The Linux Gazette
Answer Gang Knowledge Base

Updated 27-Dec-2001
Maintained by Ben Okopnik (LG Contributing Editor) and Chris Gianakopoulous
Send corrections and additions to

As you might imagine, we often get asked the same questions, over and over. The perennial favorite of "It doesn't work!" is always good for a laugh; "NEWBIE NEEDS HELP!!!!!" is another. (If you want avoid being grouped with those who don't know enough to pick up the ringing Clue Phone, do yourself - and us - a favor and read our posting guidelines.) However, we also get asked lots of useful, interesting questions by people who have taken the time to think out what they want to say, and many of these are not only worth answering - they're worth preserving as reference material for others who might encounter the same problem.

NOTE: Remember that some of the information in the Knowledge Base loses its relevance as time goes on: syntax and usage becomes deprecated, tools get replaced by newer (and presumably better) tools, and writers look back at the code that they published years before and shrink in horror (this couldn't possibly be personal experience speaking, never!) Because of this effect, it is worth your while to read several articles on a given topic that you're researching, with preference generally given to the later ones in case of conflict.

Backup and Recovery
Before You Install Linux
Boot Loaders and Booting the OS
C, C++ and Java Programming
CD-ROM, Tape, Floppy and Other Storage Devices
CPUs and Motherboards
Compiling Programs, Using C Libraries
Configuring Mail
Databases
GUI, X-Windows and Window Managers
Games
HTTP/FTP/SSH/etc.
Hard Drives
Installing Linux
Installing and Using Applications
Interoperability with other OSs
Linux Distributions
Linux Tech Support Questions (prev. in LG-FAQ)
Miscellaneous
Modems and Dial-Up Networking
Network Adapters (Ethernet, etc.)
Network Configuration
Off-Topic (non-Linux)
Other Peripherals
Partitions and Filesystems
Perl Programming
Printing
Programming in Other Languages
Python Programming
Scientific Computing
Security
Shell Scripting
Sound
Switching from Other Operating Systems
System Administration
System Configuration
System Startup: From Boot to Prompt
The Answer Guy's Most Memorable Rants
The Kernel
UNIX Commands
Uninstalling Linux
Video Cards

Backup and Recovery

Corrupt Tar Archive
Data Recovery Vendor Seeks Linux Basics
Why is diff so crazy?
Seagate SCSI tape problem --or-- Tape Drive Errors
Duping a Drive Under Linux
Dell EIDE TR5 Tape Drive

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Before You Install Linux

What is Linux?
Need Help!!! --or-- Removing an OS

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Boot Loaders and Booting the OS

Help on LILO stopping at LI
Two OS
LILO hangs --or-- LILO Hangs in Switzerland
LILO Windows boot --or-- Keeping Both Hard Drives Connected
LILO Stopping at LI --or-- LBA and "linear"
Loadlin trouble
Windoze on 2d Hard Drive --or-- A Usable Example of lilo.conf for 2 Drive Dual Booting
Multi- Boot LINUX, NT and WIN98
Lilo --or-- Boot Stops at LI
Multiple append= Directives in /etc/lilo.conf
How do I do it? --or-- Installing to a 2nd HD
LILO Lockup --or-- LILO Stops at LI
Using LILO to boot directly to dos --or-- Setting the LILO Default
LILO, SYSLINUX, and more Boot Loaders

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C, C++ and Java Programming

Is This a Good Book for Linux Programming?
about the adaptation.

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CD-ROM, Tape, Floppy and Other Storage Devices

getting volume label for CD
The Best of: Burning .iso files under Windows
When you burn an ISO image to a CD... --or-- What to do with .ISO files
Making CDs
CDR used in scsi emulation --or-- Mounting CDs on IDE CDRW Drives
CD-ROM, Tapes, and more Removable Media

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CPUs and Motherboards

233mhz to 450mhz --or-- Overclocking a Motherboard? 233Mhz to 450Hmz?

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Compiling Programs, Using C Libraries

Limiting exported symbols --or-- More on Exporting Symbols from Shared Libraries
glibc --or-- Multiple Concurrently Installed Version of glibc

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Configuring Mail

Domain Renaming and E-mail Routing and Re-writing
MAPS, Razor, Procmail, Junkfilter, IMAP, and DNS
Procmail and regular expressions....(Snowwhite...)
Setup of Microsoft Outlook Express 5 for Sending of Clear Text
masquerade in sendmail is broken
Linux Newbie Frustration --or-- So many users, So few POP accounts
Aliasing in Sendmail Linux Gazette
IMAP/POP daemon on RH 6.0 and 6.1 --or-- Installing a POP Daemon on Red Hat Linux
MX Records and Precedence Values
Procmail Arguments
Mail Servers and Clients

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Databases

MySQL tips and tricks
Porting to Access

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GUI, X-Windows and Window Managers

Xwindows
GPM is interfering with x...
IP Masq and X
extra keyboard keys under X
xdm wont start a session --or-- XFree 4.0 and ":0.0 refused by server" Errors
Four Questions
run any remote X server at host box --or- Remotely Executing Graphic Apps
Redhat display --or-- Simple: Change X Resolutions on the Fly
Icewm and open xterm with root rights --or-- ICEWM Key Bindings (Macros) and X in "Toaster" Mode
Telnet goes X? --or-- Exporting a DISPLAY
fvwm2 and blank screens --or-- That Blankety Blanker!
rsh works but not -display... --or-- Permission Denied on -display
Dual (or more) Monitor support
Running XDM Without a console GUI
X respawning question and answer --or-- Another Solution, or a Different Problem
X Window Networking --or-- The X Graphical Environment

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Games

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HTTP/FTP/SSH/etc.

Bulk File Transfers from Windows to ???
Internet server specifications --or-- Web server/firewall hardware specifications, Apache and Zope
LinuxRedHat Errno 404
Some basic ftp questions --or-- FTP Daemon: Special Requirements

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Hard Drives

SCSI
Classified Disk - Low-level Format
cloning with dd
Here's a good question for you... --or-- CRC Error - System Halted
Hard drive --or-- Adding a Disk
Coping with Bad Sectors
Hard Disk Drives, Filesystems and Partitioning

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Installing Linux

RE: Download Linux
Kernel upgrade
Unable to Install Linux
Installing Linux without cdrom
Por favor Ayuda!
Linux Installation question
LINUX for SGI Visual Workstation
New to Linux
Please help I am at wits end
newbie installation question
Now what? --or-- Using a Downloaded .iso Image for System Upgrade

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Installing and Using Applications

Dependency Hell
question about fingerd
3d linux
linux anti virus?
calculate cpu load --or- Use the Sources, Dude!

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Interoperability with other OSs

Re: Linux solution to syncing with Exchange Address books
libguile --or-- A Be-GUILE-ing Question
source code of fsck --or-- Getting to the Source(s) of fsck
uninstall --or-- Uninstalling a tar.gz (tarball) installation
Find the source for specific program
Idled Daemon on Linux --or-- idled RPM for Red Hat
Telnet not working on recent RedHat/Mandrake --or-- Incoming Telnet for and Mandrake Users
Which RPM Provides A Given Set of Files?

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Linux Distributions

Here is a very stupid question ... --or-- How do I choose?
Distros
Best Linux Distro For A Newbie...?
Question from a quasi Novice... --or-- Linux is {Now|Not} UNIX
RedHat 6.0 - various problems --or-- Laundry List of RH 6.0 Problems

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Linux Tech Support Questions

How can I get help on Linux?
Can I run Windows applications under Linux?
Do you answer Windows questions too?
How do I find the help files in my Linux system?
So I'm having trouble with this internal modem...

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Miscellaneous

clock problem
HOWTO find a good laptop
question about fingerd
How can you do a recursive search to find broken symbolic links?
RE Solaris UNIX?
a question --or-- Linux, UNIX, what's the difference?
e-mails not getting through
background processes in Linux
Win4Lin nand NT = nil --or- Win4Lin's Limitations: VMWare's Strength?
rcp question --or-- UNIX User Tries Linux 'rsh'
problem with bash/vi editing mode --or- ksh Keybindings (vi Keys)
question --or-- How do you pronounce Linux?
linux mail server to an MS Exchange? --or-- Linux vs. MS Exchange for Mail Server
Redirecting stdin on telnet --or-- Redirecting stdin into telnet
Daemons
virus protection --or- Virus Protection for Linux: A Non-Issue ... But...
Other Servers
Etiquette and More Social Questions
If that could possibly have missed it... --or-- Everything Else

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Modems and Dial-Up Networking

pppd problem
getting 2 dynamic ip addresses
What ISPs Do We Use for Linux
Multiplexing ppp connections
Dial-on-demand users should know:
The New network On The BLock
getting 2 dynamic ip addresses
What IS "The Internet" anyway?
State of the Art in softmodems
Issues with a modem
Kermit protocol --or-- G-Kermit: The GPL Kermit Transfer Package
Kermit --or-- A bit more about C-Kermit
Free Linux ISPs in France
windows telnet/linux --or- automating windows telnet to linux
Automated Login Around a Challenge Card
Monthly Win (Lose) Modem Question
Modem Noises --or-- Quiet, Modem!
Winmodems
Ordinary Modems and other Useful Serial Devices

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Network Adapters (Ethernet, etc.)

Renaming Ethernet Devices
linux ether16 support --or-- isapnptools
Can't See Ethernet Card --or-- More on Linksys Ether16 Cards

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Network Configuration

How to let the world find your Linux Server when using DHCP
Timely Samba Release?
inetd and figlet
DNS and telnet
Piercing the Veil (ssh NAT/Firewall Piercing Trick)
IP Forwarding
File Tranfers with AIM (AOL Instant Messenger)
For Jim Dennis...Hello from South Texas --or-- Firewall for a SOHO
DNS and telnet
multiple subnets, one DNS
Networking
DSL on Linux Information
Suse Linux telnet problem --or-- Can't telnet to Linux server
Question --or-- Shutting Down the "ping Daemon"
Shutting Down the "ping Daemon" --or-- Shutting Down the Ping Daemon: Revised
Linux as a Win NT server --or-- Singing the Song for Samba
Routing a Linux Subnet --or-- Subnetting
soho linux network --or-- Two Node Network: How
question about ProxyArp --or-- ProxyARP
Telnet to linux box from NT workstation in NT LAN --or-- Connection Refused
connecting red hat workstation to nt server --or-- Linux in a Windows NT Domain (under a PDC)
linux using nt server data --or-- Accessing an NT Fileserver
More on TCP Wrappers and telnet Connection Delays
Disabling Anonymous FTP
Getting Addresses Routed: Use IP Masquerading or Application Proxies
Linux as a firewall/router --or-- FTP Through a "Firewall"
DNS ports... --or-- DNS Ports: A bit about Name Resolution Protocols
routing -masquerading --or-- Hello Routing, Goodbye Masquerading
Double Reverse DNS Strikes Again
Windows 95 Connectivity --or-- Needs Samba Configuration Advice
Red Hat --or-- Telnet gives: "Connection closed by foreign host..."
Linux Workstations Behind a Proxy/Firewall
rsh --or-- Really Wants 'rsh' to Work. Really
"telnetd connected:" But No "login" Prompt
Routing, Firewalls, and other "raw" Networking

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Off-Topic (non-Linux)

BIOS passwords - Bane of my existance
Recover password for SUN sparcstation --or- Root Password Recovery on non-Linux UNIX Systems
Lost CMOS Password
Comcast and IPmasq --or-- Short names for Long Domains?
Non-Linux OS Questions

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Other Peripherals

How can I view ascii data coming across my serial port? --or-- Serial Capture
Questions about Linux --or- Setting COM port speeds
serial port snooping --or-- Snooping on a Serial Port

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Partitions and Filesystems

LFS: Large File Summit/Support
Please need help !!! ext2 problem !!!
I can't seem to write to my vfat (Windoze) file system with any user other than root
Sizing the Home Directories: Quotas and Partitioning
accessing windows files --or-- Accessing Local DOS/Windows9x Drives from Linux
Which filesystem? --or-- Determining the Type of Each Filesystem
Partitioning Linux
booting larger than 8.4gb --or-- FIPS
LI boot problems --or-- Removing Linux Partitions
Binfmt/Exec Format Errors in /linuxrc on initrd
Linux DEVFS --or-- Linux devfs (Device Filesystem)
help....need to delete a linux partition
UVFAT --or-- Getting UVFAT
Disk Druid UI Failure? USE fdisk!
Need Advice --or-- Partitioning Advice

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Perl Programming

"crypt" function in Linux
2c Tip: Show TCP/UDP port usage --or-- Cross Comment: 2cent Tips

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Printing

Re: Printing to specific forms..
Checks vs. Plain Paper
Winprinters
About Epson Stilus Color 670 --or-- Setting up print filters
Printing Trouble in Linux

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Programming in Other Languages

Fortran Compiler

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Python Programming

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Scientific Computing

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Security

"crypt" function in Linux
linux question
Piercing the Veil (ssh NAT/Firewall Piercing Trick)
Closing Ports
Confused About Internet Access to My Home Computer --or-- Does Internet access require an ISP?
ACLs on Linux
Login as root problem --or-- Remote Login as 'root': Don't do it! (Except using SSH or ...)
"harden" Linux DNS server --or-- "Hardening" a Red Hat (into a Helmet?)
Open ports --or-- Closing Ports, Disabling Unwanted Services
RedHat Login Problems --or-- login, su, and passwd dies: Everybody dies!
PAM applications running as root (Was Re: WebTrends Enterprise Reporting Server)
Limiting Internet Access through Cable Modems

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Shell Scripting

Bash
Search and Replace Without Breaking Permissions
Tips: Yet another way to find
script --or-- parsing files with Bash
netscape bash function script
login script --or-- "Unary Command Expected" in Shell Script
Embedding Newlines in Shell and Environment Values
Readline Features in the Bash 'read' built-in
Extracting a block of text from a file
shell cannot see an existing file --or-- ./script: No such file or directory
co-processes --or-- zsh Co-processes
More on: Shell Variable Scoping
Linux read --or-- a problem with pipes in ksh
Simple shell and cron question shell script
Comparing files locally to those on an FTP server
Random Numbers --or-- Getting Random Values in sh
Scripting and Programming (including Startup Scripts)

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Sound

More help with Linux Multimedia
Sweet Music?

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Switching from Other Operating Systems

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System Administration

Password aging
setting root password
Scheduling 3rd party services --or-- Cron
Is there any.. --or- Syslog Events from a Particular Host to a Particular File
Simple Shell and Cron Question
Linux password lost --or-- Lost Password
multiple root accounts --or-- Multiple Root Accounts: Delegation

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System Configuration

serial consoles, install, boot, etc --or-- Serial Consoles
Linux, Laptops, and Cooling Fans --or-- Making the Laptop's Fan Run
International Keyboard Mappings for

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System Startup: After the Boot up to the Login Prompt

virtual console login --or-- Console Logins Fail; KDM Okay?
The Linux Startup Script?
Maximal mount reached; check forced --or-- Maximal Mount Count Reached

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The Answer Guy's Most Memorable Rants

question on trees --or-- Another Homework Assignment from Hotmail
unable to open a initial console --or-- A Short Guide on How to do Backups and Recovery

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The Kernel

Linux Kernel Crashdumps: HOW?
Modules cannot load with kernel recompile
Comments to "A rather unique query (I hope)" --or-- symlink considered harmful
Segmentation Faults --or-- General S. Fault
Linux memory management --or-- Homework Assignment: Write about Linux Memory Management

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UNIX Commands

Q: avoid getting answers from apropos in the man sections 3 and 3x
about Unix command rm
Dash it All! Coping with ---Unruly--- Filenames
question on rm command --or-- Homework Answer: All about 'rm'
reverse dns
a quick question --or-- DIR /S
Why is diff so crazy?
unix system admin --or-- Getting Familiar with a UNIX System
about Unix command rm
control another VT? --or-- Temporarily Controlling a VT

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Uninstalling Linux

Removing Linux: Sacrilege!
Another uninstall: Getting to a Root Prompt to Blow it All Away
Uninstall Linux --or-- Uninstalling Linux
Left in the Lurch or: Uninstalling Linux the Hard Way

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Video Cards

Installing RedHat 7.0 and a driver for the Chipset Cirrus CL-GD5436
Linux, X, Dell Video Card
Trident Providia 9685
graphic chipset Linux/CA-810 --or-- Linux on an Intel "Camino" CA810 Motherboard
Intel's integrated Chipset --or-- Identifying the Integrated Video Chipset
driver d'installazione --or- SIS 6236
X Server --or-- Jaton 107 Blade 3D and XFree86
Driver for Savage 4 pro --or-- Savage 4 Pro

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[ This part was incorporated from the LG-FAQ and expanded. ]

1. How can I get help on Linux?

Check the FAQ. (Oh, you already are. :)) Somewhat more seriously, there is a Linux FAQ located at http://www.linuxdoc.org/FAQ/Linux-FAQ/index.html which you might find to be helpful.

For people who are very new to Linux, especially if they are also new to computing in general, it may be handy to pick up one of these basic Linux books to get started:

<plug type="cheap">
Of course, the original Answer Guy himself, Jim Dennis, was a coauthor on Linux System Administration, published by New Riders. It is not an introductory book, but it has a considerable amount of material about the kind of planning system administrators need to do, and the second half delves into deeper topics, so it may help bring a broader understanding.
</plug>

Mailing lists exist for almost every application of any note, as well as for the distributions. If you get curious about a subject, and don't mind a bit of extra mail, sign onto applicable mailing lists as a "lurker" -- that is, just to read, not particularly to post. At some point it will make enough sense that their FAQ will seem very readable, and then you'll be well versed enough to ask more specific questions coherently. Don't forget to keep the slice of mail that advises you how to leave the mailing list when you tire of it or learn what you needed to know.

You may be able to meet with a local Linux User Group, if your area has one. There seem to be more all the time -- if you think you may not have one nearby, check the local university or community college before giving up.

And of course, there's always good general resources, such as Linux Gazette :) Send all questions and answers to The Answer Gang <>. Several volunteers will try to respond to them via e-mail. All questions and answers will be considered for publication in the next issue of Linux Gazette, and those chosen will be grouped into threads and put in the Answer Gang, 2-Cent Tips or Mailbag column. Generally, short answers and tips go into 2-Cent Tips, long answers or those with multiple respondents go into The Answer Gang, and a limited selection of the questions for which we have no adequate answer will go into the Mailbag along with suggestions for future articles. Questions and answers about the Gazette itself will be in the Gazette Matters section of the Mailbag.

The Answer Gang can answer short, specific questions that will be of interest to a significant portion of our readership. (All questions and answers are considered for publication, although you can be anonymous if you request.) However, for large, general question like "help me design my office network" or "write me an application which does this", we would steer you to the Linux documentation and to paid consultants.

We don't guarantee that your question sent to TAG will ever be answered ! If you don't see any reply, keep paying attention to the published version of LG because your answer may show up as the reply to someone else's question.

You might want to check the Answer Gang Index and see if your question got asked before. The older a question is, the greater the chance that the answer needs updating, but it's a start.

2. Can I run Windows applications under Linux?

An excellent summary of the current state of:

...was in issue #44, The Answer Guy, "Running Win '95 Apps under Linux".

There is also a program called VMware (www.VMWare.com) which lets you run several "virtual computers" concurrently as applications, each with its own Operating System. There is a review in Linux Journal about it.

You might consider Bochs (www.bochs.com), which also works on non-Intel hardware and the BSD family.

3. Do you answer Windows questions too?

Some of them.

Answers in either the Tips or Answer Guy columns which relate to troubleshooting hardware, might be equally valuable to Linux and Windows users. This is however Linux Gazette... so all the examples are likely to describe Linux methods and tools.

The Answer Guy has ranted about this many times before. He will gladly answer questions involving getting Linux and MS Windows systems to interact properly; this usually covers filesystems, use of Samba (shares) and other networking, and discussion of how to use drivers.

However, if your question only involves Windows, this is not the best place to ask. The Answer Guy hasn't used Windows in many years, and in fact typically avoids the graphical user interfaces available to Linux as well. That we've grown up into an Answer Gang isn't worth much for Windows only questions either -- only a few of us have any notable experience with Windows, and for those of us that do, a lot of it is quite out of date.

Maybe you should try the websites for the various Windows magazines -- many of them offer an open forum. You could even (gasp) use the tech support that was offered with your commercial product. Also, there are newsgroups for an amazing variety of topics, including MS Windows.

4. How do I find the help files in my Linux system?

The usual command to ask for a help page on the command line is the word man followed by the name of the command you need help with. You can get started with man man. It might help you to remember this, if you realize it's short for "manual."

A lot of plain text documents about packages can be found in /usr/doc/packages/<packagename>, /usr/doc/<packagename>, or /usr/share/doc/<packagename>in modern distributions. If you installed them, you can also usually find the FAQs and HOWTOs installed in the above directories as ../FAQ and ../HOWTO respectively.

Some applications have their own built-in access to help files (even those are usually text stored in another file, which can be reached in other ways). For example, pressing F1 in vim, ? in lynx, or ctrl-H followed by a key in Emacs, will get you into their help system. These may be confusing to novices, though.

Many programs provide minimal help about their command-line interface if given the command-line option --help, -h or -?. Even if these don't work, most give a usage message if they don't understand their command-line arguments. The GNU project has especially followed through with this idea. It's a good one; every programmer creating a small utility should have it self-documented at least this much.

Graphical interfaces such as tkman and tkinfo will help quite a bit because they know where to find these kinds of help files; you can use their menus to help you find what you need. The better ones may also have more complex search functions.

Some of the bigger distributions link their default web pages to HTML versions of the help files. They may also have a link to help directly from the menus in their default X Windowing setup. Therefore, it's wise to install the default window manager, even if you (or the friend helping you) have a preference for another one, and to explore its menus a bit.

There's a fellow who has a searchable website filled with manpages at http://linux.ctyme.com/.

5. So I'm having trouble with this internal modem...

It's probably a winmodem. Winmodems suck for multiple reasons:

  1. Most of them lack drivers for Linux. Notice the term "most" and not "all" -- see http://linmodems.org for more about those few that do, and some general knowledge on the subject. Last time we looked (Issue 63, "State of the Art in Softmodems") only four models had any support, and only two had vendor help.
  2. Since they aren't a complete modem without software, even if they were to work under Linux, they'd eat extra CPU that could be better spent on other things. So they'll never seem quite as fast as their speed rating would imply.
  3. Internal modems (even those which bear complete chipsets) have their own problems; they overheat more easily, and have a greater danger of harming other parts in your system when they fail, merely because they're attached directly to the bus. The tiny portion of speed increase that might lend is not really worthwhile compared to the risk of losing other parts in the system.

So, yeah, there can be good internal modems, but it's more worthwhile to get an external one. It will often contain phone line surge suppression and that may lead to more stable connections as well.

This page is copyright by its contributors and the Editors of Linux Gazette,
Copyright © 1999-2001, Specialized Systems Consultants, Inc.,

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