OReilly linux cookbook nov 2004 ISBN 0596006403

Publisher : O'ReillyPub Date : November 2004ISBN : 0-596-00640-3Pages : 580 Linux information can be found scattered in man pages, texinfo files, and source code comments, but the best s

Publisher : O'ReillyPub Date : November 2004ISBN : 0-596-00640-3Pages : 580

Linux information can be found scattered in man pages, texinfo files, and source code comments, but the best source is the experts who have built up a working knowledge of managing

Linux systems The Linux Cookbook's tested techniques distill

years of hard-won experience into practical cut-and-paste solutions to everyday Linux dilemmas Use just one recipe from this collection of real-world solutions, and the hours of tedious trial-and-error saved will more than pay for the cost of the book It's more than a time-saver; it's a sanity saver.

Publisher : O'ReillyPub Date : November 2004ISBN : 0-596-00640-3Pages : 580

Printed in the United States of America

Published by O'Reilly Media, Inc., 1005 Gravenstein HighwayNorth, Sebastopol, CA 95472

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While every precaution has been taken in the preparation of thisbook, the publisher and author assume no responsibility for

errors or omissions, or for damages resulting from the use ofthe information contained herein

To Dawn Marie.

During the writing of this book, she tilled the fields, trained the horses, cooked the meals, cleaned the ditches, and graciously fended off generous neighbors bearing large zucchinis No

author could ask for more Thank you for 14 great years; may

we have many more.

So: you're a relatively new Linux user You've got Linux

installed, you've managed to log in, do some web browsing,send and receive email, andnow what? Although you can handlesome of the basics, you feel like you're flying blind: you knowyou've got lots of really powerful stuff at your fingertips, or atleast so your Linux guru friend told you, but how do you make it

do tricks? What's there, and how does it work? What's this thingcalled grep that they're always talking about? How do you

Samba? And where's the #$%^ documentation?

The Linux-Unix world is abundantly documented No, really! Youcan always find an answer, if you know where to look The

problem, of course, is knowing where to look There are manpages, info pages, READMEs, HTML manuals, and the code

itself You don't have to be a programmer to unearth useful bits

in source code, because the comments often tell you what youneed to know

There are thousands upon thousands of online communities,one (or more) surrounding nearly every bit of software in theLinux universe Nearly every program, no matter how small,has its own user mailing list Every Linux distribution has itsown mailing lists and user forums There are forums and listsand Usenet groups for every computing subject under the sun

And of course there are books and magazines of every

description So the real problem with Linux documentation isnot the lack of it, but finding the bits you need without having

to embark on a lengthy, heroic quest

This book is aimed at folks who want to know what button topush Understanding the underlying theory is useful, but if youcan't make the darn thing work, not very helpful So it's light ontheory and heavy on how-to-make-this-go, with detailed, step-by-step instructions I've included many references to additionalresources

Readers should have a bit of Linux experience You don't need

to be a guru, but you should have some familiarity with the

basics of booting up and shutting down, starting applications,Web surfing, and poking around the filesystem You should

know how to find and use the command line, as well as work in

a graphical environment You should understand that Linux is atrue multi-user system, and that you use an ordinary

unprivileged user account as much as possible, and that youonly invoke root when you really need to

This book assumes that you are in charge of a PC or LAN, andcan acquire rootly powers when the occasion calls for them Youmight be a power user who wants complete control of your

Linux box, or a home user who wants to run a personal web ormail server, or set up a small LAN Perhaps you are a Windowssystem admininstrator who has suddenly been ordered to "doLinux," and you need to know how to set up Linux servers forWindows clients Maybe you want to add Linux servers to anexisting network You might need to integrate Linux and

Windows desktop users on a LAN

Or you have no need for Windows at all, and just want to learnLinux system administration

Given that there are thousands of software packages to choosefrom, almost all of which do something useful, it was a foregoneconclusion that I couldn't cover everything Or even most ofeverything I decided what to include, and what to leave out,based on my opinion of what a fundamental Linux skill set

should include (You may have different ideas.) I included

programs that I consider to be the best-of-breed, such djbdns,GRUB, Apache 2, vim, and Postfix And I didn't neglect old

Linux system, it will take you anywhere you want to go

There are more Linux distributions than can be counted; thereare literally thousands of distributions, many of which are

peculiar to a company, a campus, or even a circle of friends wholike to roll their own However, the world of distributions breaks(not very cleanly) into two large camps: RPM-based systems,represented in this book by Red Hat and Fedora, and apt-basedsystems, represented by Debian Debian-based distributions arespreading like weeds, such as Knoppix, Xandros, Libranet,

Unbuntu, and Linspire

Even if you are using a distribution that does not fall into one ofthese two categories, such as Slackware or Gentoo, the

fundamentals are pretty much the same The kernel is the

same; the programs and utilities available are the same; thewindow managers are the same; the only substantial difference

is the way you install software

That's not to say there aren't other differences between Linuxdistributions A chronic bugaboo with Linux is differing file

locations on different distributions Get used to it; it's not going

to go away This book provides several excellent methods forfinding out where your particular distribution puts configurationfiles, executables, and program documentation

One particularly important convention in this book involves theuse of command line prompts I can't say it too often: don't getinto the habit of su'ing to root whenever you have to do

anything remotely administrative Even worse, don't say "It's

my machine, I can do anything as root." Use root privilegesonly when you really need them You'll be safer that way; you'llhave some protection against your own mistakes, and againstattacks made by outsiders

To show you when you need root privileges, commands

requiring root privileges are preceded by the root prompt, #.Commands that don't require root privileges are preceded bythe default bash shell prompt, $

Don't be confusedthere are many file listings in the book, and inmany of these files, comments are preceded by # Yes, it can

be confusing, but you'll get used to it

Doubtless this book, despite the heroic efforts of me and thefabulous O'Reilly team, contains flaws, errors, and omissions.Please email your feedback and suggestions to

cookbook@bratgrrl.com, so we can make the second editioneven better Be sure to visit http://tuxcomputing.com for

errata, updates, and to download the scripts and configurationfiles used in the book

This book was authored entirely in Open Office Writer, on

Libranet Debian 2.8

Please address comments and questions concerning this book tothe publisher:

To comment on or ask technical questions about this book, sendemail to:

bookquestions@oreilly.com

For more information about books, conferences, software,

Resource Centers, and the O'Reilly Network, see the O'Reillyweb site at:

http://www.oreilly.com

Thank you to ace O'Reilly editor Michael Loukides, whose goodtaste, eagle editorial eye, patient endurance, and implacableinsistence made this a much better book

Thank you to ace technical reviewer Jenn Vesperman, and herattention to detail Silly computers are completely literal, andmust be fed precise inputthanks Jenn!

Many thanks to Akkana Peck, Jenn Vesperman, Paul Heinlein,and Peter Samuelson, whose contributions appear in this book.Heartfelt thanks to the gang at Linuxchix, including Jenn

Vesperman (benevolent dictator of Linuxchix), Dancer

Vesperman, Danamania (the camera does not lie), Colby,

Evilpig, Almut Behrens, Andrew (Mandrake Guru), Hamster,Piglet, Val Henson (uppity rabble rouser), H Peter Anvin (kernelguru and rabbit rouser), Rik Rose, Devdas Bhagat, David North(for comic relief), Telsa Gwynne, Maria Blackmore, MeredyddLuff, Kai MacTane, and Erinn Clark (for more uppity rabble-

rousing) Linuxchix rawks!

I'm sure I missed some folks who patiently endured my endlesspestering Tell me who you are, and I'll fix it in the second

edition

Documentation for Linux programs is abundant Finding it can

be a bit challenging, though You're not going to find lots ofsleek, glossy printed manuals, because most Linux software isdistributed online, rather than in shiny boxed sets

There's another difficulty, too: Linux follows the grand Unix

tradition of small, specialized programs working cooperatively,

so any Linux distribution contains a large number of individualprograms For example, Tom's Root Boot, "The most GNU/Linux

on one floppy disk," contains over 230 separate, individual

programs on a single 3.5" diskette A general-purpose

distribution such as Mandrake or SuSE contains several

thousand programs and there are over 12,000 packages in theDebian repositories While organizing and maintaining a printedlibrary presents some difficulties, the good news is that all ofthese things are documented Whatever you want to know,

there is a way to find it

1.1.1 man and info: The Universal Linux Manuals

Almost every program written for Linux has a man page.

They're usually not the best teaching tool for newbies Theirpurpose is to document the command syntax and every

command option, and to be universally available No matterwhat kind of strange desert-island scenario you may find

yourself in, there will always be man pages And because manpages are incorporated into the programs to which they belong,you'll find that only installed programs have man pages andthat the versions of those pages are pertinent to your system

info pages tend to be more verbose than man pages and are

hyperlinked The hyperlinks navigate to the various nodes, or

1.1.2 Other Documentation

A large number of README, CHANGELOGS, RELEASE NOTES,COPYRIGHT, INSTALL, integrated Help systems, and HTML docsare going to be squirreled away in various locations on yoursystem Yes, it's a jumble Don't worry, you'll learn easy ways

to find all these things in this chapter, including a nice Pythonscript to do the finding for you

There are many web sites that host complete archives of manand info pages, which comes in handy if your system is missingthe ones you want, or you want to read them without having todownload and install new programs A Google search will findthem quickly

The commercial Linux distributionsfor example, Red Hat, SuSE,Mandrake, Xandros, and Linspiresupply excellent user manuals.Every major Linux distribution provides a feast of online

resources Search engines, user mailing lists, Usenet, and allsorts of Linux web sites also supply a wealth of help and

information

1.1.3 Graphical Viewers

There are several good graphical man and info page viewers:

Konqueror

man and info page viewer Simply type man:foo or info:/foo

in the address bar It is easy to print from Konqueror, andeasy to select individual man or info pages for printing

Learn how man pages are organized, and familiarize yourselfwith their conventions for teaching command syntax and

options, and you'll find that man pages really are helpful

1.2.3 Discussion

Linux sees all the man pages on a system as part of a singlemanual This manual is divided into sections:

OPTIONS, FILES, EXAMPLES, SEE ALSO, BUGS, and AUTHOR

Here's the notation used to show command syntax, found in theSynopsis of the man pages:

command-name [optional flags] any-other-required-elements

Everything inside square brackets is optional and can becombined

[-a|-b|-c]

Options separated by the pipe | (Shift-backslash) cannot becombined

argument

The ellipsis indicates that several arguments can be listed.Watch out for delimitersusually they are spaces, but

sometimes commas are used

pwconv (8) - convert to and from shadow passwords and groups

apropos(1), man(1)

.SH SYNOPSIS

.B cat

1.5.4 See Also

mandb(8), locate(1), grep(1), nroff(1), groff(1), zless(1), zcat(1)

Recipe 1.6

Chapter 9 of Running Linux, by Matt Walsh, Matthias

Dalheimer, Terry Dawson, and Lar Kaufman (O'Reilly)

1.6.1 Problem

You're repeatedly having trouble finding man pages; using toolsfrom Recipe 1.4, you find that most of the missing pages are in

You can run manpath with no options to see your current

manpaths:

/usr/local/man:/usr/share/man:/usr/X11R6/man:/usr/man

1.6.4 See Also

manpath(1), manpath(5)

1.7.3 Discussion

Even though some folks think that info pages are unnecessarilycomplicated to navigate, it is worth getting acquainted with

them Even though they are more difficult to navigate than manpages, they are (usually) easier to understand Once you getthe hang of moving around in them, you can go very fast andfind information quickly Info pages often contain more

information than man pages, and they sometimes include

tutorials and extensive examples

There are also a number of nice info viewers, such as pinfo,

Konqueror, and Yelp Pinfo runs in the console, and Konquerorand Yelp need X Konqueror is especially easy to navigate and

to use for printing selected pages

info info

1.8.1 Problem

You want to print a man page, nicely formatted and readable You have tried man foo | lpr, but it doesn't look very good The

margins are too small, and all the formatting is lost

1.8.2 Solution

One way to print a nicely formatted man page is to use the -t flag, which formats it especially for printing man finger is good

choice:

Recipe 1.10 Printing Selected man or info Pages 1.10.1 Problem

of reverse line feeds, which then appear in text files as eitherempty boxes or repeated characters

col(1)

Recipe 1.11 Finding All of the Documentation for a Program

1.11.1 Problem

You want to find all the relevant readmes, changelogs, howtos,guides, examples, samples, and other documentation that

]

#print path

if (re.compile(nam).search(base, 1)) : print path,

Recipe 2.8 Rebuilding the RPM Database

Based System

Recipe 2.9 Tracking Source-Built Libraries on an RPM-Recipe 2.10 Fixing RPM Installation Problems

Recipe 2.11 Installing Source RPMs

Recipe 2.12 Customizing Build Options in a Source RPMRecipe 2.13 Installing Yum

Recipe 2.14 Configuring Yum

Recipe 2.15 Installing and Upgrading Packages with YumRecipe 2.16 Removing Packages with Yum