de-0.0.6.tgz Quick Image Viewer 0.5Quick Image Viewer (qiv) is a very small and pretty fast GDK/Imlib image viewer. http://www.idnet.de/~AdamK/FxEngine 0.31FxEngine is a 3d graphics library that uses the glide API. It was made by Andreas Ingo and ported to Linux by Michael Pugliese. It is very powerful and easy to use. http://welcome.to/3dfxPS/Editor 's Note: watch out for bright red background - eek! |
ElectricEyes 0.2ElectricEyes is a lightweight GTK+/GNOME-based image viewer. It allows you to view and do simple manipulate of several image formats and gives a nice thumbnail selection mechanism.http://www.labs.redhat.com/ee.shtml fltk beta-19980825fltk (pronounced "fulltick") is a GPL'd C++ user interface toolkit for X and OpenGL (it has also been ported to windows). Fltk is deliberately designed to be small, so that you can statically link it with your applications and not worry about installation problems. As a side effect it is also extremely fast.This beta includes slight layout modifications, ports to Cray and other 64 bit machines as well as lots of bug fixes and small additions from users. http://www.cinenet.net/ users/spitzak/fltk/ VMD 1.2VMD is designed for the visualization and analysis of biological systems such as proteins, nucleic acids, lipid bilayer assemblies, etc. It may be used to view more general molecules, as VMD can read standard Protein Data Bank (PDB) files and display the contained structure. VMD provides a wide variety of methods for rendering and coloring a molecule: simple points and lines, CPK spheres and cylinders, licorice bonds, backbone tubes and ribbons, cartoon drawings, and others. VMD can be used to animate and analyze the trajectory of a molecular dynamics (MD) simulation. In particular, VMD can act as a graphical front end for an external MD program by displaying and animating a molecule undergoing simulation on a remote computer.http://www.ks.uiuc.edu/ Research/vmd/ XawTV 2.25XawTV is a simple Xaw-based TV program which uses the bttv driver or video4linux. It contains various command-line utilities for grabbing images and avi movies, for tuning in TV stations, etc. A grabber driver for vic and a radio application (needs KDE) for the boards with radio support are included as well.Recent releases include updates to work with version 0.5.14 of the bttv driver and adds a command line tool for recording avi movies plus an ncurses based radio application and driver bugfixes. If you don't get a picture with version 2.24, check out this version. http://user.cs.tu-berlin.de/~kraxel/ linux/#xawtv MagicianMagician is a commercial OpenGL implementation for Java. Portable to Unix systems, but its unclear if it runs on Linux or not.http://www.arcana.co.uk/ products/magician/ |
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gifc is a Perl script that requiresPerl version 5.003, patchlevel 23 (preferably 5.004). It also needs the GD Perl module which can be downloaded at http://www.perl.com/CPAN. Although the current version of gifc is 2.5, this is the first public release,. It has been tested on Linux 2.0 and HP-UX 10.20. The home page of gifc is: http://www.club.innet.be/~pub01180/gifctxt.html, from which you can also download the package. The program is released under the GPL. The README file contains build and installation instructions.
The author, Peter Verthez, can be reached for suggestions and bug reports at
http://hawk.ise.chuo-u.ac.jp/student/person/tshiozak/x-tt/index-eng.html - English version of web site
http://hawk.ise.chuo-u.ac.jp/student/person/tshiozak/x-tt/index-jap.html - Japanese version of web site
Editors Note: I think this is not really an X server but rather serves as an embeddable library for X servers or as a stand alone font server. Check the web pages for more detailed information.
Additionally, another update supports the Fujitsu Lifebook 990Tx2 using the ATI Rage LT Pro chip. If using Accelerated-X Laptop Display Server version 4.1.2, apply the update from URL ftp://ftp.xig.com/pub/updates/accelx/laptop/4.1.2/L4102.003.tar.gz . A description of the process to add the update is in the same directory, URL ftp://ftp.xig.com/pub/updates/accelx/laptop/4.1.2/L4102.003.txt .
Detailed results from benchmarking should be available on the Xi Graphics Web Site, URL http://www.xig.com/ , soon. The summary of the Xmark'93 single figure benchmark results for these machines are:
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SciTech is looking for all types of Linux users to help us stress test the utility before its final release. If you would like to participate in a beta, please contact or visit the SciTech Web site at http://www.scitechsoft.com.
Editors Note: a form for registering to participate in the beta release program accompanied this announcement in comp.os.linux.announce, however I felt it was a bit too large for inclusion here. The form doesn't appear to be on their web site, so you'll probably need to send email to the above contact address to request a copy of the form. Also, this program may have already expired by the time this column reaches you. Display Doctor may already be released for Linux by that time.
http://www.ling.ed.ac.uk/%7Eoliphant/glmame/
Crystal Space 0.11Crystal Space is a free and portable 6DOF 3D engine based on the portal technology. Latest version supports colored lights, mirrors, transparent textures, reflecting surfaces,optional BSP trees, 3D triangle mesh sprites (limited currently), mipmapping, scripting language, static shadows, dynamic lights (but with no shadows), ...http://crystal.linuxgames.com/ GdkRgb 0.0.7GdkRgb is a rewrite of the image rendering subsystem of Gtk+. Advantages over plain Gtk+ 1.0.x include higher speed, very smooth and pretty dithered modes, and support for more displays and visuals. It is currently checked into development versions of Gtk+ (and used in the development tree of the Gimp), but is also packaged separately for application authors who want to maintain Gtk 1.0.x compatibility. The programming interface is quite simple.http://www.levien.com/gdkrgb/ Blender 1.37Being the in-house software of a high quality animation studio, Blender has proven to be an extremely fast and versatile design instrument. The software has a personal touch, offering a unique approach to the world of Three Dimensions. Use Blender to create TV commercials, to make technical visualizations, business graphics, to do some morphing, or design user interfaces. You can easy build and manage complex environments. The renderer is versatile and extremely fast. All basic animation principles (curves & keys) are well implemented.Version 1.37 adds UV Mapping for NURBS as well as bug fixes.
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kvideogen 1.1KVideoGen allows for easy generation of Modelines, as used by XFree86 to determine your refresh rate, resolution etc. It will allow you to use higher refresh rates, and different resolutions to the 'standard' ones offered by the usual X setup utilities. Note: Read the docs on the website. This program can damage your hardware. Handle with care.http://www.rikkus.demon.co.uk/ PhotoShow 0.1PhotoShow is a simple Perl script that allows viewing, zooming, and adjustment (brightness/contrast/gamma) of images. It also has slideshow capability and is amazingly fast thanks to Imlib.http://www.verinet.com/~devious/ PhotoShow.html WebGFX - A New Gimp-based NetFu SiteThis is a very nice Net-Fu site. The design is quite artistic although the options available for logo generation from Log-O-Mat are a little limited (no foreground/background color, pattern or gradient specifications permitted). The Try-O-Mat is more configurable. The difference is probably due mostly to the limitations in the generic logo Script-Fu scripts that the site is using.http://www.webgfx.ch/ JMK-X11-FontsThe jmk-x11-fonts package contains character-cell fonts for use with the X Window System. The current font included in this package is NouveauGothic, a pleasantly legible variation on the standard fixed fonts that accompany most distributions of the X Window System. It comes in both normal and bold weights in small, medium, large, and extra-large sizes. Currently only ISO-8859-1 encoding is available.http://www.ntrnet.net/~jmknoble/ fonts/jmk-x11-fonts |
Additionally, to complement xfsft, another a small tool that automatically creates a fonts.dir file for TrueType fonts. It is available from http://www.darmstadt.gmd.de/~pommnitz/ttmkfdir.tar.gz. The distribution package contains a ttmkfdir binary for Linux/glibc2 (Intel).
MpegTV Player is now able to stream MPEG's directly from a URL, and HTTP/FTP support has been added
http://www.mpegtv.com/download.html
Did You Know?...A new objects collection, called simply "POV Objects", is now available for POV-Ray users. See http://povobjects.fsn.net/ |
New Gimp Plug-Ins announced this past month:
I have the pleasure of announcing a new plug-in for the GIMP. It called 'cam' and allows the GIMP to read CAM files directly. Those files are the ones stores in Casio QV-* digital cameras, that you can dump using QVplay for instance. I am afraid this plug-in is of no use for people who do not possess one of those little toys, though. URL: http://www.mygale.org/~jbn/qv.html wind - similar to what comes with Photoshop jigsaw - as in puzzle diff - produces an output image based on it's two input images duplicate - just a quick way to copy an image and all it's layers Screenshots and more info as well as source are available at: Nigel Wetten <http://www.cs.nwu.edu/~nigel/gimp/shack.html> More Did You Know... ...Issue #37 of Design Graphics has explanation of high-end graphics boards and AGP vs. PCI on pg 67. Very good article. |
A: Yes. Use the ASCII 2 Image script:
Q: A Gimp-User mailing list member asked - A few months back someone posted a method (maybe a script) for making text look like it was dripping, as if it had just been painted on and the paint.
A: Alan F. Ho responded: Perhaps the page you are thinking of is: http://www.gimp.org/tut-disp2.html. It's a great tutorial, though I can't seem to make my drippy text quite as nice as JTL's.
Q: Also, if there anyone knows of more "tips" type pages beyond the links on the Gimp page, could you let me know as well.
A: Here are a few:
Thanks to Alan for this information.
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contacted the IRTC Administrators with the following email:
If this is of possible interest to you, please get in touch with me. The appropriate blurb on Magician is at:
And his reply to me follows:
It runs pretty fast even though it's using the slightly slow Mesa OpenGL-a-like implementation and supports hardware acceleration where Mesa supports it, typically on Voodoo Graphics accelerators.
wrote:
The links are in the section of the column titled Did You Know?.
Andrew Kuchling <> suggested this:
...
image = self.camera.snap()
image = image.resize( (self.image_width, self.image_height) )
# Convert from 24-bit colour to an 8-bit palette
image = image.convert( 'P' )
# The quality factor ranges from 0 to 100, with the default being
# 75. The documentation for libjpeg says that 95 is about
# as high as you want to go; higher values increase the
# image size but don't affect quality significantly.
image.save( 'foo.jpg', 'JPEG', quality=95)
However, I'll put it on my list of things to do. If you'd like to write a review for this package and have it included in the Graphics Muse column (with full credit to you, of course) feel free to send it my way. I'll make sure it gets included (I may edit it a little to make sure it reads well, but thats about it).
Michal Jaegermann <> wrote to take a minor issue with last months Perl advice in the Muse:
Nobody will run you out of town for an excessive use of punctuation in a Perl code - if these are your private kinks. But claims in a widely published material that one should do that, instead of presenting this as an unhealthy personal habit, is a totally different matter.
However, I would like to address a few points about your reply. First, I don't have the perl documentation installed. I did install Perl 5 binaries at one point, but I don't (currently) run Perl at home - I run it on my Web server, whose Perl installation is handled by the commercial Web server provider (vservers.com). I ran "man perlstyle" but it died trying to display the page for unknown reasons. Same thing with any of the man pages I tried for Perl on that system. So my sources at the time the article was written were the two documents I listed: Programming Perl by Wall & Schwartz and the Official Guide to Programming with CGI.pm by Stein. The former is where I got the information about using ampersands for subroutines. Perhaps this is an outdated document - although I had just purchased it from Borders Books, its print date appears to be 1992! Still, its all I had. Yes, the Perl archives have documenation too, but I also have deadlines. The problem with writing articles (I've slowly discovered) is choosing between reaching a certain level of expertise and actually getting something out to my readers. In this case, I just happened to be working with Perl, so thats how I chose to write about Perl. In fact, its pretty much how every months articles get written. Whatever I happened to be working on that month. But it limits how much of an expert I can become before I have to start writing. Its not a very good excuse, but it is the reality of trying to do this column. Writing is much more work than I had expected.
But, "unhealthy"? Hmmm. The excessive use of ampersands doesn't seem to have affected my current bench press max....
Douglass Turner <> wrote:
I've recently started reading you "Graphics Muse" column. Lots of good stuff. I'm a 3D graphics guy and I'm looking for code to read/write 3D models into/outof the rendering system I wrote. Have you any idea where I should be looking?'Muse: Take a look at Keith Rule's text 3D Graphic File Formats: A Programmers Reference. This is not a Unix package/text, but he has source code for reading and writing many file formats. He says in the book (last time I read it, which was some time back) that it hasn't been ported to Unix but he doesn't know why it wouldn't port easily. You can find a little more info on the text on his Web site.
Where do you get it?
VisualDHTML, which I'll shorten to VDHTML for this article, is a actually a tool written in entirely in DHTML. It is available from Netscape's Web site. Since it is written in a form of HTML you can actually run it across the network, but you may find it more convenient to download the complete package from their web site to your local hard disk. In the tests I ran I found that the performance was significantly better running locally.
The download page for VDHTML is the same as the index page in the package you download. The download file is a zip file which you can save to any local directory. Use the Linux (or equivalent) "unzip" command to unpackage the files, which will be placed in a newly created directory called "visual".
The only prerequsite for running VDHTML is that you have a browser that supports JavaScript 1.2. That fairly well eliminates all browsers except Netscape Communicator 4.06 or the latest 4.5 beta releases of Communicator. If you don't have one of these, you may want to skip the rest of this article. Also, although you are supposed to be able to run this on your local system, attempting to run the application without being connected to the Net or by using local URL's seemed to cause unexpected behaviours: drag and drop no longer worked, widgets did not become visible in the preview window, etc. I suggest, during your experimentation, that you only run this early version while connected to the Net, if possible.
What does it look like?
Once you've unpacked the package you simply need to open the index.html file to get started. For example, if you unpacked the zip file in the /tmp directory you can type the following in the Location field of the Netscape browser:
file:/tmp/visual/index.htmlThe "file:" prefix is not actually necessary, but if you're unfamiliar with accessing files this way you might use it till you get used to where you're headed with this sort of URL. On the index page you'll find a link to Launch Visual DHTML. Just click on this and a small window will open announcing that the application is starting. For the sake of this article we'll refer to this window as the VDHTML Main Window. Once the page starts it looks pretty much like any other application. However, its really just another Web page! This is the first bit of magic to learning about DHTML. The pages they create can look like real applications. Note that the VDHTML page can take a while to load, even from a local hard drive.
Before we get too far I should note that VDHTML is relatively buggy at this point. If you use it just right it works fine, but straying from the straight and narrow (ie not using it just right) can cause Netscape to crash. I'll point out the caveats that I know about as I go.
 Figure 1 - The Visual DHTML Main Window |
 Figure 2 - Dialogs don't exist outside of the application window |
The Desktop option opens a window that will stay underneath all your other windows and acts like an interactive background image, except that its not "sticky", meaning it doesn't follow you around to other desktops (again, assuming you have a window manager like FVWM or CDE/mwm that allows multiple virtual desktops).
Once you've opened your New Window you are ready to start adding DHTML components to it. VDHTML comes with a set of predefined widgets that you can add to your page. Clicking on the Widgets icon in the menu bar of the Main Window will open the Widgets dialog (see Figure 3). Note that you may need to click and hold the left mouse button over the Widgets icon longer than you might normally in order to get the dialog to open. At least I did on my system. Also, when you click on a widget name in the dialog you need to hold the mouse button down until after the dialog is closed. Then release the mouse button. If you don't do it in this order the configurable parameters for the widget will not be shown and you won't get the widget in the preview window. Clicking in the Widgets dialog and releasing the mouse button before the dialog closes will simply close the dialog.
Ok, so you've got the Widgets dialog opened. Notice that the dialog is actually labeled "Components Palette" - a bit of inconsistancy from Netscape, but thats to be expected with any first release of a product. The available widgets are listed in a table, below a set of three options which act something like tabs in a notebook widget. The first tab is the widgets tab, which provides components like menus and buttons and clocks. The next tab is for setting specific HTML tags. The last tab is for setting link properties.
Bug: don't try to access the Tags option in the Widgets dialog without a preview window open. Doing so will crash netscape. In fact, the widgets dialog in general seems to cause Netscape crashes at random.
The available widgets include some unusual components, such as the drawer widget. This option creates what appears to be a small button that, when pressed, opens a drop down menu. This button can be placed anywhere in the page but seems to want to be anchored only to window edges. I'm not sure if thats intentional or a bug in VDHTML. Also, the default image for the drawer (the small button) can be changed to any image you want when you configure the widget. Figure 4 shows the configuration options for the drawer widget.
 Figure 4 - Configurable options for the Drawer Widget |
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One exception to dragging is the marquee widget. This widget creates a window that drops down (or comes in from the sides or up from the bottom of the browser window) with an image or text, sort of like an animated menu. But you can't drag marquees in the preview window. You have to specify the direction from which the marquee will enter the browser when you create it by using the configurable options. Apparently the marquee will always be on the left side of the preview window but as always you can edit the source later to move it to another location and have it enter the browser appropriately from any point.
Bug: While experimenting with the various widgets I discovered that they often didn't perform as expected in the preview window. Sometimes I could open a drawer, for example, but not close it. Buttons would post a menu but then I couldn't clear it. Its clear that the widgets functionality and their interaction within the preview window are still to be worked out. With all widgets the VDHTML Main Window offers configurable parameters. The defaults for those options which require a URL point to Netscape's site. This isn't a problem but you should keep it in mind if you take the default option values. If you decide to use the defaults (remember: be online if you do so or VHDTML might crash Netscape!) you can edit the HTML document by hand later and use your own URLs. |
 Figure 5 - Default Marquee Widget |
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What is X Input?
To quote from the X Input Howto: The XInput extension is an extension to X to allow the use of input devices beyond the standard mouse and keyboard. The extension supports a wide range of devices, including graphics tablets, touch-screens, joysticks, and dial-boxes. The most common use is probably for graphics tablets.For many readers of the Muse, X Input is how you'll want to interface with the Gimp. Outside of the Gimp there are only a few other tools that currently make use of the X Input extension. However, as graphics tools on Linux mature, there will be a much greater need for these sorts of extra input devices. Later, after we cover some configuration and testing issues, we'll restrict our application discussion to the two tools you are most likely to use with X Input: Gimp and gsumi. What X servers support X Input? X Input is reported to be supported by all 3 of the major X server vendors: XFree86 (which includes SuSE since they work so closely in their X server development), Xi Graphics, and MetroLink. Xi Graphics sent me their latest server, 4.1.2, to try for this article. I also downloaded the 3.3.2 XF86_SVGA server for use with my Matrox Mystique. I neglected to contact MetroLink in time to ask for a copy of their server, unfortunately. An email I received from MetroLink back in March stated that their 4.3 server includes support for dynamically loadable X Input driver modules. This includes Elo Graphics, Carroll, Micro Touch and Lucas/Deeco touch screens. They also mentioned plans for support of Wacom tablets and 3D input devices such as the Space Orb but I don't know if this support has been released yet or not. I also don't have any information on how devices would be configured to work with their X Input drivers. In testing the two servers I did have, I was successful in getting only one of them to work, XFree86's XF86_SVGA server. I have to thank for his helpful hints and suggestions in getting that server up and running with X Input. Most of the information I'm going to provide came with clarifications from Owen. The Xi Graphics server does list X Input as a supported extension, both in the documentation and from the xdpyinfo program. However, there is no information available on how to get that extension to recognize and work with any particular devices. It may be possible to use the gxid daemon, a daemon program which comes with the Gtk+ source distribution, to work with this server but I was unsuccessful in doing so. I contacted Xi Graphics about this and the last I heard they are still looking into it. I haven't heard if they had any more success than I did. Since I was only able to get one server to work with X Input, the rest of this article will focus on that server. If I get feedback from any one, vendors or users, on getting the other two servers to work with X Input I'll write up an update here in the Muse. What devices are supported? The XFree86 support of X Input includes drivers for the following devices:
Requirements for making use of the XFree86 X Input support I have a Matrox Mystique card with 4Mb of memory which I've been using for about 2 years now. This card is still on the market and will cost you roughly $100US or less depending on where you purchase it. Along with this I'm using a Wacom PenPartner, a 4"x5" tablet that sells for about $79US. This is the low end tablet from Wacom. The Matrox card is supported by the XF86_SVGA server (see the Resources section at the end of this article). X Input support in XFree86 has been available in since the 3.3.1 release (at least, perhaps longer). Most Linux users will probably have either the 3.3.1 or the latest 3.3.2 servers if they use any distribution that is less than 2 years old. |
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Along with the servers you also need to make use of one or more loadable modules. If you are like me and use the PenPartner tablet then you need to make sure you have the 3.3.2 version of the xf86wacom.so module. The 3.3.1 version of this module does not support the PenPartner but should work fine for other Wacom tablets.
If you have the 3.3.1 version of XFree86, you can download the particular server you need and the X3323bin.tgz file, which contains the binary versions of the 3.3.2 modules (plus other tools). You can find links to these packages from the XFree86 web site. You might wonder if you can run your older 3.3.1 libraries with an the newer 3.3.2 servers and modules. The answer is yes, you can. You don't have to update all your libraries, development tools, and X applications (the tools under /usr/X11R6/bin) although you can if you want a full 3.3.2 update. Along with the server and modules there are a couple of other tools you'll want to make sure you have:
Configuring the X server and hardware In order to make use of the X Input extension you need to tell the X server about how you want it configured and what driver to load for the device you will be using. XFree86's configuration file, XF86Config, is located under the directory /etc/X11. Although you can use the graphical setup tool XF86Setup for most options, you can't use it to configure X Input. You'll need to edit the configuration file by hand. The first thing you need to know about is which modules you'll need. Under /usr/X11R6/lib/modules you will find the X Input modules. For Wacom tablets you'll be using the xf86Wacom.so module. Similarly, SummaGraphics tablet users will want to use the xf86Summa.so modules. There are also modules for Elo Graphics devices (xf86Elo.so) and joysticks (xf86Jstk.so). To configure the module for use with the server, edit the XF86Config file and add the following lines: Section "Module"
The text to add looks like the following: Section "Xinput"The 4 SubSections define different devices to X Input. You can see these listed (after you start the server) by running xsetpointer -l. I'm not completely certain why you have to have two entries for each device but assume that the first entry is used by applications and the other entry is used to allow the tablet pen to be used as your regular pointing device. <More> |
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Online Magazines and News sources C|Net Tech News Linux Weekly News Slashdot.org Amazon.com's Linux Book Section General Web Sites Some of the Mailing Lists and Newsgroups I keep an eye on and where I get much of the information in this column |
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| "I've found only two things that last 'til the end One is your heroes, the other's your friends." |
| -- Randy Travis/Don Schlitz |
Could it be that one of the reasons the Linux phenomena is so strong is that it fulfills the above? Quick, without thinking, name one or two people you really look up to. Chances are, since you're using Linux, the names of Torvalds, Raymond or Stallman may have flashed through your mind.
As members of the Linux community, we have heroes. We have people we can look up to. We have heroes we can look up to and still disagree with. Can we say the same of our physical communities, our companies, our nations?
And what of friends? Think about the mailing lists you belong to, the news groups you read, and the Linux users group you belong to - who do you turn to when you need advice about your latest upgrade?
Does commercial software and Microsoft give you the same feeling? Can they compete with the feeling you just had while thinking about what Linus has wrought and the last helpful Linux-related email you received?
Community! That's what this is really all about. It's about having the best operating system, and the best software and the best support. It's about having the best. Period. And we know the best is still to come.
The question is often asked, "Will Linux be able to defeat the marketing muscle of Microsoft?" We already know the answer. And the answer is being provided by the growing number of people who use Linux as an everyday solution to their own needs.
Will there be an 'office suite'? Probably. But that's not what brought us to Linux in the first place, is it? So, why are you here?
What makes Linux really special is the people you never hear about in the press. The people who patch software and give it back to the community - you all know someone who's done this, or helped you with a shell script, or guided you as you learned more about Linux. You also know someone who is maintaining a Linux site, writing a driver or volunteering in some way to bring Linux to fruition. Linux is what it is because thousands of people, every day, contribute in small ways to Linux's success.
Heroes help you see a goal worth attaining. Your friends help you get there. When someone new to Linux asks a question, what they are really asking for is a friend's advice. Be there for them.
So, the next time some one asks you why you are using Linux, smile and think, "That's how it goes, with heroes and friends."
Copyright ® 1998 by Ron Jenkins. This work is provided on an "as is" basis. The author provides no warranty whatsoever, either express or implied, regarding the work, including warranties with respect to its merchantability or fitness for any particular purpose.
The author welcomes corrections and suggestions. He can be reached by electronic mail at [email protected].
In this installment, I will cover the following topics:
While the steps needed to configure the X system are fairly standardized, due to some differences and peculiarities between the Slackware 3.5 and RedHat 5.1 versions of Linux, where necessary, I will distinguish between the steps to be taken to accomplish a given task on each distribution.
Unlike Windows based systems, the X windowing system is composed primarily of two separate and distinct components, the X Server, and the Window Manager.
The X Server is the interface between the hardware and the Window Manager. This is somewhat analogous, although not entirely, to the "video driver" in Windows. In addition to servicing hardware requests, it also performs several other important functions, such as managing all X connections to the machine, both local and remote.
One of the advantages of a Unix or Linux system is the fact that it was built from the ground up to be a multi-user system.
This gives a Unix or Linux system the ability to service, or "host" many users, both locally through the use of TTY connections or virtual terminals, or remotely through socket based communication using a variety of protocols.
For an overview of the concept of remote X sessions, see my article in the September Issue of the Linux Gazette.
It is important to note that the aforementioned X Server, as well as most of the functions it performs, occur in the background, and are functionally transparent to the end user. In short, it's a busy little beaver!
The second component of the X windowing system is the Window Manager. This is the element of the X system that comprises the portion of the Graphical User Interface that you interact with. The Window Manager is responsible for the look and feel of your desktop; as well the front-end interface to the commands and programs you run.
There are many Window Managers available for Linux, and each person will have their favorite. It will be up to you to decide which one best fits your needs and preferences.
Since both distributions default to FVWM95, I will confine myself to this Window Manager for the purposes of this introductory document. For further information on some of the many other Window Managers available, consult the resources section.
At this time, XFree86 3.3.2 supports the following chipsets:
Ark Logic
ARK1000PV, ARK1000VL, ARK2000PV, ARK2000MT
Alliance
AP6422, AT24
ATI
18800, 18800-1, 28800-2, 28800-4, 28800-5, 28800-6, 68800-3, 68800-6, 68800AX, 68800LX, 88800GX-C, 88800GX-D, 88800GX-E, 88800GX-F, 88800CX, 264CT, 264ET, 264VT, 264GT, 264VT-B, 264VT3, 264GT-B, 264GT3 (this list includes the Mach8, Mach32, Mach64, 3D Rage, 3D Rage II and 3D Rage Pro)
Avance Logic
ALG2101, ALG2228, ALG2301, ALG2302, ALG2308, ALG2401
Chips & Technologies
65520, 65530, 65540, 65545, 65520, 65530, 65540, 65545, 65546, 65548, 65550, 65554, 65555, 68554, 64200, 64300
Cirrus Logic
CLGD5420, CLGD5422, CLGD5424, CLGD5426, CLGD5428, CLGD5429, CLGD5430, CLGD5434, CLGD5436, CLGD5440, CLGD5446, CLGD5462, CLGD5464, CLGD5465, CLGD5480, CLGD6205, CLGD6215, CLGD6225, CLGD6235, CLGD6410, CLGD6412, CLGD6420, CLGD6440, CLGD7541(*), CLGD7543(*), CLGD7548(*), CLGD7555(*)
Digital Equipment Corporation
TGA
Compaq
AVGA
Genoa
GVGA
IBM
8514/A (and true clones), XGA-2
IIT
AGX-014, AGX-015, AGX-016
Matrox
MGA2064W (Millennium), MGA1064SG (Mystique and Mystique 220), MGA2164W (Millennium II PCI and AGP)
MX
MX68000(*), MX680010(*)
NCR
77C22(*), 77C22E(*), 77C22E+(*)
Number Nine
I128 (series I and II), Revolution 3D (T2R)
NVidia/SGS Thomson
NV1, STG2000, RIVA128
OAK
OTI067, OTI077, OTI087
RealTek
RTG3106(*)
S3
86C911, 86C924, 86C801, 86C805, 86C805i, 86C928, 86C864, 86C964, 86C732, 86C764, 86C765, 86C767, 86C775, 86C785, 86C868, 86C968, 86C325, 86C357, 86C375, 86C375, 86C385, 86C988, 86CM65, 86C260
SiS
86C201, 86C202, 86C205
Tseng
ET3000, ET4000AX, ET4000/W32, ET4000/W32i, ET4000/W32p, ET6000, ET6100
Trident
TVGA8800CS, TVGA8900B, TVGA8900C, TVGA8900CL, TVGA9000, TVGA9000i, TVGA9100B, TVGA9200CXR, Cyber9320(*), TVGA9400CXi, TVGA9420, TGUI9420DGi, TGUI9430DGi, TGUI9440AGi, TGUI9660XGi, TGUI9680, Pro- Vidia 9682, ProVidia 9685(*), Cyber 9382, Cyber 9385, Cyber 9388, 3DImage975(PCI), 3DImage985(AGP), Cyber 9397, Cyber 9520
Video 7/Headland Technologies
HT216-32(*)
Weitek
P9000
Western Digital/Paradise
PVGA1
Western Digital
WD90C00, WD90C10, WD90C11, WD90C24, WD90C24A, WD90C30, WD90C31, WD90C33
(*) Note, chips marked in this way have either limited support or the drivers for them are not actively maintained.
All of the above are supported in both 256 color, and some are supported in mono and 16-color modes, and some are supported an higher color depths.
Refer to the chipset-specific README files (currently for TGA, Matrox, Mach32, Mach64, NVidia, Oak, P9000, S3 (except ViRGE), S3 ViRGE, SiS, Video7, Western Digital, Tseng (W32), Tseng (all), AGX/XGA, ARK, ATI (SVGA server), Chips and Technologies, Cirrus, Trident) for more information about using those chipsets.
The monochrome server also supports generic VGA cards, using 64k of video mem- ory in a single bank, the Hercules monochrome card, the Hyundai HGC1280, Sigma LaserView, Visa and Apollo monochrome cards.
The VGA16 server supports memory banking with the ET4000, Trident, ATI, NCR, OAK and Cirrus 6420 chipsets allowing virtual display sizes up to about 1600x1200 (with 1MB of video memory). For other chipsets the display size is limited to approximately 800x600.
Notes: The Diamond SpeedStar 24 (and possibly some SpeedStar+) boards are NOT supported, even though they use the ET4000.
The Weitek 9100 and 9130 chipsets are not supported (these are used on the Dia- mond Viper Pro and Viper SE boards). Most other Diamond boards will work with this release of XFree86. Diamond is actively supporting The XFree86 Project, Inc.
3DLabs GLINT, Permedia and Permedia 2 support could unfortunately not be included in XFree86 3.3.2 since there are open issues regarding the documentation and whether or not they were provided to us under NDA.
(End excerpt from Xfree86 documentation.)
Monitors:
Hypothetically, any monitor you have the documentation for, that is capable of at least VGA or SVGA resolution, SHOULD be compatible. However, the following monitors are explicitly supported:
Slackware 3.5:
Standard VGA, 640x480 @ 60Hz Super VGA, 800x600 @ 56Hz
8514 Compatible, 1024x768 @ 87 Hz interlaced (no 800x600)
Super VGA, 1024x768 @ 87 Hz interlaced, 800x600 @ 56 Hz
Extended Super VGA, 800x600 @ 60 Hz, 640x480 @ 72Hz
Non-Interlaced SVGA 1024x768 @ 60 Hz, 800x600 @ 72 Hz
High Frequency SVGA, 1024x768 @ 70 Hz
Multi-Frequency that can do 1280x1024 @ 60 Hz
Multi-Frequency that can do 1280x1024 @ 74 Hz
Multi-Frequency that can do 1280x1024 @ 76 Hz
NOTE: There is also an option to explicitly specify the Horizontal and Vertical Sync rates for your monitor if you have them available.
Red Hat 5.1:
Custom Mode (see above description for information about standard modes, as well as suggestions for
acquiring information for your monitor if the documentation is not available.
Acer Acerview 11D, 33D/33DL, 34T/34TL
AOC-15
Apollo 1280x1024 @ 68Hz
Apollo 1280x1024 @ 70Hz
Axion CL-1566
CTX-1561
Chuntex CTX CPS-1560/LR
Compudyne KD-1500N
CrystalScan 1572FS
DEC PCXBV-KA/KB
Dell VS17
EIZO FlexScan 9080i, T660
ELSA GDM-17E40
ESCOM MONO-LCD-screen
Gateway 2000 CrystalScan 1776LE
Generic Monitor
Generic Multisync
HP 1280x1024 @ 72Hz
Highscreen LE 1024
Hitachi SuperScan 20S
Hyundai DeluxScan 14S, 15B, 15G, 15G+, 15 Pro, 17MB/17MS, 17B, 17B+, 17 Pro, hcm-421E
IBM 8507
IDEK Vision Master
Impression 7 Plus 7728D
Lite-On CM1414E
MAG DJ717, DX1495, DX1595, DX1795, Impression 17, MX15F
MegaImage 17
NEC MultiSync 2V, 3D, 3V, 3FGe, 3FGx, 4D, 4FG, 4FGe, 5FG, 5FGe, 5FGp, 6FG, 6FGp,
A500, A700, C400, C500, E500, E700, E1100, M500, M700, P750, P1150, XE15, XE17,
XE21, XP15, XP17, XP21, XV14, XV15, XV17, XV15+, XV17+
Nanao F340i-W, F550i, F550i-W
Nokia 445X, 447B
Optiquest Q41, Q51, Q53, Q71, Q100, V641, V655, V773, V775, V95, V115, V115T
Philips 7BM749, 1764DC
Princeton Graphics Systems Ultra 17
Quantex TE1564M Super View 1280
Relisys RE1564
Sampo alphascan-17
Samsung SyncMaster 15GLe, 15GLi, 15M, 17GLi, 17GLsi, 3, 3Ne, 500b/500Mb, 500s/500Ms,
500p/500Mp, 700b/700Mb, 700p/700Mp, 700s/700Ms
Samtron SC-428PS/PSL, SC-428PT/PTL, 5E/5ME, 5B/5MB, SC-528TXL, SC-528UXL, SC-
MDL, 7E/7ME/7B/7MB, SC-728FXL, SC-726GXL
Sony CPD-1430, CPD-15SX, CPD-100SF, CPD-200SF, CPD-300SF, CPD-100VS, CPD-
120VS, CPD-220VS
Sony Multiscan 100sf, 100sx, 200sf, 200sx, 15sf, 15sfII, 17se, 17seII
TARGA TM 1710 D
Tatung CM14UHE, CM14UHR, CMUHS
TAXAN 875
Unisys-19
ViewSonic 15ES, 15GA, 15GS, 17, 17PS, 17GA, 5e, 6, 7, E641, E655, EA771, G653, G771, G773,
GT770, GT775, P775, PT770, PT775, P810, P815, PT813, VP140
Mice (listed in order of appearance in the selection list, horizontally, from left to right.)
Microsoft Standard mouse
MouseSystems
MMSeries
Logitech
MouseMan
MMHitTab
GlidePoint
Intellimouse
ThinkingMouse
BusMouse
PS/2
Auto
IMPS/2
ThinkingMousePS/2
MouseManPS/2
GlidePointPS/2
NetMousePS/2
NetScrollPS/2
Another possible option is to consider purchasing a "commercial" X server. Two possible choices are:
MetroX http://www.metrolink.com/
XInside http://www.xinside.com/
These commercial servers often support a wider range of cards and monitors, due to the willingness of the developer of the X server software to abide by Non Disclosure Agreements required by some card manufacturers. In plain English, some card manufacturers refuse to work with the open source community. Something to consider the next time you get ready to purchase a video card.
Likewise, the generic VGA or SVGA monitors will usually at least get you up and running. However, as I have mentioned previously, DO NOT EXCEED THE CAPABILTIES OF YOUR CARD OR MONITOR! Otherwise, you may initiate what is called in the electronics world "a smoke test." This is a bad thing, and makes your house smell, as well as setting off your smoke detector.
If you do not have the documentation available, check the various docs in the /var/X11R6/lib/docs area, or search the Internet. Another possible option is to go directly to the manufacturer's website if available, and acquire the specifications there. A final option on some monitors, the synch rates is sometimes listed on the back along with the model number and other information.
Make sure, if at all possible, that your card and monitor are on the supported hardware list. This will save you a lot of grief and give you the best chance of success, as well as enabling you to take full advantage of the accelerated features of your video card.
At a bare minimum, you should have the following information available: Manufacturer, make and model of your video card: e.g. Matrox Millenium Amount of RAM resident on the video card: e.g. 8MB
Manufacturer, make and model of your monitor: e.g. Viewsonic 15E Horizontal synch rate of your monitor: e.g. 31.5-82.0 Vertical synch rate of your monitor: e.g. 40-100
A special note on mice: If at all possible, try to get a three-button mouse. X uses the middle button for some special functions. While it is possible to configure a two-button mouse to behave as a three-button mouse using an emulator that requires you to depress both buttons simultaneously to emulate the middle button, this feature is flaky at best on many mice and sometimes hard to master.
Note for PS/2 mice users: It has been reported that some users experience problems with the behavior of a PS/2 mouse under X. This is almost always due to the fact that the general-purpose mouse (gpm) program is being loaded at boot time, and for some reason, freaks out X.
Some have suggested adding a variety of switches or other parameters to the start up file that are purported to correct this problem. However, I have had limited success with these methods. Sometimes they will correct the problem, other times they will not.
What does work all the time is to comment out the start up of gpm at boot time.
On a Slackware machine, cd to /etc/rc.d/rc.local and place a pound sign (#) in front of the lines that look similar to the following:
# echo starting gpm # gpm /dev/mouse
Should you find the need to use gpm while in text mode, simply type gpm <return> and start it manually.
On a RedHat machine, from the command prompt, simply type setup <return>
You will be presented with a dialog box prompting you to select a configuration tool. Select ntsysv then
tab to the run button and press return.
Scroll down the dialog box until you see an entry for gpm. Highlight this entry and depress the spacebar to remove the asterix (*), then exit.
Just as Unix or Linux will not run on marginal hardware that may work with Windows, it may or may not run on marginal or clone-type video cards and monitors.
While it is possible to "hand tune" X to work with just about any video card and monitor, to do so is NOT RECOMMENDED. Diddling around with your clock settings, choosing a card or monitor "similar" to your equipment, or just picking horizontal and vertical synch rates at random can damage or destroy your video card or monitor. DON'T DO IT!
The optimal configuration, and the only one I can recommend, is to make sure your video card and monitor are explicitly listed and supported by X before trying to configure and run it. While I do offer some suggestions for people with unsupported hardware, there is no guarantee these suggestions will work, nor do I offer any assurance that they won't damage your equipment. Proceed at your own risk.
The method and program used to accomplish this task will depend on which flavor of Linux you are using.
NOTE: The instructions listed below assume you are using Xfree86 3.3.2-2. If you are using one of the commercial X servers, such as MetroX or XInside, your configuration methods may be different. Please consult the documentation that comes with your commercial product.
Slackware 3.5:
The X configuration program for Slackware 3.5 is called XF86Setup. To start the program, at the command prompt, simply type:
XF86Setup <return>
You will be presented with a dialog box prompting you to switch to graphics mode. Select OK.
After a moment, you will enter the XF86Setup screen. Along the top of the screen will be a series of buttons to configure the various components of the X windowing system. They will appear in a horizontal row in the following order:
Mouse Keyboard Card Monitor Modeselection Other
RedHat 5.1:
The X configuration program for RedHat Linux is called Xconfigurator. To start the program, at the command prompt, simply type:
Xconfigurator <return>
Press return to get past the welcome screen, then skip to the video card section.
Slackware 3.5:
This should already have been taken care of during installation. If you have something other than a three-button mouse, be sure to select the Emulate3Buttons option for maximum functionality under X.
The next option, Keyboard, should be already configured properly. Under normal circumstances, no adjustments should be required here.
RedHat 5.1:
This should already have been taken care of for you during installation. If not, break out of the Xconfigurator and run mouseconfig, then start over.
Slackware 3.5:
Select the card option from the menu at the top of your screen. Scroll down and select the appropriate video card for your system.
If necessary, you may also need to select the Detailed setup button to configure Chipset, RamDac, ClockChip, Device options, and the amount of video RAM on your card. Usually these options will be probed automatically. I only mention this so you can "tweak" the card if you are feeling brave.
RedHat 5.1:
The setup program will now autoprobe for your type and model of video card. On the plus side, this can simplify things, IF it properly identifies your card. On the minus side, if it does not, it does not offer you an alternative to manually choose the card. If your card is not properly identified, see the unsupported card section for some general suggestions on some things to try.
Slackware 3.5:
If you have the documentation available, you may enter the Horizontal and Vertical Synch rates manually in the input boxes, or alternately, you may choose one of the preset configurations in the scroll box.
It is almost always safe to choose either the Standard VGA or Super VGA option to start, then work up to the specific settings and color resolution you desire (subject to the limitations of your hardware.)
Lastly, select the Modeselection option, and choose your desired screen resolution and color depth. To begin with, less is better. Start with 640x480 @ 8bpp to start, then work your way up.
When you are finished with your configuration, select done from the bottom of the screen, and the setup program will attempt to start X with the configuration you have selected. If all goes well, you will be prompted to write the configuration to your XF86Config file and exit. If you have any problems, you will be prompted to try again until you have your configuration setup properly.
RedHat 5.1:
At the Monitor Setup dialog screen, scroll down and choose the appropriate monitor. If your monitor is not listed, choose generic or custom. If you choose custom, have your vertical sync rate and amount of video RAM handy, you will need them.
You will be presented with a dialog box that contains the same monitor choices listed in the Slackware section. After choosing a monitor, you will be prompted to select your vertical sync rate. Finally, you will be asked to specify the amount of video RAM present on your card.
After exiting the Xconfigurator program, you are ready to test your new configuration
Since X is infinitely configurable, and also stunningly cryptic at times, an in depth discussion of all the configuration options available under X is beyond the scope of this document. However, what follows are a few things you may be interested in.
A few words about the X desktop:
Stupid X Tricks:
If the X server refuses to start at all, pay close attention to the error messages that appear while the server errors out. Most frequently, this is an improperly configured monitor or card that causes the server to die. Check your configuration.
If the X server starts, but the screen exhibits an improper size, or excessive flickering, you probably need to adjust your horizontal or vertical sync rates.
If the screen appears to be unreadable, due to excessive lines or smearing of the pixels, check your card and monitor configurations.
Simply put, most problems can be traced back to an improper configuration of the card, the monitor, or both. This is why I strongly recommend making sure your hardware be explicitly supported, or using one of the "generic" configurations to start with.
Beyond this, check the documentation for specific card set problems, specific monitor problems, and other general troubleshooting procedures.
Another possible option is to troll the newsgroups for a similar problem, or post a brief description of the trouble you are having, and hopefully, someone with a similar problem they have solved before will get back to you.
If all else fails, drop me e-mail and I'll be glad to try to help.
I had originally planned to include the configuration of your basic networking setup into this installment as well, but as you can see, this is a real porker as it is. So look for the networking stuff in part three.
Access to an on-line dictionary has been possible for several years now due to the Webster TCPIP protocol. Webster is useful but the number of servers has been on the decline, and the protocol itself is limited by its dependence on a single dictionary database. Rik Faith, a programmer responsible for many of the essential-but-taken-for-granted Linux utilities, has created a new, more flexible protocol known as DICT. DICT is another TCPIP protocol (usable either over a network or on a local machine) which provides access to any number of dictionary databases. Local access is provided by a client program called dict which contacts the dictd server daemon. Dictd then searches the available databases and makes any hits available to dict, which pipes its output to the default pager on the local machine (usually either more, less, or most). Net access is available from several servers, including the home DICT site. Looking up words while on-line frees the user from needing to install and run the dictd and dict client and server programs (as well as having to make room for the bulky databases on a local disk), but if you have the disk space it's convenient to have the service available at any time.
The dictd and dict programs are licensed under the GPL, so naturally they are set up to use freely available word databases.
DICT is a typical Unix-style command-line set of programs. GUI-fans will regret the absence of a graphical interface, but the glass is really half-full. Due to the absence of oft-troublesome GUI toolkit dependencies, the source for the client and server programs should compile easily. Toolkits come and go, but applications written with a simple console interface can easily be adapted to whatever the future toolkit du jour might be. There are numerous programmers who lack the time or inclination to develop Linux utilities from scratch, but welcome the opportunity to write GUI front-ends to console programs (see the Word Inspector section below).
Compiling and installing dictd and dict isn't difficult, but to make use of them the word databases need to be downloaded and installed. Here is a list of the free databases which are currently available from the DICT FTP site:
All of these files and their indices will occupy about thirty-one megabytes of disk space, roughly the same amount as the WordNet dictionary files alone. The DICT data-files are compressed with a variant of gzip called dictzip, also written by Rik Faith. Dictzip adds extra header information to a compressed file which allows pseudo-random access to the file. When the dictd server processes a request for a word it looks first in the various index files. These files (which are human-readable) are just simple lists with the location of each word within the compressed dictionary file. Dictd is able to use this information to uncompress just the single 64-kb. block of data which contains the word-entry. This greatly speeds up access, as the entire dictionary file doesn't need to be uncompressed and subsequently re-compressed for each transaction. Files compressed with dictzip can be recognized by the *.dz suffix.
Although dictzip doesn't compress quite as tightly as gzip, the added advantage of the header information (at least for the sort of access dictd needs) is a compensation. The above-listed dictionary files would need nearly seventy-five megabytes of disk space if they weren't compressed.
In issue 27 of the Gazette, (April, 1998) I wrote about another dictionary-database system called WordNet. In order to access a DICT database the dict server must be running which communicates with dict client programs, whereas WordNet isn't a client-server program; the small wn program searches the database indices directly. The upshot is that WordNet uses less memory than a DICT system, but since WordNet databases aren't compressed they occupy more disk space than the specially compressed DICT files. DICT files contain more words (along with etymologies, which WordNet lacks) and can be supplemented with new files in the future, but DICT lacks WordNet's powerful thesaurus and lexical usage capabilities. Another factor to consider is that development of WordNet has ceased, whereas DICT is still being improved and the chances of its continued development seem likely. Additionally, DICT can use the WordNet data-files in a compressed format.
Sample configuration files are included with the DICT distribution. The file /etc/dictd.conf should contain the location of your local dictionary files in this format:
database web1913 { data "/mt/dict/web1913.dict.dz"
index "/mt/dict/web1913.index" }
database jargon { data "/mt/dict/jargon.dict.dz"
index "/mt/dict/jargon.index" }
The dict client needs to know where the server is; if a local server is used a simple ~/.dictrc file containing this line will work:
server localhost
If both ~.dictrc and /etc/dict.conf are missing the dict client program will first attempt to access the www.dict.org web-server; if that fails it will try some alternate sites. To prevent these attempts (when running a local dictd server) just use the above ~/.dictrc file.
Dictd might not be a service which you would want to run all of the time. Though not a large executable, it uses a significant amount of memory, typically four to five megabytes. I surmise that the daemon reads the dictionary index-files into memory when it starts up and keeps them there. This premise also would explain why the word look-ups are so speedy. Memory access is much faster than disk access, and once the daemon determines from the index which sixty-four kilobyte block holds the desired information it can quickly decompress that small chunk of the dictionary file and serve up the word information. I've found that starting dictd while writing or whenever I become curious about word-usage and killing the daemon at other times works well.
Scott W. Gifford has written a nice graphical front-end to the dict client program called Word Inspector. Here's a screenshot of the initial window:
And here is one showing the output window:
In the README file accompanying Word Inspector Scott Gifford suggests setting up the application with several different window-manager menu-items. Running wordinspect --define --clipboard will bring up a Word Inspector output window (as shown in the second screenshot) with the contents of the current X primary selection as the input. Alternatively, wordinspect --search --clipboard will cause the initial window to appear with the X primary selection already shown in the entry field, and running just plain wordinspect will bring up an empty initial window, so that a word can be typed in which isn't a mouse-selection. These three commands could be set up in a submenu stemming from a top-level Word Inspector menu-item.
Word Inspector makes good use of right-mouse-button pop-up menus. Right-clicking on any word in a definition pops up a menu allowing you to either open a search (initial) window with the selected word already filled in, or open a definition window for the word. Highlighting a series of words with the mouse, then right-clicking, will enable the same behavior for phrases.
The source of the current version of Word Inspector is this web-site. The GTK toolkit is required for compilation, with version 1.06 recommended. Last modified: Mon 28 Sep 1998
Playing solitaire card games on a computer became popular when Microsoft bundled a Klondike game with Windows 3.1. Since then such programs have proliferated on nearly every platform which possesses a windowing interface. There is a certain appeal to dragging miniature representations of playing cards around the screen. A side benefit is that such games usually can keep track of scores, provide hints, and sometimes auto-play in demo mode.
There have been many solitaire games released for Linux. One of the older ones is xpat2, which has some of the nicest design-work of any of these games. Xpat2 shows its age due to the lack of card-dragging, which contributes greatly to the feel of a computer card-game. Clicking on a card instantly moves it to a legal destination; when there is more than one possible move, the one xpat2 chooses may not be the one you had in mind. Otherwise it's a fine game, with several solitaire variants to choose from and well-done on-line help.
Users of the GNOME and KDE desktop environments each have native solitaire games, both of which are quality applications. If you aren't a user of one of these desktop systems it's hardly worthwhile to keep the bulky shared libraries around just to play a simple game.
Recently I was browsing the incoming directory at the Sunsite FTP site; I happened across a small file which, according to its accompanying *.lsm file, purported to be an implementation of solitaire called Pysol written in the Python programming language. I was a little dubious of this claim. Python is a versatile and powerful interpreted programming language, but is it possible to write a card-game using Python which is as usable and pleasing to the eye as one written in C or C++?
It evidently is possible if the tkinter module is used to provide the graphical interface. Tkinter (which I assume stands for "interface to Tk") lets a Python script use John Ousterhout's versatile Tk toolkit to provide the windowing interface. Tk is normally used with the Tcl command language, but Tcl has several limitations. These have been sufficient to provide motivation for several replacements; Tkinter is widely used, but there are others. Perltk uses Larry Wall's Perl language as the command language; another is Stk, which uses Scheme as its scripting language. The Xxl spreadsheet is the first major project I've seen which uses this Tk/Scheme hybrid. (Perhaps I'll review Xxl one of these months).
Pysol was written by and he has released it under the GNU license. The game is an extensive reworking and enhancement of a simple Python solitaire demo written by Guido van Rossum (creator and maintainer of the Python language) which is included as an example in the Python distribution.
Here is a list of Pysol's features, adapted from the README file in the distribution:
Nine games can be played: Gypsy, Picture Gallery, Irmgard, 8X8, Freecell, Seahaven,Braid, Spider, and Forty Thieves. The rules and documentation are supplied in HTML format and are displayed in a separate window using a Python HTML extension. Card-dealing at the onset of a game is nicely animated, and the mouse-dragging of cards works smoothly.
If you have ever spent much time playing solitaire on a computer you probably have noticed that after a certain point in a game the outcome seems obvious. This intuition isn't always accurate when you suspect the game is lost, but sometimes it's obvious that several more card-moves will win the game. Pysol binds the a key so that, when pressed, it will automatically cycle through those moves and bring the game to completion. When you strongly suspect that the game can't be won, the menu-item Demo (in the Game menu) will ask if you want to abandon the current game; pressing the "Yes" button will start the demo mode and either finish the game or find that it can't be completed. I've found that about one-quarter of the times I resort to demo mode my intuition was wrong and the game could have been won. If a game is hopeless a pop-up window appears informing you that "This won't come out".
Pysol's help key is h; when it's pressed a black arrow appears extending from a card to a recommended destination. The same arrows appear when Demo mode is initiated, though in this case the cards are actually moved.
Here is a screenshot of a Pysol Klondike game:
Pysol won't work at all if you don't have a current Python installation, including the tkinter module. A current Linux distribution will include all the Python stuff you would ever want, it's just a matter of installing it. As far as that goes, Python is one of those high-quality applications which is very likely to compile well from source, assuming you have the basic Linux development packages installed, such as gcc, make, etc.
Pysol is just a 75-kilobyte executable Python script; running make install will copy the script to /usr/games and the necessary data-files to /usr/share/pysol, after which the game is ready to run.
I'm impressed by this game's quality and playability. It does take several seconds to start up, probably due to the necessity of loading the Python interpreter and the Tkinter module into memory.
Last modified: Mon 28 Sep 1998
Last month I discussed Simon Baldwin's lesson-based typing tutor, Typist. In response to that article sent me e-mail concerning another typing tutor commonly used on FreeBSD systems. With his permission, I'll quote from his message:
Dear Mr. Ayers:
In the Linux Gazette you recently expressed your interest in learning the Dvorak keyboard, and I thought you might enjoy playing with the attached Tk program called kp (=Keyboard Practice). It seems to be standard issue with FreeBSD, but I've never seen it in any Linux distribution or archive.
It was written for Tk4.1, but works perfectly well with 4.2. I haven't tried it with 8.0, though, so you might have to hunt up an older version of Tk, if you don't already have one. To set it up, either untar it in /usr/local/lib, or put everything into ~/bin, or whatever you like best. Then edit the "executable" kp file so that the first line corresponds with your version of wish (I have the 4.2 version in /usr/bin/wish4.2 on my Debian system), and the "cd" line points to /usr/local/lib/kp, $HOME/bin, or wherever you decided to plant the .tcl files. Copy kp to /usr/local/bin (or leave it in $HOME/bin, if that's in your path), fire up X, invoke "kp", and off you go!
In the "options" menu you can switch between Dvorak and qwerty, and in the "file" menu you can insert any ascii text file you wish as a model for practice. The filter allows you to limit the text to words composed of specific letters; swipe your finger over the keys in the home row, for example, and the filter will pull out only those words made up of the letters in the home row. Quite cleverly done.
If you decide that you want to use the Dvorak layout for Real Work(TM), it's quite easy to have xmodmap load a Dvorak keymap for you, and switch back to qwerty when you're done. Emacs can load a Dvorak keymap for you, too. And some clever soul came up with the idea of aliasing "asdf" to "xmodmap .kbd.dvorak" and "aoeu" (the same four keys!) to "xmodmap .kbd.default", so that your whole family doesn't have to suffer :-) , but can switch back to a "normal" layout with one simple key pattern. Presumably you could use the same trick to reset the keymapping in console mode, too.
The "clever soul" referred to above is Don Reed (according to a later message from John Chapman). Don Reed wrote an HTML file explaining his approach to switching keyboard layouts on the fly; John sent me the file, which you can read here.
Keyboard Practice is a useful and well-designed Tcl-Tk program; its ability to use any text file as practice material is a nice touch. It was written by Satoshi Asami <[email protected]>. It's not just for practicing Dvorak typing; a menu-item lets a user switch to QUERTY as well. Since the archived files occupy just a little over twelve kilobytes, you can access them in this issue of LG here. To try it out, just follow the instructions in the above quoted message from John Chapman.
John also suggested a reference to the Dvorak International Web-site, which (although not updated recently) has links to most Dvorak sites on the net.
I am a Mechanical Engineer and an owner of a small business, , specializing in mechanical design and drafting and project management of small to medium size projects in mechanical engineering field. As any small business owner knows, the cost of start-up can be quite high, especially in the field where high end workstation and 3-D software are very important. I knew that I couldn't afford the SGI(TM) or UltraSPARC2(TM) machine (even though that would have been perfect), so my options were down to which operating system I would be running my PC under.
I had two options:
Doing the preliminary cost estimate comparison between these two options, I quickly ruled out Windows(TM)-based system.
And so my search began for a production quality mechanical CAD system that would run under Linux, and be reasonably priced.
I have used Linux for three years, and all that time the available applications and their quality have constantly been improving. I have felt that the only field where Linux was thin in available applications was mechanical engineering. True, there have been some CAD apps out there, but they either required too much programming (very powerfull VARKON, for example) or were too simplistic for production drafting (otherwise very good xfig/transfig combo). I have also looked into Bentley's Microstation (TM)( for Linux, but they only offered educational licences at the time ( a move I will never understand: who would get an educational licence for a piece of software they can not continue using after graduation- at least not under the same OS-?). Just for the record, I think the Microstation(TM) could blow away anything offered for Linux in this field, if they had some management vision and interest in developing for Linux community. One other site is worth mentioning, if for nothing else but for more exposure of this project to other Linux users- FREEDraft project. It is an attempt to bring to life a GNU drafting package, and I wish those people the best of luck in future development.
Then I have noticed two new entries in the software arena, LinuxCAD and VariCAD. I have almost purchased LinuxCAD (at $75, it seemed like a great deal), but didn't like the fact they had no demo available, and their E-mail reply to my preliminary inquiry had amounted to a little more than self-promoting junk mail. Only a couple of days later there was a usenet discussion about LinuxCAD and result was a page posted here, which comletely turned me away from LinuxCAD. I went to VariCAD's USA site instead, and quickly found out there is a working demo (without Save features) available for a download.
If you are interested in doing a search for available apps for Linux on your own, I recommend following sites as a good starting point:
Download consisted of getting four tarred files, and amounted to about 5Mb, which is very reasonable for a CAD system, along with the installation script. Available for the download is also RPM package, which must be downloaded as a roughly 5Mb single file, and it represents a nice touch for people running Red Hat distribution of Linux.
Installation instructions, for people who choose to get the plain tarred files, are very simple and clearly stated at the download site. I have simply followed those instructions, and it worked like a charm with version 6.1. As of a Aug. 29 1998, they have released new version, 6.2-0.3, and in my experience, there is a small glitch in installation script inst.sh which requires one to log in as root for it to work. On my system trying to execute the inst.sh script under su did not work; only 'true' root login managed to install the program. Also, the tarred files had been deleted in the installation process, so if you want to have a backup on the floppies, be sure to copy tarred files someplace else first, before executing the inst.sh script. This didn't happen with the version 6.1, though. On the other hand, new version (6.2-0.3) seems to be more robust, and it adds a drop-down menu for Internet access, which I haven't tested yet.
Since I'm running the Debian distribution, I would have liked to see the option in the installation process for choosing the target directory, and would have rather placed the VariCAD under /usr/local tree than under the default /usr tree. On the other hand, after installation script had completed, executing varicad command for the very first time in the rxvt resulted in a flawless start. I'm running the Xfree86 windowing system, with xserver-mach64 running in the 1152x864 resolution and 32 bpp, and VariCAD didn't seem to have a problem with those settings. After I have been playing with the software for a week, I decided it was worth the price they are asking for it and, after I have mailed in the cheque, received a small file in an E-mail which enables the save feature. As per instructions in the E-mail I copied the file to the /usr/lib/Varicad tree and at the next start of the program, the pop-up message about demo nature of the program went away, and I could happily save files and settings
Before going any further, I would like to say that my exposure to AutoCAD (TM) has been limited to version 10, way, way back, and if you are expecting the direct comparison between Mechanical Desktop (TM) and VariCAD, I'm afraid you will be dissappointed. If you are using AutoCAD and have given VariCAD a try, please your short review in an HTML format, and I'll post it here or send me an URL pointer to your page.
Because VariCAD does not use the Motif libraries, the executable is rather small and efficient. Fired up and having a rather simple 2-D drawing running, VariCAD toll on the system's resources is rather small ( output from ps on my system running VariCAD):
~$ ps aux
USER PID %CPU %MEM SIZE RSS TTY STAT START TIME COMMAND
dnaden 2406 11.4 2.7 4844 1760 1 S 22:16 0:02 /usr/bin/varicad
The interface is very plain which is a plus in my opinion. Starting with ver. 6.2-0.3, the 'tool-tip' style description is available for all the buttons of the toolbar, which is a very important feature if you are just strarting to use the software. On-line manual is available from the drop-down menu, and it is very complete. Some parts suffer from less-than-optimum english translation, but I haven't found that to be in a way of getting the gist of the information through. Then again, my english is not perfect, either...
Sytem starts up in a 2-D mode, and switching into the 3-D mode is a matter of simple click on the icon in the top right-hand corner. Default toolbar features the icons for drafting functions, and paging through the toolbars for other functions ( dimensioning, for example) is done by clicking on the respective icon in the bottom part of the toolbar. All toolbars seem to be of the tear-off variety, but I haven't tested that extensively ( I like my interface clean). And all the functions are available through the drop-down menus as well.
First thing I have noticed is that panning and zooming back and forth is done fast. A simple subjective comparison between very similar machines running CADKEY (TM)for Windows(TM) v.7.5 (under WinNT(TM)) and VariCAD v6.2-0.3 under Debian/GNU Linux v.2.0 would suggest that VariCAD is slightly faster in redrawing the screen. Another feature I like is the way zooming and panning work (users of Pro/E should feel at home here): dragging the mouse ( and having the Shift+LMB pressed) up and down zooms in and out, respectively, and dragging the mouse, having the Control+LMB pressed, does the panning. It is very convenient feature when you get used to it. And if you get lost in all this zooming and panning, there is a feature called Aerial View, which brings up a small window with the overview of the entire drawing area and highlights the square you are in at that moment in the main window ( I believe I have seen same feature in AutoCAD Lite(TM)...). Other noticeable feature ( for me at least) enables one to highlight the feature when the mouse cursor is over it. If you ever worked with lots of lines spaced close to each other, you will learn to appreciate this. It can also highlight feature's significant points (i.e. end- or mid- point of the line, center of the circle and so on) by popping up a small code when your cursor is on top of it. I haven't had that in CADKEY(TM), so it will take me some time before I can remember all the symbols and their meaning, but AutoCAD(TM) users should be familiar with them ( for example, @ for the center of the circle...).
Otherwise, VariCAD seems to have all the drafting, geometric tolerancing and dimensioning functions one would expect to find in a decent CAD package. In addition to that, there is a macro language, which I haven't had a chance to try yet, rather complete 3-D kernel (see some screenshots from VariCAD's site) and ability to import DXF and IGES formats. I have imported a 1.2Mb DXF file from CADKEY(TM) without a lost line, but dimension text was angled, and it could not be edited. But, as I said, I used CADKEY (TM)to export the file, and therefore the file is being translated twice, and it is hard for me to determine which one is "wrong" translation. I haven't tried to optimize the translator in VariCAD either. Translation itself is transparent, which means that as soon as you read the DXF or IGS file, VariCAD produces its native (dwb) file on which you continue to work. To translate the file to DXF from within the VariCAD, just save the file with a DXF extension. As simple as that.
Developers have been smart enough to include in the "core" software a database of Parts, consisting of nuts, bolts, washers, pins and SKF bearings. Also a part of the package is a calculation program for calculating spur and straight bevel gears, splines, shafts, bearings and compression and extension springs, as well as the V-belt drives. ( I have probably missed some other elements in here. Check out their site for full description...) There is also a possibility of creating the information needed for making the BoMs, although I haven't touched that yet myself. I also haven't had the need to print anything as of yet; most of my jobs are being sent in a DXF format on a floppy.
The only gripe I have with the software is that I can't seem to be able to find out how to dimension to or from "imagined" intersection. I frequently need to use the dimension from this or that edge to the intersection of the chamfered or radiused corner, and I can not get VariCAD to recognize that I want to use the point where two lines would have intersected each other, had it not been for the radius for example, as one of the references for the dimension. If anyone knows how to do it, please let me know.
I have found people at VariCAD to be knowledgable and courteous. Everyone, from sales rep in Canada to their HQ in Checz Republic, had answered my e-mails within 24 hours. As an example: in the 6.1 version, there was a bug in vertical dimensioning when using the toleranced dimension (the dimension line would not break around the text, but go right through the text). I have written an E-mail about it to their tech support, and within 12 hours, I had an answer- they were aware of it, and it happened only in inch drawings, not in metric ones, and will fix it in upcoming 6.2 version. Fair enough, I thought... About a month later, on the very day of the new version release, I have received an E-mail (from the same tech support guy) notifiying me that the new version is available for download, and the bug I have asked about had been squashed. That is what I consider a good customer service.
In a couple ow weeks my mCAd page was up, I have already received a couple of E-mail responses from other VariCAD users. Thanks for your input. Keep it coming...
One user had a problem with too much mousing (not enough command line input) in the earlier (but don't know which) version of variCAD and didn't try it since. I know there is a command line input, but as I said, it is not straight *utoCAD copy, so some commands may need re-learning. And also the quality of the help files was questioned, but I maintain that is mainly a language barrier. We English speaking folks take the fact that everyone knows English too much for granted.
The other E-mail was regarding the inconsistent volume calculator. I can not attest or deny that, as I didn't use 3-D enough as of yet, and VariCAD allegedly claims they have had no such problems.
I get mail from folks about my book, the device driver I wrote for Linux, and about articles I've written for Linux Journal. A few months ago I got one which said, in part:
My boss is a great guy to work for ...[but he] is of the opinion that Linux is the work of ``college punks'' and will not consider it for serious work.
He had a nightmare with the MINIX file system and is permanently convinced that UNIX simply cannot be trusted and that Linux is the work of pimply-faced sophomores with time on their hands. I got a good laugh out of that while looking at your picture and reading your bio.I can only hope his laughter was kindly. The opinions expressed by his boss weren't the first I've heard of that sort. Nor, I fear, will this be the end of it. Nonetheless, I decided to take a shot at confronting these claims.
I had suspicions that Linux contributors are a bright, experienced and well-educated bunch of folks. The discussions in the various Linux newsgroups and mailing lists aren't lightweight, nor is the resulting operating system. My ``feel'' of the operating system is that it's based on a lot of mature judgments and there is some theoretical grounding in what's being done.
I gathered up a list of contributors (from /usr/src/linux/CREDITS) and sent off 241 notes. Partial text of this note follows:
I'm conducting a brief survey of fellow contributors to the Linux kernel. ...
It seems that products developed by students, no matter how well designed and implemented and no matter how qualified the students, are regarded as having lower quality. ...
But that's not really the case with Linux. Almost from the start it has been more than just a school project. ...
I'd like to investigate the educational backgrounds and current work situations of the contributors.I sent my notes with some trepidation--I didn't want to bother folks while they were working on important projects, and I feared a lack of response.
I needn't have worried. So far I've received 103 replies, many of which have included a few words of encouragement. It seems that I wasn't the only one who wanted to respond to unjustified complaints about Linux. (Another 29 notes were returned with address errors. I hope to see corrections to the CREDITS file.)
The level of response was the first piece of good news. The second was that I've been stunned by how strong the development team is with regards to both credentials and experience.
From these replies I found:
When I offered an earlier summary of these results, my correspondent reported that his boss wisely intoned, ``those folks are all academia and none of them have ever tried to run a business.''
I had sort of expected a comment along those lines and fortunately I had asked a few more questions in my survey. One hundred of the replies also reported the number of years spent programming or doing system design.
As I noted earlier, I have also felt that Linux has benefitted from a broad experience in its developer base. Linux may be a first operating system for a lucky few, but almost everyone (all but three) claimed to be at least a skilled user of another operating system. Eighty-three were skilled users of several other operating systems.
Nor was their contribution to the Linux kernel the first of that sort. Twenty have contributed to another operating system and another twenty-two have contributed to several other operating systems. One reported:
Speaking for myself, I had the same idea Linus did, but he beat me to it. (I've heard others say this as well.) I knew how to build a UNIX-like system from the ground up, and there was a need for it for PCs. (Vendors were charging exorbitant amounts for poor products in those days, and there was no good 32-bit development system for 386s.) I just didn't have the time. I had been playing with MINIX when Linus showed up on the MINIX newsgroups, and it took off from there. I can tell you that though I was a student at the time, I'd been a professional systems programmer for many years before. So, I and many others knew what professional quality software was, as well as how to produce it. I think it turned out pretty well.
Finally, I wanted to know if the contributors were ``doing Linux'' in their careers. Eighty-two said their current employment was based on their computer skills. It was interesting to note that over a third reported their current employment supported or relied on their Linux development efforts. Sadly, two reported they were currently unemployed, but one of those also noted that he was ``voluntarily unemployed to have time to put my life in better order.''
Perhaps one significant difference between Linux development and academic or commercial development is the duration of personal interest. In an academic setting, a student typically has one term, or at most one year, to work on any given program. When programmers leave a company, support is picked up by someone who has no sense of what has gone before. There is greater continuity in the Linux community because of the nature of submission and distribution. No matter what is happening at school or where one works day to day, contributors can keep in touch with progress on their piece of the puzzle. One person noted, ``Personally, I did start my code in school, but that does not stop me from maintaining it now.''
There are some other issues which weren't addressed by my survey. Although it might not seem relevant to quality and performance, a person's interest has a great deal to do with the outcome--it leads to a distinction between ``craftsmanship'' and ``work product''. Another person noted:
``Intent'' is what I think all of these debates are about. In the commercial world there is only one true answer to ``Why are you helping develop Linux?''--``To make a living.'' In the Linux community I'm quite certain the answer would be more closely aligned to ``For me to use.'' The Linux community tends to be self-driven and self-motivated, and that is what leads to the successes and the apparent failures in our development environment.
We are not a company; we don't have any one person, or group of people, setting the direction Linux will take. That direction is set by those with the energy to actually do something.Another motive, akin to what pushed me to first join the effort, was shared by another respondent who said, ``When I wrote [my code] for the Linux kernel I was working at [my former employer]. Linux use there was extensive, and I wanted to give something back.''
Motivation leads to the final, and most significant issue--one which cannot be examined by a developer survey.
In a world driven by marketing, image is the basis for purchasing decisions. Even if a good image could be established for Linux by listing credentials or tabulating years of experience, I'd be reluctant to shift to that level. I'd much rather see acceptance and popularity for Linux based on quality and performance.
Even though I hadn't asked specific questions on this topic, a few people offered comments. One note seemed to identify, however obliquely, on what may be the key to Linux's success.
In general, my experience is that most software I have seen which was developed by students is not of the professional quality I would like to see. On the other hand, much of the commercial software I have seen, which was developed by professional software development companies, is also not of the professional quality I would like to see. The difference is most people do not get to see the internals of commercial software.Developing on this theme, another wrote:
The reason Linux is stable and usable is not because of its student programmers [or lack thereof]. It is because of the overwhelming feedback that ALPHA and BETA testers provide. When you read the Linux kernel, you will find many parts are poorly structured, poorly written and poorly documented. However, people dared to test it and report their problems; Linus and friends respected the error reports and went ahead to fix them. That is why it works so well.
In addition, psychology sometimes causes weird effects. If a user discovers a bug in his system, reports the bug and sees it fixed eventually, that user is happy because he was treated with respect. Most likely, he is even happier than he would be in the bug-free case.We not only need to bring the CREDITS file into an accurate state, but we also need to acknowledge the thousands who have contributed to Linux by using it and sharing their discoveries--good or bad--with others.
Peter H. Salus reports the UNIX philosophy in A Quarter Century of UNIX as:
I just received a note from the person who sparked the original survey. He reports:
I took my ``hand-me-down'' Linux box, an unimpressive 75MHz Pentium with 64MB RAM and a tiny 600MB HD to work. My boss was amazed that office applications such as StarOffice were available and was quite impressed when I read a Word document with StarOffice and then converted it to HTML. Samba was another revelation. Overall performance impressed him. In a few crude tests, it outperformed a ``commercial'' system running with 128MB RAM, dual 200MHz processors and all ultra-fast/ultra-wide SCSI drives.
After a couple of callers indicated an interest in UNIX versions, we checked the price of current systems. My boss decided Linux was indeed priced right, and asked me to start on a port.It looks like we've won one more away from the dark side.
Linux kernel developers are self-reported in the file /usr/src/linux/CREDITS. If their names weren't entered there, I didn't find them. Furthermore, there are many more who contribute by testing various development releases and reporting on the problems. Sometimes they even report possible source code corrections, but they aren't included in the CREDITS file.
Linux consists of much more than just the kernel. There are a host of related programs, such as those which are broadly distributed by the Free Software Foundation for UNIX and other operating system users, and others which support only Linux.
It would take significant effort to identify all those who have contributed to make Linux a success. The Debian project reports who is working on that distribution, but that's not enough. I'd like to see a CREDITS file in every package and tar file. I'd appreciate hearing of efforts along this line.
Web application servers are an extremely useful extension of the basic web server concept. Instead of presenting fairly simple static pages or the results of database queries, a complex application can be made available for access across the network. One problem with serving applications is that processing on the back end may take a significant amount of time and server resources--leading to slow response times or failures due to memory limitations when multiple users submit requests simultaneously.
There are essentially three basic strategies for handling web requests which cannot be satisfied immediately: ignore the issue, use unbuffered no-parsed-header (NPH) CGI code to emit ``Processing'' while the back end completes, or issue an immediate response which refers the user to a result page created upon job completion. In my experience, the first option is not effective. Without feedback, users invariably resubmit their requests thinking there was a failure in the submission. The redundant requests will exacerbate the problem if they aren't eliminated. To make matters worse, the number of these redundant requests will peak precisely at peak usage times. NPH CGI is most useful when the processing times are short and the server can handle many simultaneous instances of the application. It has the drawback that users must sit and wait for the processing to complete and cannot quickly refer back to the page. My preferred method is referral to a dynamic page, combined with a reliable method of serializing requests.
As an example, I will describe my use of Generic NQS (GNQS) (see http://www.shef.ac.uk/~nqs/ and http://www.gnqs.org) to perform serialization and duplicate job elimination in a robust fashion for a set of web application servers at the University of Washington Genome Center. GNQS is an Open Source queueing package available for Linux as well as a large number of other UNIX platforms. It was written primarily to optimize utilization of supercomputers and large server farms, but it is also useful on single machines as well. It is currently maintained by Stuart Herbert ([email protected]).
At the genome center, we have developed a number of algorithms for the analysis of DNA sequence. Some of these algorithms are CPU- and memory-intensive and require access to large sequence databases. In addition to distributing the code, we have made several of these programs available via a web and e-mail server for scientists worldwide. Anyone with access to a browser can easily analyze their sequence without the need to have UNIX expertise on-site, and most importantly for our application, without maintaining a local copy of the database. Since the sequence databases are large and under continuing revision, maintaining copies can be a significant expense for small research institutions.
The site was initially implemented on a 200MHz Pentium pro with 128MB of memory, running Red Hat 4.2 and Apache, which was more than adequate for the bulk of the processing requests. Most submissions to our site could be processed in a few seconds, but when several large requests were made concurrently, response times became unacceptable. As the number of requests and data sizes increased, the server was frequently being overwhelmed. We considered reducing the maximum size problem that we would accept, but we knew that, as the Human Genome Project advanced, larger data sets would become increasingly common. After analyzing the usage logs, it became apparent that, during peak periods, people were submitting multiple copies of requests when the server didn't return results quickly. I was faced with this performance problem shortly after our web site went on-line.
Listing 1. Sample GNQS Commands
Instead of increasing the size of the web server, I felt that robust serialization would solve the problem. I installed GNQS version 3.50.2 on the server and wrote small extensions to the CGI scripts to queue the larger requests, instead of running them immediately. Instead of resorting to NPH CGI scripts which would lock up a user's web page for several minutes while the web server processed, I could write a temporary page containing a message that the server was still processing and instructions to reload the page later. By creating a name for the dynamic page from an md5 sum of the request parameters and data, I was able to completely eliminate the problem of multiple identical requests. Finally, all web requests were serialized in a single job queue, and an additional low priority queue was used for e-mail requests. It was a minor enhancement to allow requests submitted to the web server for responses via e-mail to simply be queued into the low priority e-mail queue. Consequently, processor utilization was increased and job contention was reduced.
While this proved quite effective from a machine utilization standpoint, the job queue would get so long during peak periods that users grew impatient. An additional enhancement was made which reported the queue length when the request was initially queued. This gave users a more accurate expectation about completion time. Additionally, when a queued job was resubmitted, the current position in the queue would now be displayed. These changes completely eliminated erroneous inquiries regarding the status of the web server.
After over a year of operation, we had an additional application to release and decided to migrate the server to a Linux/Alpha system running Red Hat 5.0. The switch to glibc exposed a bug in GNQS that was initially difficult to find. However, since the source code was available, I was able to find and fix the problem myself. I have since submitted the patch to Stuart for inclusion in the next release of GNQS and contributed a source RPM (ftp://ftp.redhat.com/pub/contrib/SRPMS/Generic-NQS-3.50.4-1.src.rpm) to the Red Hat FTP site.
Queuing requests with GNQS allows another interesting option which we may pursue in the future as our processing demands increase. Instead of migrating the server again to an even more powerful machine or to the complexity of an array of web servers, we could retain the existing web server as a front-end server. Without any changes in the CGI scripts on the web server, GNQS could be reconfigured to distribute queued jobs across as many additional machines as necessary to meet our response time requirements. Since GNQS can also do load balancing, expansion can be done easily, efficiently and dynamically with no server down time. The number of queue servers would be completely transparent to the web server.
There are a number of ways to handle web applications which require significant back-end processing time. Optimizing application servers requires different techniques than optimizing servers for high hit rates. For application servers, the limiting resource may be CPU, memory or disk I/O, rather than network bandwidth. Response times to given requests are expected to be relatively slow, and informing waiting users of the status of their jobs is important. Queuing requests with GNQS and referring the user to a results page has proven to be an effective, easily implemented and robust technique.
Thanks to Stuart Herbert, GNQS maintainer.
This work was partly supported by grants from the Department of Energy and the National Human Genome Research Institute.
First, I want to give a small explanation on the backgrounds of this document. There are several parts which lead to my advocating of Linux in the corporate environment.
First of all, it is already four years since I discovered Linux. It is only recently however that I really started using Linux itself. I used some GNU tools on the DOS and OS/2 platform, but only through recently expanding my storage could I install Linux. I printed some manuals, subscribed myself to the Linux Journal, I try to read the Linux Gazette frequently. Well, I consider myself almost a fan of the first hour of Linux.
Secondly, since the beginning of 1997 I have worked in a traditional mini/COBOL/database environment and I have noticed that the people who use these systems, find a lot in such an environment : easy to control and operate, you need only one person to program, background operation etc. The other side of the coin is that these proprietary systems are expensive. You pay every year an expensive maintenance contract or you pay an expensive price for reparation and upgrading.
My third reason, last but not least, is that I have never liked Windows in any of its incarnations since 1990. It generated GPF's for unknown reasons in 1990 and eight years later, it still does. It forces people in buying expensive hardware, which then cannot be utilised efficiently (if you don't want to crash).
These three reasons have lead me to the writing of three document, which I want to be published via the Linux Gazette. The reasons for this is that I found that the Linux Gazette is also read by people who have other system backgrounds than only DOS or Linux, and this is crucial for the objective that I want to reach.
This objective is in its essence the same as Linus Torvalds says, and it is :World domination. However, I have my own reasons to believe that world domination will not be attained only through the PC, workstation and Internet applications market. I believe that Linux has the potential to compete in the corporate marketplace. Alas, there are still a lot of holes to be filled in before this will come true. However, I also think there is enough potential among the Linux enthusiasts to make this dream come true.
The following text consists of three parts in which I was trying to order my ideas about what Linux further needs to attain the stated goal.
In the first part that I wrote, I am trying to compare Linux systems with mini- and mainframe-computers that I know and their architectures and I want to make an appeal to people who might be interested in developing Linux for large systems. I posted it on several c.o.l.* newsgroups, but I did not receive much response (only 1 person seemed interested).
This document should be thoroughly cleaned up and restructured. The main reason that I send over the Internet as is, is that I want to know the amount of response it generates. If there is no interest whatsoever, then the project will be cancelled. If you made it through here, please read on. Any ideas to have a good working title or something like that, are always welcome.
This document doesn't have the status of HOWTO. If I would assign it a status, then it would be something like an RFC, although not that official.
I apologise if things are not always clear. I need to document some parts with graphics to provide a clearer understanding. It should probably also be created as an sgml-file, to have more processing power.
Although this paper is sent to different linux newsgroups, it should be best to try to pick just one newsgroup to communicate about this document.
This document is by no means complete. It attempts to define a framework to develop and deploy Linux as a mainframe operating system. If any idea's in this document have duplicates somewhere else in the Linux development community, I would be glad to know of them, so that
This document is for the moment completely my own responsibility and my own copyright. It may be distributed everywhere, but I am the only one who may change it. Please, send questions and suggested changes to my email-address jurgen.defurne at scc.be. All trademarks acknowledged.
I intend to put much time into this project. I have a fine, regular job working daytime as a COBOL programmer, so time should be not really a concern.
The ideas in this document are a reflection of my own experiences in working with computers and things that I have read about in a whole bestiary of publications (magazines, books, RFC's, HOWTO's, The Web, Symposium records, etc...). The basis is this : Linux is highly scalable. For me, it has proven to be far more scalable than any MS product. I run Linux on the following systems :
Some of these systems are interconnected, others not (yet). With the use of telnet, X and TCP/IP it is possible to use these systems together, to run tasks on different systems etc. But I want more. What I would really like is that these interconnected systems can be viewed as one single system, with a common address space, and where their individual resources are added together to form a more powerful computer. The main target would be to make it possible to introduce Linux in environments where traditional minicomputers are used for data-entry and data-processing. This may sound like pretty ambitious goal. I don't know if it is. What I do know is that these are environments where high availability is a top priority (Note 1).
Another reason to do this project is the fact that in the beginning of the year Tandem has built a mainframe computer using 64 4-way SMP systems, NT, their own interconnection software and Oracle Parallel Server. Why shouldn't we be able to do something alike ?
This document must describe not only software, but also hardware and system procedures. I hope to revise it very regularly. I would like it to contain links to used source code, schematics, construction plans, all used sources and a history and possible planning of the project. It should also give people who want to make money from Linux the possibility to do this on a professional level. That is, they should be able to help companies with processing requirements to assess their needs, give advice on required hardware, install and implement the system and provide service, maintenance and education.
I haven't had a regular programming education. I am an electronics engineer. After school I got into microcomputers and programming and I broadened my education with courses on business organisation and industrial informatics. My experiences in the mini/mainframe world date back from as recently as januari 1997. At first I got to work in WANG VS (Note 2) environment, now I am still working as WANG programmer, but the WANG's have a duty as front-end input processors to the mainframe (Bull DPS8000/DPS9000) and as legal document processing systems. In my first job, the WANG VS minicomputer was used more as production mainframe system.
Now, what do these systems have in common ?
The main difference between the mini and the mainframe is in the operation of the system. The four main tasks that have to be done on a computer system are administration, exploitation, production maintenance and development. On a mainframe these tasks are done by different people, on a mini these tasks can be done by one person, or shared, but you don't need full time personnel for the different tasks (except for programming, that is). The system running on a mainframe can be sufficiently complicated that some tasks or operations may only be done by some trusted personnel.
Operating the system comprises the following tasks :
Basically, the ability to handle tasks efficient and fast. If you want to know more about the chores of operating systems, there is enough literature available (see literature list). The basic problem in running a large computer system is the difference between batch-operations and interactive or real-time operations. You want batch programs as fast possible to be executed and you want for the other kind a fast response time. The basic problem with PC's versus mini/mainframe computers is that the IO structure of the PC is very primitive. This is starting to change, first with VESA, now with PCI, but it still comes nowhere in the neighbourhood of a minicomputer. Basically, these systems always have a separate internal processor (or more than one) on the IO bus to handle data transport between devices and the memory. With I2O, this should become available to the PC world, but it is still proprietary and not available to Linux and/or Open Source developers.
Tasks compiled for x86-architectures tend also to use more memory. Let's take some examples from minicomputers and mainframes I know about and have access to documentation.
| System | Main memory | Clock | Bus size | Users supported |
|---|---|---|---|---|
| WANG VS 6 | 4 Mb | 16 MHz | 16 bit | 32 |
| WANG VS 6120 | 16 Mb | 20 MHz | 32 bit | 253 |
| WANG VS 6250 | 64 Mb | 50 MHz | 32/64 bit | 253 |
| WANG VS 8000 | 32 Mb | N.A. | 32/64 bit | 253 |
| BULL DPS9000 | 2 x 64 Mb | N.A. | N.A. | N.A. |
| BULL DPS8000 | 2 x 32 Mb | N.A. | N.A. | N.A. |
These systems are smaller than PC's in terms of memory, yet they support more users and tasks than a PC would do. I wouldn't use my Toshiba portable to support ten users on a database. Yet, that is what the WANG VS 6 is (was) capable of, with the same characteristics.
This is for the moment my main criticism of standard PC's and their software : they are extremely inefficient. The first inefficiency comes from the methods used to lower the price of a PC : the CPU is responsible for data transport between devices and memory. You have DMA available, but it isn't very efficient. The second inefficiency comes from the software mostly used on PC's : it takes up much space on disk and in memory.
A third inefficiency is in the software itself : it has so many features, but these aren't used much. The more features in the software, the less efficient it becomes (Note 3).
There is another thing to be learned from mini/mainframe environments : keep things simple. I don't think the current desktop/GUI environment is simple. It doesn't have a steep learning curve, but basically what you have are super souped up versions of what are basically simple programs. When writing programs or designing systems, one should always keep in that after a certain point it costs more effort to add more functionality to a program, while this functionality decreases efficiency.
In the area of parallel computers there is the Beowulf system and associated libraries. Their basic target is parallel processing for scientific purposes, while my purpose is business data processing. As I see it, some of their goals walk parallel with mine, especially in the areas of existing bottlenecks : the network, distributed file access, load balancing etc. However, the way business programs are run differs from scientific computing. MPP is also more in the way of creating a computer to run really big tasks, while on a business machine you have logins from users for data querying, transactional processing, batch processing of incoming data, preparing outgoing data, establishing communication with other systems. In this sense, what we are looking for is not to distribute one task over several computers to speedup processing, but to serve up adequate processing power, data manipulation facilities and information bandwidth for a large number of users. These goals need different OS support than MPP.
I have studied the Beowulf structure (a Beowulf HOWTO is available on the Internet). The Beowulf structure works is a MPP system in which only one computer effectively runs the application. All other nodes in the system are slaves to this one CPU. This is why the Beowulf system is only partially suited to attain my goal.
We need to start with a set of completely defined Linux operated computers, from now on called CPU's, which are somehow connected to each other by means of an abstract communications layer or CL. This CL can be implemented using serial connections, Ethernet, SCSI or anything else that we can devise to make CPU's talk to each other. A CPU may be a single-way computer or a multi-way SMP computer.
I think the end point should be to view the system as one single entity. To do this, the following requirements should be met :
One of the fundamental changes in the OS should be the way exec() operates. When exec() starts a new process, this could be on any CPU. The original links need to be preserved and processes should end in the same way as always.
Interprocess communication is straightforward I think. What I would like to know is if it is worthwile to strive for a system view in which all memory is mapped into one address space ? (Idea behind it : provide every CPU with the same view of the system : it's OS, followed by the memory pools of all other CPU's mapped into the same address space). This is what NUMA (non-uniform memory access) is about. Can the Linux community attain this subgoal, or does it need to much specialised resources ?
Some key parts of Linux should be redesigned or replaced by fault-tolerant parts. The largest part which comes to mind is the file-system. A few months ago I had a nasty experience. A connector on the cable of my SCSI subsystem had a defect, with the consequence that the system of a sudden completely froze while I was busy using X-Windows. The trouble with e2fs is that on these occassions the whole filesystem gets corrupted. This should be made more sturdy.
The other part is that the system may not freeze on these occasions. It should be possible to provide a bare minimum of functionality, eg. that the kernel takes completely over and switches to text mode to provide diagnostic information or tries to create a core dump.
Another problem that I have encountered is the lack of reliability when a harddisk drive gives trouble. What happened to me whas that on using an old SCSI drive the kernel and/or e2fs started to write strange messages when I tried to use the disk. When the system encounters problems with devices, the problems should be logged, the operation should be stopped and informative messages should be displayed.
Other key features in the area of HA should be the tolerance of the complete system when a CPU is missing. A CPU may only be added when it passes the self test completely and finds out that everything is working fine. When a CPU quits while being in the system, there should be possibilities to restart processes which have been interrupted. For this one should provide the programmer with features to help with this problems : a transactional file system, checkpoint functions (other ?).
The last idea I think of is maybe the possibility of swapping a complete task between two CPU's. A task consists of CODE and DATA. You don't need to save CODE. DATA can be completely swapped to harddisk. If you have a way to transfer the process information from one CPU to another, then it should be possible to reload CODE and DATA and restart the process on another system.
There are two targets. The first is the creation of an extension which combines several Linux PC into one system. Users and processes should get a same view of of the complete system as one system. This should also mean that certain administrative chores should depend only on centrally stored and shared information.
The second one is to add more and better managed fault tolerance, preferably more interactively managed.
Well, this is it. I hope that people ask sane questions, that I don't get flamed and that it raises enough interest to advance Linux to a higher level.
Ths reference list is clearly not finished. I need to obtain more details about some works.
The Linux High Availability White Paper.
The Beowulf HOWTO
The Parallel Processing HOWTO.
Andrew S. Tanenbaum, Design and Implementation of Operating Systems
Note 1.I worked for 16 months in a small transport company. The core of the business was contained in a WANG VS minicomputer. If the system was offline, then nobody could do his work properly. The system was basically a database to store dispatching operations, the revenues of all operations, the cost control and the accountancy. I think there are many small firms, who can't afford mainframes, but who need more processing power than the average PC can handle, and where many people need different views of the same data.
Note 2.The WANG VS is a particular good example of proprietary solution which does an excellent job, but with a very steep price. They are very expensive for the initial buy, the expansion of the system and the maintenance. I think this is one of the main reason's why people want to get rid of their WANG systems. You can buy, expand and maintain an HP system for one tenth of the price the WANG VS costs.
Note 3.If you wonder why I emphasize efficiency : I became interested in microprocessors in 1980 when you hadn't much microprocessor and memory. My first computer was a Sinclair ZX Spectrum with a> whopping 48 kB RAM. I am still astonished what some programmers could do with that tiny amount of memory. There are other points besides this : what processing power could be freed up if you were able to use all those wasted processor cycles in the common desktop PC's ? For small companies, a PC is still rather expensive. Combining the power of their PC's could maybe give them an extra edge in their operations.
In the second part I am trying to develop an architecture to extend Linux into a parallel processing system, not for numerical processing like Beowulf, but for administrative dataprocessing.
The goal of this document is to establish the components which should comprise the project which was mentioned in the previous document (Linux mainframes). To do this, a description of the boot sequence will be given, together with the possible failures and the solutions.
Before attempting this, however, I want to give a short summary of the guidelines which should lead us toward the goal of Linux systems which can be deployed in corporate environments.
Minicomputers and mainframes provide reliability and high processing power. The reliability is largely obtained in two ways. The first one is in the design of the system, the second one is the existence of a thorough support department with online help and specialised technicians. The emphasize in this document is on the hardware side of the system.
High processing power is obtained in several ways. They involve the use of cache-memory, wider data-paths, increasing clock frequency, pipelining processing and efficient data-transfer between memory and IO.
On the reliability side the system is dependent on hard- and software. If we are to use currently available parts (motherboards and cards) then the only thing we can influence is the way systems are assembled. Care should be taken to avoid static discharges, by using anti-static mats and bracelets.
On the software side we have the Linux operating system which is very reliable, with reports of systems running for months without erroneous reboots.
However, hardware can fail and in this respect I think that there still needs work done on Linux. If the error is not in the processor or the system memory, then a running system should be able to intercept hardware errors and handle them gracefully. If at all possible, system utilities should be available to test the CPU, the system memory, the cache and the address translation system.
The Linux High Availability White Paper documents clustering of small systems. Later on in this document, some other techniques will be proposed.
Processing power comes on several levels. On the first level, that of the CPU and the main memory we can't do much. With current motherboards with bus speeds of 66, 75 and 100 Mhz, we get data transfer speeds between memory and CPU of 264 MB/s, 300 MB/s and 400 MB/s. These should be sufficient for most applications. Memory is cheap, sizes of 64 to 128 MB should also give headroom for large applications.
The largest problem with standard motherboards is that all IO needs to be handled by the CPU or else by a slow DMA system. This means that a large part of the operating system is being used by device driver code. In mini/mainframe systems this is not the case. All IO is handled by separate IO-processors. These IO-processors implement the device drivers and as such free a large part of the central processor.
To relieve the central processor of this burden, there are three solutions. The first one is being implemented by the I2O consortium. It defines standards for intelligent IO-boards on the PCI bus. These boards can transfer the requested data themselves to the main memory of the CPU. The only problem is that as far as Linux is concerned, I2O is proprietary.
I think that two other solutions should be possible. The first, and probably easiest, is to use an SMP motherboard and program the operating system so that one processor is completely responsible for all IO, and the rest of the CPU's do the real work. Another idea is in the absence of SMP use two motherboards, run one with an adapted version of Linux to handle all IO and use the other one to run only applications. The only trouble here is which system will be used to interconnect the motherboards. Especially in the case of mass storage devices, you want to stream the data from the device as fast as possible into the memory of the application. Currently, this means using the PCI bus in one way or another.
Since we, as Linux users, have no sight on the design process of motherboards, reliability should be obtained through good standards of assembly and by implementing redundancy.
To obtain more processing power, the main CPU should be relieved as much as possible from IO. This could be implemented by using SMP or by interconnecting motherboards.
Based on the previous ideas, using several motherboards interconnected by a high-speed network could give us the following benefits :
To obtain these benefits when the system is assembled, some operating system changes need to be provided. It is possible to interconnect computers and make these work in parallel, but all administration must be manually accounted for. So, what we need when the system is booted, is not a vision of several separate systems, but only one system.
When booting the system, all nodes start in the usual way : installed hardware is identified, necessary drivers are run, a connection to the network should be made, NFS drives should be mounted, local file systems should be checked and mounted.
In the case of a normal system, all background processes would be started and users should be able to log in on the system.
When the system should be seen as one complete system, the boot sequence should be modified at this point. Resources which are normally only accessible on one node, should be shareable throughout the system. To build a common view, every node should have access to a common file system. In this file system the directories /dev, /etc and /proc should be accessible by every node.
The directory /dev contains all shared devices. The directory /proc provides access to system structures which should be shared by every node. The directory /etc contains the necessary files to control the system :
Every operating system on every node must be adapted to work via these shared directories.
To control the creation of this shared system, one node will have to be designated 'master'. After the initial boot sequence, every node will have to wait for the master to initialize the network. This initialization can proceed in the following way :
Started processes fall apart in two categories. Local processes run on the nodes which contain the resources that the process needs access to eg. getty, fax drivers, etc. Global process are independent of hardware and should be able to run on any node in the system.
Any node should also be able to start a new process on the system. By using a load balancing system, all started processes must be evenly divided over all nodes.
If a master fails while the system is up and running, then the basic coordination of the system is gone. To overcome this problem, a backup master must be defined. This backup master needs to keep an updated copy of all master system information. If the real master should fail then all nodes in the network should block themselves until the backup master has come up. The system should provide dynamic management of nodes. This means that nodes must be attachable by using system calls. This goes via the master, which then adds the system on the network. If a node must be detached, then none of its resources should be in use, otherwise the call fails.
If a node fails when in use then this surely will pose problems. A failure can show itself on the network (network interface problem, processor error) or local. If a process uses a remote device, it will do this by means of messages which are sent over the interconnection network. In the case of malfunction, the addressed node won't (can't) answer anymore. The OS must block the process until the malfunction is removed.
If there are problems in critical parts of the system, device drivers or system processes should not blow-up the system or interfere with user processes, but they should have the means to correctly report the problem and block the processes which are using the particular resource. If the malfunction is on a local level (device) then the device driver can return a message stating the error.
The most critical part in the system is the interconnection network. This should be tested and tuned according to system demands. If possible, a fast protocol should be used instead of TCP/IP.
The view every node has of the system should be the same. Devices must be shareable accross the interconnection network. The OS should be extended so that the exec() function, which is basic for starting processes, executes on a global level.
Reliability should be built-in and configurable on several levels. A message-based protocol is needed to share devices across the interconnection network.
Basically, there are for the moment two interconnection systems which can be used of the shelf.
The first is Ethernet. Based on the money to spend, you can assemble systems with 10 Mbit, 100 Mbit or 1 Gbit networks. Increasing bandwith means increasing processing power. To obtain the maximum of your bandwidth, the ideal is using an SMP motherboard in which one CPU takes care of all network-to-memory data transport.
The second one which attracts interest in the Linux community, is the SCSI interface. Using modern SCSI cards, up to 16 motherboards could be connected together to provide for parallel processing.
This is the third part. I have compiled some cases where I have participated to highlight some points that need more support in Linux.
Through several enhancements (Beowulf, Coda FS, Andrew FS) Linux gets more and more powerful. But how powerful is powerful really ? Linux is announced and used in more and more places, but there is a serious lack of numbers on the capacity of Linux in different environments and configurations.
This is however a crucial point. In many environments, Linux gets introduced through the reuse of PC's (which is in itself a good point). There are however other environments where the introduction of new hard- and software depends on the provision of hard numbers for acquisition, deployment, education, maintenance, infrastructure and depreciation of systems. This can range from a small office which only needs to cough up the required cash up to a financial institute which has large dataprocessing and communication needs.
In some of these areas Linux hasn't probably even touched anything because those people use computers as a means to an end. The computer itself does not stir their imagination. They have tasks to be done and the computer is their instrument to complete those tasks faster and more precise. These are the environments which are lured into buying MS products. I know however several people which work in various different Wintel environments and none of them are satisfied. Some complaints :
Lock up of course : power users lock up more easily their PC, because they use a lot of applications next to each other.
Unexplainable configuration changes : you enter your office and your application does not start. Reason : some ASCII text file has reverted to a previous state (I had this one several times with the TCP/.IP 'services' file).
MS Office for Windows 95 : You can not seem to use Word for large documents (this is a complaint from a user in a large company).
Windows NT : can not be deployed in situations where older applications need access to older and/or proprietary hardware.
I am sure anyone who has ever used the system, knows other bugs.
I think that one of the reasons why Linux isn't more employed in these environments is that it is mostly deployed using a single type of configuration existing of an IA32 CPU, a PC AT architecture, IDE/SCSI disk subsystem, an Ethernet NIC and standard serial devices. This makes it very easy to use Linux in the following places :
These are technical solutions for technical problems, implemented by technical people. However, for some places, some pieces are still missing and there are places where Linux could be used, but where it is not. The usability of Linux still depends too much on the technical skill level of the user. This should not be necessary. Companies should be able to deploy Linux quick, efficient and flawless. Introductory courses should be provided. This will mostly mean migrating from Windows knowledge to Linux knowledge. People should be made to understand that there are three pillars in the usage of a computer system and/or program :
On the system level these should be integrated transparently and tightly. A user shouldn't need to go through heaps of paper and manuals to find something quick, so menu driven is probably the best answer for this, with good context sensitive help. I even think that from the point of view of the user, things should be accessible under a heading 'Applications' where all his production programs should reside, and a heading 'Maintenance' where operational, administrative, system maintenance and diagnostic programs are located.
If we want Linux systems to be used more in environments where people are not concerned with their computer per se, but as a means to do their job, then support will have to grow on several levels. To project these levels, I will present some cases more or less detailed. These cases present environments where I have worked, customers which needed support, people I know.
With this I mean the family sized company which provides some basic services (grocer, plummer, carpenter, etc...). At most two persons are responsible for handling all administration. This consists mostly of two parts : accounting and handling of incoming/outgoing messages. The first part of the problem is providing this environment with a suitable accounting package which is applicable for the country where the company resides.
The second part of the problem is handling all incoming and outgoing messages. This requires access to three channels : phone, fax and e-mail (if there are any other options then these are probably too expensive for this environment). Depending on the situation, there could be constraints on the usage of the channels (eg. no channel should block another channel, when answering the phone, the fax and e-mail should not be prohibited and/or prohibit each other). The configuration could probably be extended using a PABX card in the system, to provide extended telephony services via Linux.
Like it or not, but these people have become accustomed to using WYSIWYG word processors and spread sheets, so the least that must be done is provide them with this functionality. There are at least two good packages available for Linux in this respect. Another thing that should be provided is a customer database which is closely linked to the former package. Creating new documents and using fill in documents from a user entry should be a must. Creation and insertion of simple graphics should be an available option too.
If we consider at most two people then the system could be configured using two workstations of the same capacity, where some tasks are shared between each other, or it could be done using one more powerful system, which provides all services, and one cheap PC workstation, configured as an X-server.
File- and print-services, bookkeeping, inventory control
The company where I first worked from 1990 to 1991 had a Novell Netware system installed. We used the system to provide printservices for Mac- and PC-systems, as a repository for all kinds of drivers and diagnostic software and as a shared database via the bookkeeping and inventory control program. Everybody who needed access to the network had his or her own PC or Mac. We mostly used DOS back then, although with the introduction of Win 3.0 some people migrated to it. Everybody had access to a phone and there was one central fax in the administrative department. We installed and maintained PC's and Mac's for graphical applications. These applications provided output for typesetting printers (mostly via Postscript) or plotters. The supported applications where Adobe Photoshop, Aldus Pagemaker and AutoCad. We were also a reseller of the bookkeeping package that was used on the network.
The printing could be spooled to several large laserprinter, a high-speed dot-matrix printer and a photographic typesetter.
File services under Linux are probably the easiest of problems. I networked, recompiled, linked and started a small TCP/IP network using two computers in less than an hour. NFS is very comprehensive, as are telnet and other TCP/IP services. If you need to provide only a central server, then the following things need to be done :
For the workstations the following needs to be done
The main difference between Novell and NFS is in the administration. On a Netware server, all administration is kept central to the server. The only thing which needs to be done on a workstation is load an IPX driver at boot time. On a TCP/IP workstation, some administration is kept centrally and some administration is kept locally. This makes the process of maintaining and updating the network more laborious.
Installing print services under Linux is generally much harder than under Netware. This is because all settings are to be added manually using a text editor in the file printcap. But, since this is a very structured file, with a rather small set of commands, why hasn't any body ever written a dialog system to scan printcap and present the user with an overview of available printers and the possibilities of adding and modifying printers and their settings ? This would be a great step forward in installing printers. Filters for different types of printers could be presented, so that the configuration on the network could be simplified (as an aside, RedHat provides such a system).
The other part of printing is the operation of the queues. The lpd system provides only command line control. But since this system is also understood very fine, why haven't there been any attempts to rewrite the lpd system for menu-driven operation ? After all, entering a command or pressing a function key can invoke the same behaviour. All queues and printers can be presented to the user, with the possibility of providing more details.
The accounting program was written in Clipper and did not use Btrieve. This means that all access to the data in the files generated a lot of traffic over the network. This was alleviated by segmenting the network in three parts so that the accounting department didn't interfere with the other departments. The whole package ran under DOS. In the course of years, the company which programmed the package made in 1994 the transition from Clipper to FoxPro, and only as recent as 1997 they made the transition from DOS to Windows (with the DOS version still being sold and supported).
This presents us with a case of providing support for migration of xBase dialects to Linux, while adding value to these languages through transparent client/server computing. There should also be support for people migrating from these DOS-based systems to Linux. There are a whole lot of programmers who work alone and who make a living by writing and maintaining small database applications for SOHO users (using xBase and several 4GL tools which run under DOS). Providing incentives and support for these people to migrate and to help their customers migrate could give a double benefit to Linux. The key lays of course in the way that support for these tools becomes available under Linux or that conversion tools become available under Linux.
Printing support under Un*x and hence Linux has always strongly been oriented at typesetting. Providing support for Postscript should not be a problem under Linux. Adding a typesetter should be as easy as installing a printer on a server or on the network via a print server. There are already some strong graphical packages available for Linux. In this case, migration is a question of importing and/or converting graphical files and showing the user how to do the tasks he does normally with the new application.
Plotting and/or cutting should be the same as printing. The application program is responsible for translating it's own internal drawing database into a format that can be used by the addressed peripheral.
Drafting departments are a case where networking and central storage are really put to the test. It consists of a drawing database, which is a front-end to the drafting programs. User should be able to look at drawings, create, edit, delete and print drawings and collect usage statistics about drawings. In addition, only one user should be able to edit a drawing or part of a drawing at one time, and it should be possible to see who is editing what. If this all sounds like using a file system, then you are right. The difference is that you only use one type of file. I worked on one system in the previous case. It was written using Clipper as a front-end. I know of other environments where Autocad is used, but under a WinNT network, and there are some companies who deliver complete turnkey solutions consisting of powerful minicomputers and proprietary workstations for real high-end drafting work.
Providing the incentive to migrate to Linux consists in providing a powerful server with large storage to accomodate all the drawings and a fast network to deliver them to the workstations. All workstations should be tuned to the max to deliver the utmost in graphic display and manipulation. Of course, utilities are necessary to convert the original drawing database and all the drawings. Networking should be flawlessly, and the program which uploads the drawing should provide an indication of the time necessary to get the file and where it is in the process.
This pertains to my previous job : a small transport company, which had ten years ago decided to implement a computer system to automate several tasks and to keep a database of all done transportations. They had taken WANG VS, which was back then a successfull system, with many advanced features. Custom software had been developed by an outside company first, by an in-house programmer later. The system contains a very comprehensible fax package, which can be used by anyone, but with strong security features. All outgoing messages are put in one queue, where the operator can change their times and/or priorities. All communication with the minicomputer is via terminals or via emulation cards on PC's. Accounting is also done on the minicomputer, but the two systems are not linked. The system is also equipped with a background task which controls batch tasks in a queue.
There are many medium-sized companies which still use minicomputers and who have a problem shedding them, due to their highly specialized software. Migration from a Un*x system to a Linux system should not pose as much problems as migrating from a completely proprietary system to Linux.
The main problem with these mini-computer systems is their high maintenance cost. That should be the most pressing reason to migrate, although Y2K could also be an incentive (not so with WANG VS, which is fully Y2K compliant).
To provide the same functionality a DBMS package should be available which provides a data dictionary, a screen design package and a COBOL74 compiler with preprocessor to translate simple SQL SELECT statements. There are several packages available. One package aids in the migration from WANG PACE (the WANG DBMS) to Oracle (at the moment Oracle has only announced porting Oracle to Linux), while Software AG has tools to port WANG PACE applications and screens to ADABAS. On part of the compiler, where I work currently the porting is done from WANG to HP-UX using Microfocus Cobol. The security features of the database package should at least contain rollback recovery. The provided file-system should absolutely not be e2fs. Reliability should be favored over speed. When the power fails the file-system it self may be damaged, but these damages should be simple to clean-up. Damages in transactional files are to be repaired with the rollback option.
On the hardware side, I noted that SCSI II provided enough speed to handle some 20 users, but ... this was a system with a specialized IO-processor to handle all data transfers between main memory and all peripherals. To know how Linux fares in this, benchmarks should be run and numbers should be provided. In our last configuration (a 50 MHz CPU with 64 Mb), under a heavy load, our response time was under 10 s.
Fax support must be provided to interactive applications, but also to batch applications.
Batch processing of all tasks should be supported. Some programs can be started, used to enter selection data and then launched at will in the background or in the foreground at a time and day the user can enter. cron is fine for highly skilled people, but not for your data-entry clerk, so you need a front end which asks the date, time and repetition rate of your job. The application itself should be able to provide the required parameters.
This company builds cash register systems using mostly common PC hardware and one piece of proprietary hardware which interfaces to a magnetic card reader, a bar code reader, a money drawer and a keyboard/display/pricing printer. The cash register is connected via a network to a server which provides an inventory and a price list. Upon booting, the cash register connects to the network and loads its OS from the server. Every server has the possibility to connect at night to a central database to update its pricelists and to order items which are getting out of stock.
For the cash register, a multi-user, multi-tasking OS is clearly overkill, while in the case of the server, multiple cash-registers could connect via the network to the server. The cash register would benefit, though, from multi-threading.
Software development for servers and departmental systems is usually done with a 4GL tool, with a higher-level language only for those parts which 4GL does not support.
The production environment of this company consists of 5 WANG VS minicomputers, used for data-entry, data-preprocessing and to connect agencies remotely through a telephone line. It consists also of a Bull mainframe system with two CPU's, 128 Mb memory, 240 Gb of on-line storage capacity, a transaction processing system consisting of a network database and a screen editing and runtime program. All this is controlled using JCL and COBOL-74. TCP/IP is implemented between all systems.
Replacing the minicomputers with Linux systems should be relatively straight forward. Since no WANG PACE is implemented on these, only migration of the COBOL-74 programma's needs to be done. Data entry and remote connection could be done using telnet and/or serial connections. Transferring data between mainframe and other systems is no problems. All this happens using FTP.
Now, let us think really BIG! Could a case be made to build a system using Linux, which can replace a mainframe computer, given the specs above ? As said above, more numbers and benchmarks are needed on Linux and its implementations to know how powerful Linux can be.
These cases resemble the SOHO, but additionally need very specialized software to support their job. This software is mostly written by very specialised companies (niche software). What would they need in terms of software and maintenance to be convinced to migrate to Linux ?
One of the answers is surely that they can migrate their existing applications easily and that conversion of their source code is supported by tools and API's which provide the same (or better) functionality than their old tools.
Configuration of these systems may be more specialized. Normally the user would only use his system (enter customers, query the system). All administrative and configuration chores could be left to the implementor. The applications themselves are already as user-friendly as they can be, due to their specialised nature.
I have presented several real-world cases, where Linux IMHO could be used. In most cases there are two recurring themes.
The first is the need for migration support from other platforms to Linux. This support spans a whole range, varying from multi-platform compilers over database migration, up to replacement user applications.
The second is the need to provide more user-friendly administration and operation. This may be as well through character-based dialog boxes as through GUI systems. In any case their access should be more centralised.
Other themes which pop up are the following :
The Xbase file structure has been around quite a while and was one of the first widely available DBMS tools for micro computers. It has become a de-facto industry standard for text based databases and is supported by many vendors to include the Borland Database Engine, Microsoft's FoxPro, Clipper, Sequitor's Codebase and others. Xbase type datafiles will be with us for a while.
The Startech Web Server at http://www.startech.keller.tx.us/xbase/xbase.html maintains a public domain, open source C++ library for accessing Xbase type datafiles in a multi-user environment. The library supports automatic record locking, memo fields (both dBase III and IV versions), and .NDX style indices. There is also an API for interfacing the library to an Apache Web Server and providing database access to web pages. Several example programs provide a framework for creating, browsing and updating databases. There are examples which demonstrate how to use the library with an Apache Web Server and using the library in conjunction with the wxWindows library. Some readers of this article will recognize the wxWindows library as a cross platform GUI C++ library.
In order to use the Xbase DBMS library, you'll need to have a C/C++ compiler. The original library was built on a Slackware distribution with the GNU public domain compiler, but there are examples on the site for using the library on other platforms including Windows, SUN, and VMS.
To downloading the library sources, point your web browser to http://www.startech.keller.tx.us/xbase/xbase.html and select the latest version, which at the time of this writing is version 1.7.4 dated 6/18/98. There are a couple of flavors available, but for the purpose of this article, download the UNIX tar version. Also, you may want to grab the HTML documentation for using the library at the same time. Alternatively, you can get the software via ftp ftp.startech.keller.tx.us and retrieve the software from the pub/xbase directory.
To install the Xbase library under the /usr/local directory, execute the following commands: cd /usr/local and mkdir xbase. The next step is to set up access rights to the Xbase directory tree. Your site may have specific protocols on directory access rights which you may need to address at this point. If not, then the commands "chown YOURUSERID.users xbase", then "chmod 775 xbase" will get you going.
Now create a source directory and copy the source code into it: "cd xbase", "mkdir src", "cp /home/of/xbase.tar.gz /usr/local/xbase/src", "cd /usr/local/xbase/src", "gunzip xbase.tar.gz" and lastly "tar -xvf xbase.tar". At this point the Xbase source code should be in the /usr/local/xbase/src directory and be ready to build the library.
Before building the library, review the options.h file. This file contains any of the Xbase configuration switches you may want or need to change depending on what you are trying to do. To build a DLL library, type "make dll". To build a static library, type "make all".
It should compile cleanly. Errors at this point can often be traced to the .h header files currently in use at your site. If you run into errors at this point, notify [email protected] for help building the library.
This sample program demonstrates a simple program which creates a sample database and index.
/* sample1.cpp */
#include "xbase.h"
main()
{
Schema MyRecord[] =
{
{ "FIRSTNAME", CHAR_FLD, 15, 0 },
{ "LASTNAME", CHAR_FLD, 20, 0 },
{ "BIRTHDATE", DATE_FLD, 8, 0 },
{ "AMOUNT", NUMERIC_FLD, 9, 2 },
{ "SWITCH", LOGICAL_FLD, 1, 0 },
{ "FLOAT1", FLOAT_FLD, 9, 2 },
{ 0,0,0,0 }
};
/* define the classes */
XBASE x; /* initialize xbase */
DBF MyFile( &x ); /* class for table */
NDX MyIndex( &MyFile ); /* class for index 1 */
SHORT rc; /* return code */
if(( rc = MyFile.CreateDatabase( "MYFILE.DBF", MyRecord, OVERLAY )) != NO_ERROR )
cout << "\nError creating database = " << rc << "\n";
else
{
/* define a simple index */
if(( rc = MyIndex1.CreateIndex(
"MYINDEX.NDX", "LASTNAME", 0, 1 )) != NO_ERROR )
cout << "\nError creating index 1 = " << rc << "\n";
}
MyFile.CloseDatabase(); /* Close database and associated indexes */
return 0;
}
Assuming you keyed the program source into directory /usr/local/xbase/myproj, type "g++ -c -I/usr/include -I/usr/src/linux/include/asm-i386 -I../src sample1.cpp" to compile the program and type "g++ -o sample1 sample1.o ../src/xbase.a" to link edit the program. The asm-i386 directory in the above include line is for Linux running on the Intel platform. Other platforsm require the correct include directory.
In conclusion, I'd like to say that although the Xbase library is not a 100% complete Xbase solution, it is a stable and reliable library capable of handling various database requirements. If you are looking for database libraries in general, or need access to Xbase files in particular, give Xbase DBMS a try. If you are a C programmer and new to C++ object oriented programming, the Xbase DBMS is easy to learn and will help transition you to the world of object oriented programming. If you have never programmed in C or C++ before, this library should provide complete enough examples to get you started programming in C/C++ with confidence.
Website Automation Toolkit is a collection of tools, most created by the author's company, which range from allowing simple configuration control over the look and feel of your entire site to remote creation of and updating pages on the site to shopping carts and simple database facilities. It is not a book about running and configuring web servers or teaching the Common Gateway Interface (CGI) protocol.
The introductory preface and first chapter address the motivation behind the book and a few of the benefits of using some form of automation in maintaining your web site. Next are two chapters discussing some of the alternatives (and alternative proprietary software) to the author's CGI-oriented approach to automation.
The majority of the tools provided are, in fact, Perl CGI programs created by the author's company. These tools are officially free. While the license in the book states that you are not allowed to redistribute them without permission, you are allowed to use and install them as many times and for as many clients as you wish. This seemed a bit contradictory, so I asked the author for some clarification. He responded with the following statement (used with permission):
I don't do courts, but the intent of the license is to prevent people from putting our utilities on shareware CD-ROMs without the supporting text. It's more of a support issue than an ownership one. I wrote the book because these things were far too useful to keep to ourselves.Chapters 4 and 5 mark the transition into the main part of the book by providing a short justification for why Perl is the language of choice, and a brief introductory overview of Perl basics. This overview is not intended as a guide to the Perl programming language, but merely to acquaint the user with some of the essentials so that later sections on configuring and customizing Perl scripts will be less daunting to the inexperienced.
The remaining chapters provide a tool-by-tool installation and instruction manual. There are too many tools to cover them all with any detail, so I will very quickly run through the remaining chapters and follow with my general impressions.
Chapter 6 covers SiteWrapper, a package that wraps your site so that all of your pages are served by a CGI program. Chapter 7 introduces Tickler, a program for soliciting e-mail addresses of visitors and notifying them of content changes. Chapter 8 follows with a discussion of the freely available Majordomo mailing list software for creating and maintaining mailing lists.
Chapter 9 addresses tracking visitors with discussions of the Trakkit tool (requires SiteWrapper) and the freely available Analogue program. Chapter 10 covers a Shopping Cart package (a modified SiteWrapper program) along with some order processing utilities.
Chapter 11 covers WebPost, the utility which, according to the author, sparked the book. This system allows you to create, edit, delete or upload pages to your site and automatically generate or update the cross links among pages.
Chapter 12 provides three search utilities for your site, depending on whether you are using SiteWrapper, WebPost or neither. Chapter 13 covers the AddaLink tool for creating and maintaining a hot list of links. Chapter 14 covers QuickDB, a simple text-based database engine with a browser interface for adding, editing and deleting entries.
Chapter 15 presents a Bulletin Board utility, and also discusses using FrontPage for a Discussion Board. Chapter 16 takes the next step by covering a couple of freely available Chat programs.
Chapter 17 provides a couple of search engine agents, one to submit a URL to a multitude of search engines and two more which report your location on the search engines. The final chapter presents BannerLog and ClickThru, tools which track and log click-throughs and page views of banner ads on your site.
I set up a dummy site on my Linux box for installing and trying out a few of the provided utilities. The installation instructions in each chapter are divided into UNIX and NT sections and are relatively simple to follow. However, some unfortunate problems arose.
There are .zip files for each package, and non-zipped directories for each of the packages on the CD-ROM. A mild inconvenience is that some of the .zip files were created with extraneous path information included, and the individual files in the non-zipped directories are riddled with ^M characters. The author has created a web site where you can find problem reports and corrections, and ``cleaner'' versions of the source files for downloading. The site is located at http://www.world-media.com/toolkit/.
Another inconvenience is that every Perl script must be checked (and possibly edited) for the proper path to Perl on your system, there is no script provided to automate this task, although writing one would be trivial for any experienced Perl programmer. Note that even if the first script you examine has the proper path, others definitely will not--so you must check and edit those with the incorrect path for your system.
More serious problems arise with the Perl code. None of the open calls for reading and writing files are consistently checked for success or failure. You'll first notice a problem when you install the SiteWrapper package and try to change the color scheme of your site with the included SiteColors program. The installation guide omits mentioning that your server will need write access to the tagfile.dat file where the color scheme is stored. Since the program does not check the return value of the open call, it will fail silently, your color scheme will not be updated and no error will be present in your server's logs. I'd seriously recommend locating all calls to the open function in all .cgi scripts and adding at least a ||die "$!"; statement to those that don't have it.
Other deficiencies with the Perl scripts are that they are not -w clean (for warnings), won't compile with the ``strict'' pragma, do not use -T for taint checking and use the older cgi.pl library rather than the CGI.pm module for Perl 5.
Even with the above comments and concerns, the packages are, for the most part, easy to install and get working. Installation and configuration of the basic SiteWrapper package took less than an hour, including time spent checking and cleaning the source code and creating simple header and footer files and a couple of dummy pages. When using this system, every page is served from a CGI program, even essentially static pages. This method allows for a great deal of flexibility and a centralized configuration style of management, but could become costly in terms of server load if your site is large or heavily trafficked.
I had a little more trouble getting the WebPost system running properly, mainly because I chose to set it up in a subdirectory of the SiteWrapper directory and a few issues were involved in getting the two packages to play nicely together. Once it was set up, however, it worked as advertised. While I found parts of the interface to be a bit clunky for creating web pages, it is a functional way to create and edit pages remotely using a browser.
Other tools were less problematic to install, Trakkit for example--I was tracking and logging myself within a few minutes of unpacking the package.
On the whole, if you are looking for instant ``shrink-wrap'' automation software with point-and-click setup and configuration, you'll be disappointed. However, typical Linux users accustomed to file-based configuration should have little trouble with these tools, especially if they already have some experience with Perl programming. The programs are not stellar examples in their present incarnation, but they can provide an inexpensive automation system for budding webmasters willing to get their hands dirty with a little Perl code. Hopefully, many of the concerns mentioned above will be addressed in a future edition.
Larry AyersRandolph BentsonKen O. BurtchJurgen DefurneJim DennisMichael J. HammelAndrew JohnsonJohn KacurDamir NadenDavid NelsonMike RichardsonJim SchweizerAlex VreniosColin C. WilsonDan York
Thanks to all our authors, not just the ones above, but also those who wrote giving us their tips and tricks and making suggestions. Thanks also to our new mirror sites. And of course, thanks to Ellen Dahl for her help with News Bytes.
About a month ago, my doctor diagnosed me as having diabetes. Since then, I have found I am becoming quite self-absorbed. I've had to go back to always thinking about what I am going to eat and when--a habit I had given up years ago. For a time, I've decided to become essentially vegan (though not fanatic about it--I ate one piece of bacon this morning). I'm quite amazed at the difference giving up meat and dairy products has made in my energy level. Of course, getting my blood sugar down has certainly been the best help in that area. At any rate, I'm feeling better than I have in at least 6 months if not longer, and that's good!
I will be going to San Diego this weekend to visit my grandchildren there. Haven't seen them in quite a while, so I am looking forward to it.
Have fun!
Marjorie L. Richardson
Editor, Linux Gazette,
Linux Gazette Issue 33, October 1998, http://www.linuxgazette.com
This page written and maintained by the Editor of Linux Gazette,