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Title: Debian GNU/Linux : Guide to Installation and Usage
Author: Goerzen and Othman
Release Date: September, 2004 [EBook #6527]
[Most recently updated: July 13, 2020]
Language: English
Character set encoding: UTF-8
*** START OF THIS PROJECT GUTENBERG EBOOK DEBIAN GNU/LINUX: GUIDE TO INSTALATION AND USAGE ***
Debian GNU/Linux: Guide to Installation and Usage
by John Goerzen and Ossama Othman
April 23, 2001
(c) 1998, 1999 Software in the Public Interest, Inc.
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided also
that the sections that reprint “The GNU General Public License” and
other clearly marked sections held under separate copyright are
reproduced under the conditions given within them, and provided that
the entire resulting derived work is distributed under the terms of
a permission notice identical to this one.
Permission is granted to copy and distribute translations of this
manual into another language under the conditions for modified
versions. “The GNU General Public License” may be included in a
translation approved by the Free Software Foundation instead of in
the original English.
At your option, you may distribute verbatim and modified versions of
this document under the terms of the GNU General Public License,
excepting the clearly marked sections held under separate copyright.
Contents
List of Figures
List of Tables
Acknowledgments
Preface
I. Guide
1. Introduction
1.1 What Is Debian?
1.2 A Multiuser, Multitasking Operating System
1.3 What Is Free Software?
1.4 About This Book
2. Getting Started
2.1 Supported Hardware
2.2 Before You Start
2.3 Partitioning Your Hard Drive
2.4 Choosing Your Installation Media
2.5 Booting the Installation System
3. Step-by-Step Installation
3.1 Select Color or Monochrome Display
3.2 Debian GNU/Linux Installation Main Menu
3.3 Configure the Keyboard
3.4 Last Chance to Back Up!
3.5 Partition a Hard Disk
3.6 Initialize and Activate a Swap Partition
3.7 Initialize a Linux Partition
3.8 Install Operating System Kernel and Modules
3.9 Configure PCMCIA Support
3.10 Configure Device Driver Modules
3.11 Configure the Network
3.12 Install the Base System
3.13 Make a Boot Floppy
3.14 The Moment of Truth
3.15 Set the Root Password
3.16 Create an Ordinary User
3.17 Shadow Password Support
3,18 Remove PCMCIA
3.19 Select and Install Profiles
3.20 Package Installation with dselect
3.21 Glossary
4. Logging In
4.1 First Steps
4.2 Command History and Editing the Command Line
4.3 Working as Root
4.4 Virtual Consoles
4.5 Shutting Down
5. The Basics
5.1 The Command Line and Man Pages
5.2 Files and Directories
5.3 Processes
5.4 The Shell
5.5 Managing Processes with bash
5.6 A Few bash Features
5.7 Managing Your Identity
6. Using the Shell
6.1 Environment Variables
6.2 Where Commands Reside: The PATH Variable
6.3 Configuration Files
6.4 Aliases
6.5 Controlling Input and Output
6.6 Filename Expansion
7. More on Files
7.1 Permissions
7.2 Files Present and Their Locations
7.3 File Compression with gzip
7.4 Finding Files
7.5 Determining a File’s Contents
7.6 Using a File Manager
8. Working with Text Files
8.1 Viewing Text Files
8.2 Text Editors
8.3 Using ae
9. The X Window System
9.1 Introduction to X
9.2 Starting the X Environment
9.3 Basic X Operations
9.4 Customizing Your X Startup
10. Filesystems
10.1 Concepts
10.2 mount and /etc/fstab
10.3 Backup Tools
11 Networking
11.1 PPP
11.2 Ethernet
12 Removing and Installing Software
12.1 What a Package Maintenance Utility Does
12.2 dpkg
12.3 dselect
12.4 Compiling Software
13 Advanced Topics
13.1 Regular Expressions
13.2 Advanced Files
13.3 Security
13.4 Software Development with Debian
II. Reference
A Reading Documentation and Getting Help
A.1 Kinds of Documentation
B Troubleshooting
B.1 Common Difficulties
B.2 Troubleshooting the Boot Process
C Booting the System
D The GNU General Public License
List of Figures
1. cfdisk screenshot
2. dselect Access screen
3. Sample session with su
4. Sample printenv output
5. Changing the prompt
6. Redirecting output
List of Tables
1. Linux Device Names
2. Special dselect keys
3. dselect Package States
4. Expected Package Category States
5. Permissions in Linux
Acknowledgments
Many people have helped with this manual. We’d like to thank
everyone involved, and we try to do that here.
Thanks to Havoc Pennington, Ardo van Rangelrooij, Larry Greenfield,
Thalia Hooker, Day Irmiter, James Treacy, Craig Sawyer, Oliver
Elphick, Ivan E. Moore II, Eric Fischer, Mike Touloumtzis, and the
Linux Documentation Project for their work on what became the Debian
Tutorial document.
Thanks to Richard Stallman of the Free Software Foundation for
advice and editing.
Thanks to Bruce Perens, Sven Rudolph, Igor Grobman, James Treacy,
Adam Di Carlo, Tapio Lehtonen, and Stephane Bortzmeyer for their
work on what became a collection of installation documents.
Of course, it’s impossible to thank the hundreds of Debian
developers and thousands of free software authors who gave us
something to write about and use.
Preface
_“Freedom is still the most radical idea of all.”_
This quote, penned by Nathaniel Branden, seems fitting nowhere
moreso than with the freewheeling computing industry. In the space
of just a few decades, lives the world over have been changed by
computing technology. We, the people behind the Free Software
movement, are seeking to continue this trend by truly opening up
software to everyone—not just the few people working for the
companies that write it—but everyone. As part of this goal, this
book and CD contain a treasure chest of Free Software. Over one
thousand packages, including things such as the world’s most popular
web server, can be found here. You can use this software for
everything from graphic design to SQL databases.
The Free Software revolution has taken the industry by storm. Linux,
started from scratch not even 10 years ago, has been the favorite
kernel of the Free Software world. The ideas and experience gained
from Free Software have truly sent Linux and the Free Software
Foundation’s GNU tools all over the world. Free systems such as
Debian GNU/Linux ship with literally thousands of applications, and
they have more power and stability, and outperform some of the
industry’s traditional best-selling proprietary operating systems.
Today, GNU/Linux plays a dominant role in Internet servers and among
ISPs, in academia, among computer hobbyists, and in computer science
research. Debian GNU/Linux has brought the power of Free Software to
everything from laptops to flights aboard the Space Shuttle. As I
write this, companies the world over are experiencing the joy and
benefits that are Free Software. The unprecedented power, the
ability to speak directly to the people who write the software you
use, the capability to modify programs at will, and the phenomenal
expertise of the online support mechanism all combine to make Free
Software a vibrant and wonderful way to use your computing
resources.
Starting with a Free Software such as Debian GNU/Linux can be the
best thing you’ve done with your computer in a long time. It’s fast,
powerful, stable, versatile, and _fun_!
Welcome to the revolution!
— John Goerzen
I. Guide
1. Introduction
We’re glad to have this opportunity to introduce you to Debian! As
we begin our journey down the road of GNU/Linux, we’d like to first
talk a bit about what exactly Debian is—what it does, and how it
fits in with the vast world of Free Software. Then, we talk a bit
about the phenomenon that is Free Software and what it means for
Debian and you. Finally, we close the chapter with a bit of
information about this book itself.
1.1 What Is Debian?
_Debian_ is a free operating system (OS) for your computer. An
operating system is the set of basic programs and utilities that
make your computer run. At the core of an operating system is the
_kernel_. The kernel is the most fundamental program on the
computer: It does all the basic housekeeping and lets you start
other programs. Debian uses the _Linux_ kernel, a completely free
piece of software started by Linus Torvalds and supported by
thousands of programmers worldwide. A large part of the basic tools
that fill out the operating system come from the GNU Project[1], and
these tools are also free.
[1]
http://www.gnu.org/
Another facet of an operating system is application software:
programs that help get work done, from editing documents to running
a business to playing games to writing more software. Debian comes
with more than 1,500 _packages_ (precompiled software bundled up in
a nice format for easy installation on your machine)—all for free.
The Debian system is a bit like a pyramid. At the base is Linux. On
top of that are all the basic tools, mostly from GNU. Next is all
the application software that you run on the computer; many of these
are also from GNU. The Debian developers act as architects and
coordinators—carefully organizing the system and fitting everything
together into an integrated, stable operating system: Debian
GNU/Linux.
The design philosophy of GNU/Linux is to distribute its
functionality into small, multipurpose parts. That way, you can
easily achieve new functionality and new features by combining the
small parts (programs) in new ways. Debian is like an erector set:
You can build all sorts of things with it.
When you’re using an operating system, you want to minimize the
amount of work you put into getting your job done. Debian supplies
many tools that can help, but only if you know what these tools do.
Spending an hour trying to get something to work and then finally
giving up isn’t very productive. This guide will teach you about the
core tools that make up Debian: what tools to use in certain
situations and how to tie these various tools together.
1.1.1 Who Creates Debian?
Debian is an all-volunteer Internet-based development project. There
are hundreds of volunteers working on it. Most are in charge of a
small number of software packages and are very familiar with the
software they package.
These volunteers work together by following a strict set of
guidelines governing how packages are assembled. These guidelines
are developed cooperatively in discussions on Internet mailing
lists.
1.2 A Multiuser, Multitasking Operating System
As we mentioned earlier in section 1.1, the design of Debian
GNU/Linux comes from the Unix operating system. Unlike common
desktop operating systems such as DOS, Windows, and MacOS, GNU/Linux
is usually found on large servers and _multiuser_ systems.
This means that Debian has features those other operating systems
lack. It allows a large number of people to use the same computer at
once, as long as each user has his or her own _terminal_.[2] To
permit many users to work at once, Debian must allow many programs
and applications to run simultaneously. This feature is called
_multitasking_.
[2] A terminal is just a keyboard and a screen that are connected to
the computer through the network, over a modem, or directly. You
keyboard and monitor form a terminal that is directly attached to the
computer: This special terminal is often called the _console_.
Much of the power (and complexity) of GNU/Linux systems stems from
these two features. For example, the system must have a way to keep
users from accidentally deleting each other’s files. The operating
system also must coordinate the many programs running at once to
ensure that they don’t all use the same resource, such as a hard
drive, at the same time.
If you keep in mind what Debian was originally designed to do, many
aspects of it will make a lot more sense. You’ll learn to take
advantage of the power of these features.
1.3 What Is Free Software?
When Debian developers and users speak of “Free Software,” they
refer to _freedom_ rather than price. Debian is free in this sense:
You are free to modify and redistribute it and will always have
access to the source code for this purpose. The Debian Free Software
Guidelines[3] describe in more detail exactly what is meant by
“free.” The Free Software Foundation[4], originator of the GNU
Project, is another excellent source of information. You can find a
more detailed discussion of free software on the Debian web site[5].
One of the most well-known works in this field is Richard M.
Stallman’s essay, _Why Software Should Be Free_[6]; take a look at
it for some insight into why we support Free Software as we do.
Recently, some people have started calling Free Software “Open
Source Software”; the two terms are interchangable.
[3]
http://www.debian.org/social_contract#guidelines
[4]
http://www.fsf.org/
[5]
http://www.debian.org/
[6]
http://www.fsf.org/philosophy/shouldbefree.html
You may wonder why would people spend hours of their own time
writing software and carefully packaging it, only to give it all
away. The answers are as varied as the people who contribute.
Many believe in sharing information and having the freedom to
cooperate with one another, and they feel that free software
encourages this. A long tradition that upholds these values,
sometimes called the Hacker[7] Ethic, started in the 1950s. The
Debian GNU/Linux Project was founded based on these Free Software
ethics of freedom, sharing, and cooperation.
[7] Note that the term “hacker” should not be confused with the term
“cracker.” In short, a hacker is benevolent, whereas a cracker is
generally considered malevolent. Movies and other forms of media many
times incorrectly use the term “hacker” instead of “cracker.”
Others want to learn more about computers. More and more people are
looking for ways to avoid the inflated price of proprietary
software. A growing community contributes in appreciation for all
the great free software they’ve received from others.
Many in academia create free software to help get the results of
their research into wider use. Businesses help maintain free
software so they can have a say in how it develops—there’s no
quicker way to get a new feature than to implement it yourself or
hire a consultant to do so! Business is also interested in greater
reliability and the ability to choose between support vendors.
Still others see free software as a social good, democratizing
access to information and preventing excessive centralization of the
world’s information infrastructure. Of course, a lot of us just find
it great fun.
Debian is so committed to free software that we thought it would be
useful if it was formalized in a document of some sort. Our Social
Contract[8] promises that Debian will always be 100% free software.
When you install a package from the Debian main distribution, you
can be sure it meets our Free Software Guidelines.
[8]
http://www.debian.org/social_contract
Although Debian believes in free software, there are cases where
people want to put proprietary software on their machine. Whenever
possible Debian will support this; though proprietary software is
not included in the main distribution, it is sometimes available on
the FTP site in the non-free directory, and there is a growing
number of packages whose sole job is to install proprietary software
we are not allowed to distribute ourselves.
It is important to distinguish _commercial_ software from
_proprietary_ software. Proprietary software is non-free software;
commercial software is software sold for money. Debian permits
commercial software, but not proprietary software, to be a part of
the main distribution. Remember that the phrase “free software” does
not refer to price; it is quite possible to sell free software. For
more clarification of the terminology, see
http://www.opensource.org/or
http://www.fsf.org/philosophy/categories.html.
1.4 About This Book
This book is aimed at readers who are new to Debian GNU/Linux. It
assumes no prior knowledge of GNU/Linux or other Unix-like systems,
but it does assume very basic general knowledge about computers and
hardware; you should know what the basic parts of a computer are,
and what one might use a computer to do.
In general, this tutorial tries to help you understand what happens
inside a Debian system. The idea is to empower you to solve new
problems and get the most out of your computer. Thus there’s plenty
of theory and fun facts thrown in with the “How To” aspects of the
manual.
We’d love to hear your comments about this book! You can reach the
authors at
[email protected]. We’re especially interested in
whether it was helpful to you and how we could make it better.
Whether you have a comment or think this book is the greatest thing
since sliced bread, please send us e-mail.
Please do not send the authors technical questions about Debian,
because there are other forums for that; see Appendix A on page [*]
for more information on the documentation and getting help. Only
send mail regarding the book itself to the above address.
1.4.1 How to Read This Book
The best way to learn about almost any computer program is by using
it. Most people find that reading a book without using the program
isn’t beneficial. The best way to learn about Unix and GNU/Linux is
by using them. Use GNU/Linux for everything you can. Feel free to
experiment!
Debian isn’t as intuitively obvious as some other operating systems.
You will probably end up reading at least the first few chapters of
this book. GNU/Linux’s power and complexity make it difficult to
approach at first, but far more rewarding in the long run.
The suggested way to learn is to read a little, and then play a
little. Keep playing until you’re comfortable with the concepts, and
then start skipping around in the book. You’ll find a variety of
topics are covered, some of which you might find interesting. After
a while, you should feel confident enough to start using commands
without knowing exactly what they do. This is a good thing.
Tip: If you ever mistakenly type a command or don’t know how to
exit a program, press CTRL-c (the Ctrl key and the lowercase
letter c pressed simultaneously). This will often stop the
program.
1.4.2 Conventions
Before going on, it’s important to be familiar with the
typographical conventions used in this book.
When you should simultaneously hold down multiple keys, a notation
like CTRL-a will be used. This means “press the Ctrl key and press
lowercase letter a.” Some keyboards have both Alt and Meta; most
home computers have only Alt, but the Alt key behaves like a Meta
key. So if you have no Meta key, try the Alt key instead.
Keys like Alt and Meta are called _modifier_ keys because they
change the meaning of standard keys like the letter A. Sometimes you
need to hold down more than one modifier; for example, Meta-Ctrl-a
means to simultaneously press Meta, Ctrl, and lowercase a.
Some keys have a special notation—for example, Ret (Return/Enter),
Del (Delete or sometimes Backspace), Esc (Escape). These should be
fairly self-explanatory.
Spaces used instead of hyphens mean to press the keys in sequential
order. For example, CTRL-a x RET means to simultaneously type Ctrl
and lowercase a, followed by the letter x, followed by pressing
Return. (On some keyboards, this key is labeled Enter. Same key,
different name.)
In sample sessions, bold face text denotes characters typed by the
user, italicized text denotes comments about a given part of the
sample session, and all other text is output from entering a
command. For shorter commands, you’ll sometimes find that the
command can be found within other text, highlighed with a monospace
font.
2. Getting Started
“_A journey of a thousand miles must begin with a single step._”
—Lao-Tsu
Now that you’ve read about the ideas and philosophy behind Linux and
Debian, it’s time to start putting it on your computer! We start by
talking about how to prepare for a Debian install, then about
partitioning your disk, and finally, how to start up the
installation system.
2.1 Supported Hardware
Debian does not impose hardware requirements beyond the requirements
of the Linux kernel and the GNU tools.
Rather than attempting to describe all the different hardware
configurations that are supported for the PC platform, this section
contains general information and pointers to where additional
information can be found.
There are two excellent places to check for detailed information:
the Debian System Requirements[1] list and the Linux Documentation
Project Hardware Compatibility HOWTO[2]. For information on video
card support, you may also want to look at the XFree86[3] Project
web site.
[1]
http://www.debian.org/releases/slink/i386/ch-hardware-req.en.html
[2]
http://metalab.unc.edu/LDP/HOWTO/Hardware-HOWTO.html
[3]
http://www.xfree86.org/
2.1.1 Memory and Disk Space Requirements
You must have at least 4MB of memory and 35MB of available hard disk
space. If you want to install a reasonable amount of software,
including the X Window system, and some development programs and
libraries, you’ll need at least 300MB. For an essentially full
installation, you’ll need around 800MB. To install _everything_
available in Debian, you’ll probably need around 2GB. Actually,
installing everything doesn’t make sense because some packages
provide the same services.
2.2 Before You Start
Before you start, make sure to back up every file that is now on
your system. The installation procedure can wipe out all of the data
on a hard disk! The programs used in installation are quite reliable
and most have seen years of use; still, a false move can cost you.
Even after backing up, be careful and think about your answers and
actions. Two minutes of thinking can save hours of unnecessary work.
Debian makes it possible to have both Debian GNU/Linux and another
operating system installed on the same system. If you plan to use
this option, make sure that you have on hand the original CD-ROM or
floppies of the other installed operating systems. If you
repartition your boot drive, you may find that you have to reinstall
your existing operating system’s boot loader[4] or the entire
operating system itself.
[4] A boot loader is responsible starting an operating system’s boot
procedure.
2.2.1 Information You Will Need
If your computer is connected to a network 24 hours a day (i.e., an
Ethernet or similar LAN connection—not a PPP connection), you should
ask your network’s system administrator for the following
information:
◼ Your host name (you may be able to decide this on your own)
◼ Your domain name
◼ Your computer’s IP address
◼ The IP address of your network
◼ The netmask to use with your network
◼ The broadcast address to use on your network
◼ The IP address of the default gateway system you should route
to, if your network _has_ a gateway
◼ The system on your network that you should use as a DNS server
◼ Whether you connect to the network using Ethernet
◼ Whether your Ethernet interface is a PCMCIA card, and if so, the
type of PCMCIA controller you have
If your only network connection is a telephone line using PPP or an
equivalent dialup connection, you don’t need to worry about getting
your network set up until your system is already installed. See
section 11.1 on page 99 for information on setting up PPP under
Debian.
2.3 Partitioning Your Hard Drive
Before you install Debian on your computer, it is generally a good
idea to plan how the contents of your hard drive will be arranged.
One part of this process involves partitioning your hard drive.
2.3.1 Background
Partitioning your disk simply refers to the act of breaking up your
disk into sections. Each section is then independent of the others.
It’s roughly equivalent to putting up walls in a house; after that,
adding furniture to one room doesn’t affect any other room.
If you already have an operating system on your system (Windows 95,
Windows NT, DOS, etc.) and you want to install Debian GNU/Linux on
the same disk, you will probably need to repartition the disk. In
general, changing a partition that already has a filesystem on it
will destroy any information in that filesystem. Therefore, you
should always make backups before doing any repartitioning. Using
the analogy of the house, you would probably want to move all the
furniture out of the way before moving a wall or you risk destroying
your furniture. Luckily, there is an alternative for some users; see
section 2.3.6 on page [*] for more information.
At a bare minimum, GNU/Linux needs one partition for itself. You can
have a single partition containing the entire operating system,
applications, and your personal files. Most people choose to give
GNU/Linux more than the minimum number of partitions, however. There
are two reasons you might want to break up the filesystem into a
number of smaller partitions. The first is for safety. If something
happens to corrupt the filesystem, generally only one partition is
affected. Thus, you only have to replace (from the backups you’ve
been carefully keeping) a portion of your system. At the very least,
you should consider creating what is commonly called a “root
partition.” This contains the most essential components of the
system. If any other partitions get corrupted, you can still boot
into GNU/Linux to fix the system. This can save you the trouble of
having to reinstall the system from scratch.
The second reason is generally more important in a business setting,
but it really depends on your use of the machine. Suppose something
runs out of control and starts eating disk space. If the process
causing the problem happens to have root privileges (the system
keeps a percentage of the disk away from users), you could suddenly
find yourself out of disk space. This is not good since the
operating system needs to use real files (besides swap space) for
many things. It may not even be a problem of local origin. For
example, unsolicited e-mail (“spam”) can easily fill a partition. By
using more partitions, you protect the system from many of these
problems. Using e-mail as an example again, by putting the directory
/var/spool/mail on its own partition, the bulk of the system will
/work
even if unsolicited e-mail fills that partition.
Another reason applies only if you have a large IDE disk drive and
are using neither LBA addressing nor overlay drivers[5]. In this
case, you will have to put the root partition into the first 1,024
cylinders of your hard drive, usually around 524 megabytes. See
section 2.3.3 on page [*] for more information on this issue.
[5] See your hard drive manual for a description of these features.
Most people feel that a swap partition is also a necessity, although
this isn’t strictly true. “Swap” is scratch space for an operating
system, which allows the system to use disk storage as “virtual
memory” in addition to physical memory. Putting swap on a separate
partition allows Linux to make much more efficient use of it. It is
possible to force Linux to use a regular file as swap, but this is
not recommended.
The only real drawback to using more partitions is that it is often
difficult to know in advance what your needs will be. If you make a
partition too small, either you will have to reinstall the system,
or you will be constantly moving things around to make room in the
undersized partition. On the other hand, if you make the partition
too big, you may be wasting space that could be used elsewhere.
2.3.2 Planning Use of the System
Disk space requirements and your partitioning scheme are influenced
by the type of installation you decide to create.
For your convenience, Debian offers a number of default “profiles”
some of which are listed later in this section. Profiles are simply
preselected sets of packages designed to provide certain desired
capabilities on your system. Installation is easier since packages
that fit your desired profile are automatically marked for
installation. Each given profile lists the size of the resulting
system after installation is complete. Even if you don’t use these
profiles, this discussion is important for planning, since it will
give you a sense of how large your partition or partitions need to
be. The following are some of the available profiles and their
sizes:
Server_std. This is a small server profile, useful for a
stripped-down server, that does not have a lot of niceties for shell
users. It basically has an FTP server, a web server, DNS, NIS, and
POP. It will take up around 50MB. Of course, this is just the size
of the software; any data you serve would be additional.
Dialup. This profile would be good for a standard desktop box,
including the X Window system, graphics applications, sound,
editors, etc. The size of the packages will be around 500MB.
Work_std. This profile is suitable for a stripped-down user machine
without the X Window system or X applications. It is also suitable
for a laptop or mobile computer. The size is around 140MB. It is
possible to have a simple laptop setup including X with less than
100MB.
Devel_comp. This is a desktop setup profile with all the popular
development packages, such as Perl, C, and C++. It requires around
475MB. Assuming you are adding X and some additional packages for
other uses, you should plan for approximately 800MB of disk space
for this type of installation.
Remember that these sizes don’t include all the other materials that
are normally found, such as user files, mail, and data. It is always
best to be generous when considering the space for your own files
and data. Notably, the Debian /var directory contains a lot of state
information. The installed package management files can easily
consume 20MB of disk space. In general, you should allocate at least
50MB for the /var directory because system log files are also stored
there.
2.3.3 PC Disk Limitations
A PC BIOS generally adds additional constraints for disk
partitioning. There is a limit to how many “primary” and “logical”
partitions a drive can contain. Additionally, there are limits to
where on the drive the BIOS looks for boot information. More
information can be found in the Linux Partition mini-HOWTO[6]. This
section will include a brief overview to help you plan most
situations.
[6]
http://metalab.unc.edu/LDP/HOWTO/mini/Partition.html
“Primary” partitions are the original partitioning scheme for PC
hard disks. However, there can be only four of them. To get past
this limitation, “extended” or “logical” partitions were invented.
By setting one of your primary partitions as an extended partition,
you can subdivide all the space allocated to that partition into
logical partitions. The number of logical partitions you can create
is much less limited than the number of primary partitions you can
create; however, you can have only one extended partition per drive.
Linux limits the number of partitions per drive to 15 partitions for
SCSI drives (3 usable primary partitions, 12 logical partitions),
and 63 partitions for IDE drives (3 usable primary partitions, 60
logical partitions).
The last issue you need to know about a PC BIOS is that your boot
partition—that is, the partition containing your kernel image—needs
to be contained within the first 1,024 cylinders of the drive.
Because the root partition is usually your boot partition, you need
to make sure your root partition fits into the first 1,024
cylinders.
If you have a large disk, you may have to use cylinder translation
techniques, which you can set in your BIOS, such as LBA translation
mode. (More information about large disks can be found in the Large
Disk mini-HOWTO[7].) If you are using a cylinder translation scheme,
your boot partition must fit within the _translated_ representation
of cylinder 1,024.
[7]
http://metalab.unc.edu/LDP/HOWTO/mini/Large-Disk.html
2.3.4 Device Names in Linux
Linux disks and partition names may be different from those in other
operating systems. You should know the names that Linux uses when
you create and mount partitions. The basic scheme can be found in
Table 2.1 on page [*].
Table 2.1: Linux Device Names
+------------------------------------------------------------------------------+
| Device | Linux Name |
|-----------------------------------------------+------------------------------|
| First floppy drive | /dev/fd0 |
|-----------------------------------------------+------------------------------|
| Second floppy drive | /dev/fd1 |
|-----------------------------------------------+------------------------------|
| First partition on /dev/hda (typically C: in | /dev/hda1 |
| other OSs) | |
|-----------------------------------------------+------------------------------|
| Fifth partition on /dev/hdc | /dev/hdc5 |
|-----------------------------------------------+------------------------------|
| Second partition on /dev/sdb | /dev/sdb2 |
|-----------------------------------------------+------------------------------|
| Entire Primary-Master IDE hard disk or CD-ROM | /dev/hda |
|-----------------------------------------------+------------------------------|
| Entire Primary-Slave IDE hard disk or CD-ROM | /dev/hdb |
|-----------------------------------------------+------------------------------|
| Entire Secondary-Master IDE hard disk or | /dev/hdc |
| CD-ROM | |
|-----------------------------------------------+------------------------------|
| Entire Secondary-Slave IDE hard disk or | /dev/hdd |
| CD-ROM | |
|-----------------------------------------------+------------------------------|
| First SCSI disk | /dev/sda |
|-----------------------------------------------+------------------------------|
| Second and remaining SCSI disks | /dev/sdb and so forth |
|-----------------------------------------------+------------------------------|
| First serial port (COM1 in other OSs) | /dev/ttyS0 |
|-----------------------------------------------+------------------------------|
| Second, third, etc. serial ports | /dev/ttyS1, /dev/ttyS2, etc. |
|-----------------------------------------------+------------------------------|
| SCSI tape units (automatic rewind) | /dev/st0, /dev/st1, etc. |
|-----------------------------------------------+------------------------------|
| SCSI tape units (no automatic rewind) | /dev/nst0, /dev/nst1, etc. |
|-----------------------------------------------+------------------------------|
| SCSI CD-ROMs | /dev/scd0, /dev/scd1, etc. |
+------------------------------------------------------------------------------+
The partitions on each disk are represented by appending a number to
the disk name. For example, the names hda1 and hda2 represent the
first and second partitions of the first IDE disk drive in your
system. Linux represents the primary partitions with the drive name
plus the numbers 1 through 4. For example, the first primary
partition on the first IDE drive is /dev/hda1. The logical
partitions are numbered starting at 5, so the first logical
partition on that same drive is /dev/hda5. Remember that the
extended partition—that is, the primary partition holding the
logical partitions—is not usable by itself. This applies to SCSI
drives as well as IDE drives.
Let’s assume you have a system with two SCSI disks, one at SCSI
address 2 and the other at SCSI address 4. The first disk (at
address 2) is then named sda and the second sdb. If the sda drive
has three partitions on it, these will be named sda1, sda2, and
sda3. The same applies to the sdb disk and its partitions. Note that
if you have two SCSI host bus adapters (i.e., controllers), the
order of the drives can get confusing. The best solution in this
case is to watch the boot messages, assuming you know the drive
models.
2.3.5 Recommended Partitioning Scheme
As described above, you should have a separate smaller root
partition and a larger /usr partition if you have the space. For
most users, the two partitions initially mentioned are sufficient.
This is especially appropriate when you have a single small disk,
because creating lots of partitions can waste space.
In some cases, you might need a separate /usr/local partition if you
plan to install many programs that are not part of the Debian
distribution. If your machine will be a mail server, you may need to
make /var/spool/mail a separate partition. Putting /tmp on its own
20 to 32MB partition, for instance, is a good idea. If you are
setting up a server with lots of user accounts, it’s generally good
to have a separate, large /home partition to store user home
directories. In general, the partitioning situation varies from
computer to computer depending on its uses.
For very complex systems, you should see the Multi Disk HOWTO[8]. It
contains in-depth information, mostly of interest to people setting
up servers.
[8]
http://metalab.unc.edu/LDP/HOWTO/Multi-Disk-HOWTO.html
Swap partition sizes should also be considered. There are many views
about swap partition sizes. One rule of thumb that works well is to
use as much swap as you have system memory, although there probably
isn’t much point in going over 64MB of swap for most users. It also
shouldn’t be smaller than 16MB, in most cases. Of course, there are
exceptions to these rules. If you are trying to solve 10,000
simultaneous equations on a machine with 256MB of memory, you may
need a gigabyte (or more) of swap space.
As an example, consider a machine that has 32MB of RAM and a 1.7GB
IDE drive on /dev/hda. There is a 500MB partition for another
operating system on /dev/hda1. A 32MB swap partition is used on
/dev/hda3 and the rest, about 1.2GB, on /dev/hda2 is the Linux
partition.
2.3.6 Partitioning Prior to Installation
There are two different times that you can partition: prior to or
during the installation of Debian. If your computer will be solely
dedicated to Debian you should partition during installation as
described in section 3.5 on page [*]. If you have a machine with
more than one operating system on it, you should generally let the
other operating system create its own partitions.
The following sections contain information regarding partitioning in
your native operating system prior to Debian installation. Note that
you’ll have to map between how the other operating system names
partitions and how Linux names partitions; see Table 2.1 on page
[*].
Partitioning from DOS or Windows
If you are manipulating existing FAT or NTFS partitions, it is
recommended that you use either the scheme below or native Windows
or DOS tools. Otherwise, it is not really necessary to partition
from DOS or Windows; the Linux partitioning tools will generally do
a better job.
Lossless Repartitioning
One of the most common installations is onto a system that already
contains DOS (including Windows 3.1), Win32 (such as Windows 95, 98,
NT), or OS/2 and it is desired to put Debian onto the same disk
without destroying the previous system. As explained in section
2.3.1 on page [*], decreasing the size of an existing partition will
almost certainly damage the data on that partition unless certain
precautions are taken. The method described here, while not
guaranteed to protect your data, works extremely well in practice.
As a precaution, you should _make a backup_.
Before going any further, you should have decided how you will
divide up the disk. The method in this section will only split a
partition into two pieces. One will contain the original operating
system, and the other will be used for Debian. During the
installation of Debian, you will be given the opportunity to use the
Debian portion of the disk as you see fit, i.e., as swap or as a
filesystem.
The idea is to move all the data on the partition to the beginning
before changing the partition information, so that nothing will be
lost. It is important that you do as little as possible between the
data movement and repartitioning to minimize the chance of a file
being written near the end of the partition as this will decrease
the amount of space you can take from the partition.
The first thing you need is a copy of FIPS, which is available in
the tools directory on your Debian CD-ROM. This disk must be
bootable. Under DOS, a bootable floppy can be created using the
command sys a: for a previously formatted floppy or format a: /s for
an unformatted floppy. Unzip the archive and copy the files
RESTORRB.EXE, FIPS.EXE and ERRORS.TXT to the bootable floppy. FIPS
comes with very good documentation that you may want to read. You
should definitely read the documentation if you use a disk
compression driver or a disk manager. Create the disk and read the
documentation _before_ you continue.
The next thing to be done is to move all the data to the beginning
of the partition. DEFRAG, which comes standard with DOS 6.0 and
later, can easily do the job. See the FIPS documentation for a list
of other software that may also work. Note that if you have Windows
95 or higher, you must run DEFRAG from there, because DOS doesn’t
understand VFAT, which is used to support long filenames in Windows
95 and higher.
After running the defragmenter (which can take a while on a large
disk), reboot with the FIPS floppy disk you created. Simply type a:\
fips and follow the directions.
Note that there are many other other partition managers out there,
in case FIPS doesn’t work for you.
2.3.7 Debian Installation Steps
As you initially install Debian, you will proceed through several
different steps:
1. Boot the installation system
2. Initial system configuration
3. Install the base system
4. Boot the newly installed base system
5. Install the rest of the system
Booting the Debian installation system, the first step, is generally
done with the Rescue Floppy or from the CD-ROM.
Once you’ve booted into Linux, the dbootstrap program will launch
and guide you through the second step, the initial system
configuration. This step is described in detail in section 3 on page
[*].
The “Debian base system” is a core set of packages that are required
to run Debian in a minimal, stand-alone fashion. dbootstrap will
install it from your CD-ROM, as described in section 3.12 on page
[*]. Once you have configured and installed the base system, your
machine can “stand on its own.”
The final step is the installation of the remainder of the Debian
system. This would include the applications and documents that you
actually use on your computer, such as the X Window system, editors,
shells, and development environments. The rest of the Debian system
can be installed from CD-ROM. At this point, you’ll be using the
standard Debian package management tools, such as dselect. This step
is described in section 3.20 on page [*].
2.4 Choosing Your Installation Media
First, choose the boot media for the installation system. Next,
choose the method you will use to install the base system.
To boot the installation system, you have the following choices:
bootable CD-ROM, floppies, or a non-Linux boot loader.
CD-ROM booting is one of the easiest ways to install. Not all
machines can boot directly from the CD-ROM so you may still need to
use floppies. Booting from floppies is supported for most platforms.
Floppy booting is described in section 2.4.2 on page [*].
2.4.1 Installing from a CD-ROM
If your system supports booting from a CD-ROM, you don’t need any
floppies. Put the CD-ROM into the drive, turn your computer off, and
then turn it back on. You should see a Welcome screen with a boot
prompt at the bottom. Now you can skip down to section 2.5.
If your computer didn’t “see” the Debian CD-ROM, the easiest option
is to make two floppies for booting (described in section 2.4.2) and
then use them to start Debian. Don’t worry; after Debian is finished
with those two floppies, it will find your CD-ROM with no trouble.
2.4.2 Booting from Floppies
It’s not hard at all to boot from floppies. In fact, your CD-ROM
contains all the information necessary to create boot disks for you.
For these instructions, you will need to get two disks. Label the
first one “Debian 2.1 Install/Rescue Disk” and the second “Debian
2.1 Modules/Drivers Disk.”
Creating Floppies from Disk Images
Disk images are files containing the complete contents of a floppy
disk in _raw_ form. Disk images, such as resc1440.bin, cannot simply
be copied to floppy drives. A special program is used to write the
image files to floppy disk in _raw_ mode.
First, you need to get to a DOS prompt. In Windows 95 and above, you
can do this by double-clicking on an MS-DOS icon or by going to
Start\( \rightarrow \)Programs\( \rightarrow \)MS-DOS prompt. Then,
insert your Debian GNU/Linux CD-ROM into your CD-ROM drive. First,
you change to your CD-ROM drive. In most cases, this is D:.
C:\WINDOWS>D:
Now, change to the directory containing the disk images.
D:\>CD
\DISTS\SLINK\MAIN\DISKS-I386\2.1.8-1999-02-22
If you get an error, double-check what you’re typing. If the error
persists, manually issue CD \DISTS\SLINK\MAIN\DISKS-I386, then run
DIR, and then CD into the directory indicated. Note that the above
commands, and some other examples below, may appear as a single line
on your display even if they are wrapped here.
Now, you’re ready to create the first of two disks. Start the
program to write them out, rawrite2:
D:\DISTS\SLINK\MAIN\DISKS-I386\
2.1.8-1999-02-22>rawrite2
RaWrite 2.0 - Write disk file to
raw floppy diskette
Rawrite2 starts and displays its welcome message. Next, it asks for
the filename and diskette drive. You tell it to write resc1440.bin
to a:
Enter disk image source file name: resc1440.bin
Enter target diskette drive: a:
Rawrite2 now asks you to insert a disk into the floppy drive. Do so
and press Enter.
Plese insert a formatted diskette into
drive A: and press -ENTER- :
At this point, rawrite2 will create the first of the two disks. Now,
you need to repeat the process for the second disk:
D:\DISTS\SLINK\MAIN\DISKS-I386\
2.1.8-1999-02-22>rawrite2
RaWrite 2.0 - Write disk file to
raw floppy diskette
Enter disk image source file name: drv1440.bin
Enter target diskette drive: a:
Please insert a formatted diskette into
drive A: and press -ENTER- :
By now, your disks are created. You can now use the first one to
boot.
Booting Debian
You are now ready to boot into Debian! Shut down your existing
operating system, turn off your computer, and place the
Install/Rescue Disk into the floppy drive. Now turn your computer
back on. You should get a Welcome screen with a boot prompt at the
bottom.
2.5 Booting the Installation System
You should now have the boot prompt. Simply press Enter at this
point.
Once you press Enter, you should see the message Loading..., and
then Uncompressing Linux..., and then a screenful or so of
information about the hardware in your system. In general, you can
ignore these messages. Linux will look for various hardware devices
and will tell you what it finds and doesn’t find. Don’t worry about
messages at this point. Just wait until you see the Color Selection
screen. If you have trouble, see section B.2 on page [*].
3. Step-by-Step Installation
dbootstrap is the name of the program that is run after you have
booted into the installation system. It is responsible for initial
system configuration and the installation of the “base system.”
The main job of dbootstrap and the main purpose of your initial
system configuration is to configure certain core elements of your
system. For instance, this includes your IP address, host name, and
other aspects of your networking setup, if any. This also includes
the configuration of “kernel modules,” which are drivers that are
loaded into the kernel. These modules include storage hardware
drivers, network drivers, special language support, and support for
other peripherals. Configuring these fundamental things is done
first, because it is often necessary for the system to function
properly for the next steps of installation.
dbootstrap is a simple, character-based application. It is very easy
to use; generally, it will guide you through each step of the
installation process in a linear fashion. You can also go back and
repeat steps if you made a mistake. Navigation within dbootstrap is
accomplished with the arrow keys, Enter, and Tab.
3.1 Select Color or Monochrome Display
Once the system has finished booting, dbootstrap is invoked. The
first thing that dbootstrap asks about is your display. You should
see the “Select Color or Monochrome display” dialog box. If your
monitor is capable of displaying color, press Enter. The display
should change from black-and-white to color. Then press Enter again,
on the “Next” item, to continue with the installation.
If your monitor can display only black and white, use the arrow keys
to move the cursor to the “Next” menu item, and then press Enter to
continue with the installation.
3.2 Debian GNU/Linux Installation Main Menu
You may see a dialog box that says “The installation program is
determining the current state of your system and the next
installation step that should be performed.” This is a phase in
which the installation program automatically figures out what you
probably need to do next. In some cases, you may not even see this
box.
During the entire installation process, you will be presented with
the main menu, titled “Debian GNU/Linux Installation Main Menu.” The
choices at the top of the menu will change to indicate your progress
in installing the system. Phil Hughes wrote in the _Linux
Journal_[1] that you could teach a chicken to install Debian! He
meant that the installation process was mostly just _pecking_ at the
_Enter key_. The first choice on the installation menu is the next
action that you should perform according to what the system detects
you have already done. It should say “Next,” and at this point the
next step in installing the system will be taken.
[1]
http://www.linuxjournal.com
3.3 Configure the Keyboard
Make sure the highlight is on the “Next” item and press Enter to go
to the keyboard configuration menu.
Move the highlight to the keyboard selection you desire and press
Enter. Use the arrow keys to move the highlight. In most cases, you
can just use the default U.S. layout.
3.4 Last Chance to Back Up!
Did we tell you to back up your disks? Here’s your first chance to
wipe out all of the data on your disks and your last chance to save
your old system. If you haven’t backed up all of your disks, remove
the floppy from the drive, reset the system, and run backups.
3.5 Partition a Hard Disk
Whatever the “Next” menu selection is, you can use the down-arrow
key to select “Partition a Hard Disk.” Go ahead and do this now,
then press Enter.
The “Partition a Hard Disk” menu item presents you with a list of
disk drives you can partition and runs a partitioning application
called cfdisk. You must create at least one “Linux native” (type 83)
disk partition, and you probably want at least one “Linux swap”
(type 82) partition, as explained in later in this section.
You will now create the partitions that you need to install Debian.
For this example, the assumption is that you are partitioning an
empty hard disk.
The boot partition must reside within the first 1,024 of cylinders
of your hard disk (see section 2.3.3 on page [*]). Keeping that in
mind, use the right-arrow key to highlight the “New” menu selection,
and then press Enter. You will be presented with the choice of
creating a _primary_ partition or a _logical_ partition. To help
ensure that the partition containing the boot information is within
the first 1,024 cylinders, create a primary partition first. This
primary partition will be your “Linux native” partition.
Highlight the “Primary” menu selection and press Enter. Next you
will need to enter how large you want that partition to be. Review
section 2.3.2 on page [*] if you’re not sure how large it should be.
Remember to leave enough space for your swap partition (see section
2.3.5 on page [*]). Enter the parition size you want and then press
Enter. Next you will be asked if you want to place the partition at
the beginning of free space or at the end. Place it at the beginning
to help ensure that it lies within the first 1,024 cylinders.
Highlight “Beginning” and press Enter. At this point you will be
brought back to the main screen. Notice that the partition you
created is listed. By default, a Linux native partition was created.
This partition must now be made bootable. Make sure that the
“Bootable” menu selection is highlighted and press Enter. The
partition should now have the word “Boot” listed under the “Flags”
column.
With the remaining space, create another primary partition. Using
the down-arrow key, highlight the _free space_ entry in the
partition list. Now highlight the “New” menu selection and proceed
just as you did when you created the first primary partition. Notice
that the partition is listed as a Linux native partition. Because
this partition will be your swap partition, it must be denoted as
such. Make sure the partition you just created (your swap partition)
is highlighted and then press the left-arrow key until the “Type”
menu selection is highlighted, then press Enter. You will be
presented with a list of supported partition types. The Linux swap
partition type should already be selected. If it is not, enter the
number from the list that corresponds to the Linux swap partition
(82), and then press Enter. Your swap partition should now be listed
as a Linux swap partition under the “FS Type” column in the main
screen.
[Illustration: Figure 3.1: cfdisk screenshot]
Your cfdisk screen should look something like the screenshot in
Figure 3.1 on page [*]. The numbers may not be the same, but the
Flags and FS Type column shoulds be similar.
Until now, nothing on your disk has been altered. If you are
satisfied that the partition scheme you created is what you want,
press the left-arrow key until “Write” is highlighted, and press
Enter. Your hard disk has now been partitioned. Quit the cfdisk
application by selecting the “Quit” menu selection. Once you have
left cfdisk, you should be back in Debian’s dbootstrap installation
application.
3.6 Initialize and Activate a Swap Partition
This will be the “Next” menu item once you have created one disk
partition. You have the choice of initializing and activating a new
swap partition, activating a previously-initialized one, or doing
without a swap partition.
A swap partition is strongly recommended, but you can do without one
if you insist and if your system has more than 4MB RAM. If you wish
to do this, select the “Do Without a Swap Partition” item from the
menu and move on to the next section.
It’s always permissible to reinitialize a swap partition, so select
“Initialize and Activate a Swap Partition” unless you are sure you
know what you are doing. This menu choice will first present you
with a dialog box reading “Please select the partition to activate
as a swap device.” The default device presented should be the swap
partition you’ve already set up; if so, just press Enter.
Next you have the option to scan the entire partition for unreadable
disk blocks caused by defects on the surface of the hard disk
platters. This is useful if you have MFM, RLL, or older SCSI disks,
and it never hurts (although it can be time-consuming). Properly
working disks in most modern systems don’t require this step,
because they have their own internal mechanisms for mapping out bad
disk blocks.
Finally, there is a confirmation message because initialization will
destroy any data previously on the partition. If all is well, select
“Yes.” The screen will flash as the initialization program runs.
3.7 Initialize a Linux Partition
At this point, the next menu item presented should be “Initialize a
Linux Partition.” If it isn’t, either you haven’t completed the disk
partitioning process, or you haven’t made one of the menu choices
dealing with your swap partition.
You can initialize a Linux partition, or alternately you can mount a
previously initialized one. Note that dbootstrap will _not_ upgrade
an old system without destroying it. If you’re upgrading, Debian can
usually upgrade itself, and you won’t need to use dbootstrap. The
Debian 2.1 release notes contain upgrade instructions[2].
[2]
http://www.debian.org/releases/slink/i386/release-notes/ch-upgrading-
req.en.html
If you are using old disk partitions that are not empty, i.e., if
you want to just throw away what is on them, you should initialize
them (which erases all files). Moreover, you must initialize any
partitions that you created in the disk partitioning step. About the
only reason to mount a partition without initializing it at this
point would be to mount a partition upon which you have already
performed some part of the installation process using this same set
of installation floppies.
Select the “Next” menu item to initialize and mount the / disk
partition. The first partition that you mount or initialize will be
the one mounted as / (pronounced “root”). You will be offered the
choice to scan the disk partition for bad blocks, as you were when
you initialized the swap partition. It never hurts to scan for bad
blocks, but it could take 10 minutes or more to do so if you have a
large disk.
Once you’ve mounted the / partition, the “Next” menu item will be
“Install Operating System Kernel and Modules” unless you’ve already
performed some of the installation steps. You can use the arrow keys
to select the menu items to initialize or to mount disk partitions
if you have any more partitions to set up. If you have created
separate partitions for /var, /usr, or other filesystems, you should
initialize or mount them now.
3.7.1 Mount a Previously-Initialized Partition
An alternative to the “Initialize a Partition” step is the “Mount a
Previously-Initialized Partition” step. Use this if you are resuming
an installation that was interrupted or if you want to mount
partitions that have already been initialized.
3.8 Install Operating System Kernel and Modules
This should be the next menu step after you’ve mounted your root
partition, unless you’ve already performed this step in a previous
run of dbootstrap. First, you will be asked to confirm that the
device you have mounted on root is the proper one. Next, you will be
offered a menu of devices from which you can install the kernel.
Choose the appropriate device from which to install the kernel and
modules; this will either be a CD-ROM device or the first floppy
device.
If you’re installing from floppies, you’ll need to feed in the
Rescue Floppy (which is probably already in the drive), followed by
the Drivers Floppy.
3.9 Configure PCMCIA Support
There is an alternate step, _before_ the “Configure Device Driver
Modules” menu selection, called “Configure PCMCIA Support.” This
menu is used to enable PCMCIA support.
If you do have PCMCIA but are not installing your Debian system
using it (i.e., installation with a PCMCIA Ethernet card), you need
not configure PCMCIA at this point. You can easily configure and
enable PCMCIA at a later point, after installation is complete.
However, if you are installing by way of a PCMCIA network device,
this alternate must be selected, and PCMCIA support must be
configured prior to configuring the network.
If you need to install PCMCIA, select the alternate below “Configure
Device Driver Modules.” You will be asked which PCMCIA controller
your system contains. In most cases, this will be i82365. In some
cases, it will be tcic; your laptop’s vendor-supplied specifications
should provide the information. You can generally leave the next few
sets of options blank. Again, certain hardware has special needs;
the Linux PCMCIA HOWTO[3] contains plenty of information in case the
default doesn’t work.
[3]
http://metalab.unc.edu/LDP/HOWTO/PCMCIA-HOWTO.html
In some unusual cases, you may also need to modify the file
/etc/pcmcia/config.opts. You can open your second virtual terminal
(Left Alt-F2) and edit the file there and then reconfigure your
PCMCIA, or you can manually force a reload of the modules using
insmod and rmmod.
Once PCMCIA is properly configured and installed, you should
configure your device drivers as described in the next section.
3.10 Configure Device Driver Modules
Select the “Configure Device Driver Modules” menu item and look for
devices that are on your system. Configure those device drivers, and
they will be loaded whenever your system boots.
You don’t have to configure all your devices at this point; what is
crucial is that any device configuration required for the
installation of the base system is done here.
At any point after the system is installed, you can reconfigure your
modules with the modconf program.
3.11 Configure the Network
You’ll have to configure the network even if you don’t have a
network, but you’ll only have to answer the first two
questions—“Choose the Host name,” and “Is your system connected to a
network?”
If you are connected to a network, you’ll need the information you
collected from 2.2.1. However, if your primary connection to the
network will be PPP, you should choose _NOT_ to configure the
network.
dbootstrap will ask you a number of questions about your network;
fill in the answers from 2.2.1. The system will also summarize your
network information and ask you for confirmation. Next, you need to
specify the network device that your primary network connection
uses. Usually, this will be eth0 (the first Ethernet device). On a
laptop, it’s more likely that your primary network device is pcmcia.
Here are some technical details you may find handy: The program
assumes the network IP address is the bitwise AND of your system’s
IP address and your netmask. It will guess the broadcast address is
the bitwise OR of your system’s IP address with the bitwise negation
of the netmask. It will guess that your gateway system is also your
DNS server. If you can’t find any of these answers, use the system’s
guesses. You can change them once the system has been installed, if
necessary, by editing
/etc/init.d/network. (On a Debian system, daemons are started by
/scripts
in the directory /etc/init.d/.)
3.12 Install the Base System
During the “Install the Base System” step, you’ll be offered a menu
of devices from which you may install the base system. Here, you
need to select your CD-ROM device.
You will be prompted to specify the path to the base2_1.tgz file. If
you have official Debian media, the default value should be correct.
Otherwise, enter the path where the base system can be found,
relative to the media’s mount point. As with the “Install Operating
System Kernel and Modules” step, you can either let dbootstrap find
the file itself or type in the path at the prompt.
3.12.1 Configure the Base System
At this point you’ve read in all of the files that make up a minimal
Debian system, but you must perform some configuration before the
system will run.
You’ll be asked to select your time zone. There are many ways to
specify your time zone; we suggest you go to the “Directories:” pane
and select your country (or continent). That will change the
available time zones, so go ahead and select your geographic
locality (i.e., country, province, state, or city) in the
“Timezones:” pane.
Next, you’ll be asked if your system clock is to be set to GMT or
local time. Select GMT (i.e., “Yes”) if you will only be running
Linux on your computer; select local time (i.e., “No”) if you will
be running another operating system as well as Debian. Unix (and
Linux is no exception) generally keeps GMT time on the system clock
and converts visible time to the local time zone. This allows the
system to keep track of daylight savings time and leap years, and
even allows a user who is logged in from another time zone to
individually set the time zone used on his or her terminal.
3.12.2 Make Linux Bootable Directly from the Hard Disk
If you elect to make the hard disk boot directly to Linux, you will
be asked to install a master boot record. If you aren’t using a boot
manager (and this is probably the case if you don’t know what a boot
manager is) and you don’t have another different operating system on
the same machine, answer “Yes” to this question. Note that if you
answer “Yes,” you won’t be able to boot into DOS normally on your
machine, for instance. Be careful. If you answer “Yes,” the next
question will be whether you want to boot Linux automatically from
the hard disk when you turn on your system. This sets Linux to be
the _bootable partition_—the one that will be loaded from the hard
disk.
Note that multiple operating system booting on a single machine is
still something of a black art. This book does not even attempt to
document the various boot managers, which vary by architecture and
even by sub-architecture. You should see your boot manager’s
documentation for more information. Remember: When working with the
boot manager, you can never be too careful.
The standard i386 boot loader is called “LILO.” It is a complex
program that offers lots of functionality, including DOS, NT, and
OS/2 boot management. To find out more about this functionality, you
can read the documentation in /usr/doc/lilo after your system is set
up.
3.13 Make a Boot Floppy
You should make a boot floppy even if you intend to boot the system
from the hard disk. The reason is that it’s possible for the hard
disk bootstrap to be mis-installed, but a boot floppy will almost
always work. Select “Make a Boot Floppy” from the menu and feed the
system a blank floppy as directed. Make sure the floppy isn’t
write-protected, because the software will format and write it. Mark
this the “Custom Boot” floppy and write-protect it once it has been
written.
3.14 The Moment of Truth
You system’s first boot on its own power is what electrical
engineers call the “smoke test.” If you have any floppies in your
floppy drive, remove them. Select the “Reboot the System” menu item.
If are booting directly into Debian and the system doesn’t start up,
either use your original installation boot media (for instance, the
Rescue Floppy) or insert the Custom Boot floppy if you created one,
and then reset your system. If you are _not_ using the Custom Boot
floppy, you will probably need to add some boot arguments. If
booting with the Rescue Floppy or similar technique, you need to
specify rescue root=rootfs, where rootfs is your root partition,
such as /dev/sda1.
Debian should boot, and you should see the same messages as when you
first booted the installation system, followed by some new messages.
3.15 Set the Root Password
The _root_ account is also called the _superuser;_ it is a login
that bypasses all security protection on your system. The root
account should be used only to perform system administration and for
as short a time as possible.
Any password you create should contain from six to eight characters,
and it should contain both uppercase and lowercase characters, as
well as punctuation characters. Take extra care when setting your
root password, since it is such a powerful account. Avoid dictionary
words or use of any personal information that could be guessed.
If anyone ever tells you he needs your root password, be extremely
wary. You should normally never give out your root account, unless
you are administering a machine with more than one system
administrator.
3.16 Create an Ordinary User
The system will ask you to create an ordinary user account. This
account should be your main personal login. You should _not_ use the
root account for daily use or as your personal login.
Why not? It’s a lot harder to do damage to the system as an ordinary
user than as root; system files are protected. Another reason is
that you might be tricked into running a _Trojan horse_ program—that
is, a program that takes advantage of your superuser powers to
compromise the security of your system behind your back. Any good
book on Unix system administration will cover this topic in more
detail. Consider reading one if this topic is new to you.
Name the user account anything you like. If your name is John Smith,
you might use “smith,” “john,” “jsmith,” or “js.”
3.17 Shadow Password Support
Next, the system will ask whether you want to enable shadow
passwords. This is an authentication system that makes your Linux
system a bit more secure. Therefore, we recommend that you enable
shadow passwords. Reconfiguration of the shadow password system can
also be done later with the shadowconfig program.
3.18 Remove PCMCIA
If you have no use for PCMCIA, you can choose to remove it at this
point. This will make your startup cleaner; also, it will make it
easier to replace your kernel (PCMCIA requires a lot of correlation
between the version of the PCMCIA drivers, the kernel modules, and
the kernel itself). In general, you will not need PCMCIA unless
you’re using a laptop.
3.19 Select and Install Profiles
The system will now ask you if you want to use the pre-rolled
software configurations offered by Debian. You can always choose
package-by-package what you want to install on your new machine.
This is the purpose of the dselect program, described below. But
this can be a long task with the thousands of packages available in
Debian!
So, you have the ability to choose _tasks_ or _profiles_ instead. A
_task_ is work you will do with the machine, such as “Perl
programming” or “HTML authoring” or “Chinese word processing.” You
can choose several tasks. A _profile_ is a category your machine
will be a member of, such as “Network server” or “Personal
workstation.” Unlike with tasks, you can choose only one profile.
To summarize, if you are in a hurry, choose one profile. If you have
more time, choose the Custom profile and select a set of tasks. If
you have plenty of time and want very precise control on what is or
is not installed, skip this step and use the full power of dselect.
Soon, you will enter into dselect. If you selected tasks or
profiles, remember to skip the “Select” step of dselect, because the
selections have already been made.
A word of warning about the size of the tasks as they are displayed:
The size shown for each task is the sum of the sizes of its
packages. If you choose two tasks that share some packages, the
actual disk requirement will be less than the sum of the sizes for
the two tasks.
Once you’ve added both logins (root and personal), you’ll be dropped
into the dselect program. dselect allows you to select _packages_ to
be installed on your system. If you have a CD-ROM or hard disk
containing the additional Debian packages that you want to install
on your system, or if you are connected to the Internet, this will
be useful to you right away. Otherwise, you may want to quit dselect
and start it later after you have transported the Debian package
files to your system. You must be the superuser (root) when you run
dselect. Information on how to use dselect is given in section 3.20.
3.20 Package Installation with dselect
It is now time to install the software packages of your choice on
your Debian system. This is done using Debian’s package management
tool, dselect.
3.20.1 Introduction
This section documents dselect for first-time users. It makes no
attempt to explain everything, so when you first meet dselect, work
through the help screens.
dselect is used to select which packages you wish to install (there
are currently about 2,250 packages in Debian 2.1). It will be run
for you during the installation. It is a very powerful and somewhat
complex tool. As such, having some knowledge of it beforehand is
highly recommended. Careless use of dselect can wreak havoc on your
system.
dselect will step you through the package installation process
outlined here:
1. Choose the access method to use.
2. Update list of available packages, if possible.
3. Select the packages you want on your system.
4. Install and upgrade wanted packages.
5. Configure any packages that are unconfigured.
6. Remove unwanted software.
As each step is completed successfully, dselect will lead you on to
the next. Go through them in order without skipping any steps.
Here and there in this document we talk of starting another shell.
Linux has six console sessions or shells available at any one time.
You switch between them by pressing Left Alt-F1 through Left Alt-F6,
after which you log in on your new shell and go ahead. The console
used by the install process is the first one, a.k.a. tty1, so press
Left Alt-F1 when you want to return to that process.
3.20.2 Once dselect Is Launched
Once in dselect, you will get this screen:
Debian Linux ‘dselect’ package handling frontend.
0. [A]ccess Choose the access method to use.
1. [U]pdate Update list of available packages, if possible.
2. [S]elect Request which packages you want on your system.
3. [I]nstall Install and upgrade wanted packages.
4. [C]onfig Configure any packages that are unconfigured.
5. [R]emove Remove unwanted software.
6. [Q]uit Quit dselect.
Let’s look at these one by one.
Access
[Illustration: Figure 3.2: dselect Access screen]
Here we tell dselect where our packages are. Ignore the order that
these appear in. It is very important that you select the proper
method for installation. You may have a few more methods listed, or
a few less, or you may see them listed in a different order; just
don’t worry about it. In the following list, we describe the
different methods.
multi_cd. Quite large and powerful, this complex method is the
recommended way of installing a recent version of Debian from a set
of multiple binary CDs. Each of these CDs should contain information
about the packages in itself and all prior CDs (in the file
Packages.cd). When you first select this method, be sure the CD-ROM
you will be using is not mounted. Place the last binary disk of the
set (we don’t need the source CDs) in the drive and answer the
questions you are asked:
CD-ROM drive location
Confirmation that you are using a multi-cd set
The location of the Debian distribution on the disk(s)
[ Possibly ] the location(s) of the Packages file(s)
Once you have updated the available list and selected the packages
to be installed, the multi_cd method diverges from normal procedure.
You will need to run an “install” step for each of the CDs you have,
in turn. Unfortunately, due to the limitations of dselect, it will
not be able to prompt you for a new disk at each stage; the way to
work for each disk is outlined here:
1. Insert the CD in your CD-ROM drive.
2. From the main dselect menu, select “Install.”
3. Wait until dpkg finishes installing from this CD. (It may report
installation successful, or possibly installation errors. Don’t
worry about these until later.)
4. Press Return to go back to the main dselect menu.
5. Repeat with the next CD in the set.
It may be necessary to run the installation step more than once to
cover the order of package installation; some packages installed
early may need to have later packages installed before they will
configure properly.
Running a “Configure” step is recommended to help fix any packages
that may end up in this state.
multi_nfs, multi_mount. These are similar to the multi_cd method and
are refinements on the theme of coping with changing media—for
example, installing from a multi_cd set exported via NFS from
another machine’s CD-ROM drive. indexdselect!multi-NFS, multi-mount
installation
apt. One of the best options for installation from a local mirror of
the Debian archive or from the network. This method uses the “apt”
system to do complete dependency analysis and ordering, so it’s most
likely to install packages in the optimal order.
Configuration of this method is straightforward. You may select any
number of different locations, mixing and matching file: URLs (local
disks or NFS mounted disks), http: URLs, or ftp: URLs. Note,
however, that the HTTP and FTP options do not support local
authenticating proxies.
If you have proxy server for either HTTP or FTP (or both), make sure
you set the http_proxy and ftp_proxy environment variables,
respectively. Set them from your shell before starting dselect by
using the following command:
# export http_proxy=
http://gateway:3128/
#
# dselect
#
#
#
#
Update
dselect will read the Packages or Packages.gz files from the mirror
and create a database on your system of all available packages. This
may take a while as it downloads and processes the files.
Select
Hang on to your hat. This is where it all happens. The object of the
exercise is to select just which packages you wish to have
installed.
Press Enter. If you have a slow machine, be aware that the screen
will clear and can remain blank for 15 seconds. So don’t start
bashing keys at this point.
The first thing that comes up on the screen is page 1 of the Help
file. You can get to this help by pressing ? at any point in the
“Select” screens, and you can page through the help screens by
hitting the . (full stop) key.
Before you dive in, note these points:
◼ To exit the “Select” screen after all selections are complete,
press Enter. This will return you to the main screen if there is
no problem with your selection. Otherwise, you will be asked to
deal with that problem. When you are happy with any given screen,
press Enter to get out.
◼ Problems are quite normal and are to be expected. If you select
package A and that package requires package B to run, dselect will
warn you of the problem and will most likely suggest a solution.
If package A conflicts with package B (i.e., if they are mutually
exclusive), you will be asked to decide between them.
Let’s look at the top two lines of the Select screen. This header
reminds us of some of the special keys listed in Table 3.1.
Table 3.1: Special dselect keys
+------------------------------------------------------+
| Key | Description |
|------+-----------------------------------------------|
| + | Select a package for installation. |
|------+-----------------------------------------------|
| = | Place a package on hold |
|------+-----------------------------------------------|
| - | Remove a package. |
|------+-----------------------------------------------|
| _ | Remove a package and its configuration files. |
|------+-----------------------------------------------|
| i, I | Toggle/cycle information displays. |
|------+-----------------------------------------------|
| o, O | Cycle through the sort options. |
|------+-----------------------------------------------|
| v, V | A terse/verbose toggle. |
+------------------------------------------------------+
Table 3.2 lists the states that dselect uses to denote the status of
each package it is aware of.
Table 3.2: dselect Package States
+-----------------------------------------------+
| Flag | Meaning | Possible values |
|------+-----------------+----------------------|
| E | Error | Space, R, I |
|------+-----------------+----------------------|
| I | Installed State | Space, *, -, U, C, I |
|------+-----------------+----------------------|
| O | Old Mark | *, -, =, _, n |
|------+-----------------+----------------------|
| M | Mark | *, -, =, _, n |
+-----------------------------------------------+
Rather than spell all this out here, I refer you to the Help screens
where all is revealed. One example, though.
You enter dselect and find a line like this:
EIOM Pri Section Package Description
** Opt misc loadlin a loader (running under DOS) for LINUX
This is saying that loadlin was selected when you last ran dselect
and that it is still selected, but it is not installed. Why not? The
answer must be that the loadlin package is not physically available.
It is missing from your mirror.
The information that dselect uses to get all the right packages
installed is buried in the packages themselves. Nothing in this
world is perfect, and it does sometimes happen that the dependencies
built into a package are incorrect, which means that dselect simply
cannot resolve the situation. A way out is provided where the user
can regain control; it takes the form of the commands Q and X, which
are available in the Select screen.
Q An override. Forces dselect to ignore the built-in dependencies
and to do what you have specified. The results, of course, will be
on your own head.
X Use X if you get totally lost. It puts things back the way they
were and exits.
Select screen (dselect) Keys that help you not to get lost (!) are
R, U, and D.
R Cancels all selections at this level. Does not affect selections
made at the previous level.
U If dselect has proposed changes and you have made further changes
U will restore dselect’s selections.
D Removes the selections made by dselect, leaving only yours.
An example follows. The boot-floppies package (not an example for
beginners, I know, but it was chosen because it has a lot of
dependencies) depends on these packages:
◼ libc6-pic
◼ slang1-pic
◼ sysutils
◼ makedev
◼ newt0.25
◼ newt0.25-dev
◼ popt
◼ zlib1g
◼ zlib1g-dev
◼ recode
The person maintaining boot-floppies also thinks that the following
packages should be installed. These are not, however, essential:
◼ lynx
◼ debiandoc-sgml
◼ unzip
When you select boot-floppies, dselect brings up the conflict
resolution screen. You’ll notice that all the required packages have
been selected.
Pressing the R key puts things back to the starting point.
EIOM Pri Section Package Description
__ Opt admin boot-floppie Scripts to create the Debian
__ Opt devel newt0.25-dev Developer’s toolkit for newt
__ Opt devel slang1-dev The S-Lang programming library
__ Opt devel slang1-pic The S-Lang programming library
If you decide now that you don’t want boot-floppies, just press
Enter.
Pressing the D key puts things the way I selected them in the first
place:
EIOM Pri Section Package Description
_* Opt admin boot-floppie Scripts to create the Debian
__ Opt devel newt0.25-dev Developer’s toolkit for newt
__ Opt devel slang1-dev The S-Lang programming library
__ Opt devel slang1-pic The S-Lang programming library
Pressing the U key restores dselect’s selections:
EIOM Pri Section Package Description
_* Opt admin boot-floppie Scripts to create the Debian
installation
_* Opt devel newt0.25-dev Developer’s toolkit for newt
_* Opt devel slang1-dev The S-Lang programming library
_* Opt devel slang1-pic The S-Lang programming library
I suggest running with the defaults for now; you will have ample
opportunities to add more later.
Whatever you decide, press Enter to accept and return to the main
screen. If this results in unresolved problems, you will be bounced
right back to another problem resolution screen.
The R, U, and D keys are very useful in “what if” situations. You
can experiment at will and then restore everything and start again.
_Don’t_ look on them as being in a glass box labeled “Break in Case
of Emergency.”
After making your selections in the Select screen, press I to give
you a big window, press t to take you to the beginning, and then use
the Page Down key to look quickly through the settings. This way you
can check the results of your work and spot glaring errors. Some
people have deselected whole groups of packages by mistake and not
noticed the error until too late. dselect is a _very_ powerful tool;
don’t misuse it.
You should now have the situation shown in Table 3.3.
Table 3.3: Expected Package Category States
+--------------------------------------+
| Package category | Status |
|------------------+-------------------|
| Required | all selected |
|------------------+-------------------|
| Important | all selected |
|------------------+-------------------|
| Standard | mostly selected |
|------------------+-------------------|
| Optional | mostly deselected |
|------------------+-------------------|
| Extra | mostly deselected |
+--------------------------------------+
Happy? Press Enter to exit the Select process. You can come back and
run Select again if you wish.
Install
dselect runs through the entire set of packages and installs those
selected. Expect to be asked to make decisions as you go. It is
often useful to switch to a different shell to compare, say, an old
configuration with a new one. If the old file is conf.modules, the
new one will be conf.modules.dpkg-dist.
The screen scrolls past fairly quickly on a fast machine. You can
stop and start it with Ctrl-s and Ctrl-q, respectively, and at the
end of the run, you will get a list of any uninstalled packages.
It can happen that a package does not get installed because it
depends on some other package that is listed for installation but is
not yet installed. The answer here is to run Install again. Cases
have been reported where it was necessary to run it four times
before everything slipped into place. This will vary by your
acquisition method.
Configure
Most packages get configured in step 3, but anything left hanging
can be configured here.
Remove
Removes packages that are installed but no longer required.
Quit
I suggest running /etc/cron.daily/find at this point, because you
have a lot of new files on your system. Then you can use locate to
get the location of any given file.
3.20.3 A Few Hints in Conclusion
When the install process runs dselect for you, you will doubtless be
eager to get Debian running as soon as possible. Well, please be
prepared to take an hour or so to learn your way around and then get
it right. When you enter the Select screen for the first time, don’t
make _any_ selections at all—just press Enter and see what
dependency problems there are. Try fixing them. If you find yourself
back at the main screen, run Select again.
You can get an idea of the size of a package by pressing i twice and
looking for the “Size” figure. This is the size of the compressed
package, so the uncompressed files will be a lot bigger (see
“Installed-Size,” which is in kilobytes, to know it).
Installing a new Debian system is a complex thing, but dselect can
do it for you as easy as can be. So take the time to learn how to
drive it. Read the help screens and experiment with i, I, o, and O.
Use the R key. It’s all there, but it’s up to you to use it
effectively.
3.21 Glossary
The following terms will be useful to you throughout this book and
in general when you’re talking about Debian.
Package. A file that contains everything needed to install,
de-install, and run a particular program. The program that handles
packages is dpkg. dselect is a front-end to dpkg. Experienced users
often use dpkg to install or remove a package.
Package names. All package names have the form xxxxxxxxxxx.deb.
Sample package names include the following:
◼ efax_08a-1.deb
◼ lrzsz_0.12b-1.deb
◼ mgetty_0.99.2-6.deb
◼ minicom_1.75-1.deb
◼ term_2.3.5-5.deb
◼ uucp_1.06.1-2.deb
◼ uutraf_1.1-1.deb
◼ xringd_1.10-2.deb
◼ xtel_3.1-2.deb
4. Logging In
Your system is now installed! Pat yourself on the back for a job
well done! Now it’s time to start using the system. In this chapter,
we introduce you to the Debian command line, some security
principles, and how to exit the system. In later chapters, we’ll go
into more detail on these topics and introduce you to the Debian
graphical interface, X11.
4.1 First Steps
After you quit dselect, you’ll be presented with the login: prompt.
You can now log in using the personal login and password you
selected; your system is now ready to use. Let’s examine what it
means to log in and how this process works.
To use Debian, you must identify yourself to the system. This is so
it knows who you are, what you have permission to do, and what your
preferences are.
To this end, you have a _username_ or _login_. If you installed
Debian yourself, you should have been asked to give such a name
during installation. If you are logging on to a system administered
by someone else, you’ll have to ask him for an account on the system
and a corresponding username.
You also have a password, so no one else can pretend to be you. If
you don’t have a password, anyone can log on to your computer from
the Internet and do bad things. If you’re worried about security,
you should have a password.
Many people prefer to trust others not to do anything malicious with
their account; hopefully your work environment doesn’t encourage
paranoia. This is a perfectly reasonable attitude; it depends on
your personal priorities and your environment. Obviously a home
system does not need to be as secure as a military installation.
Debian allows you to be as secure or as insecure as you like.
When you start Debian, you’ll see a _prompt:_ a request from the
computer for some information. In this case, the prompt is login:.
You should type your username and, when requested, your password.
The password does not appear on the screen as you type it. Press
Enter after both the username and the password. If you type your
username or password incorrectly, you’ll have to start over.
If you do it correctly, you’ll see a brief message and then a $
prompt. The $ is printed by a special program called the _shell_ and
is thus called a _shell prompt_. This is where you give commands to
the system.
Try entering the command whoami now. There is a _cursor_ to the
right of the shell prompt. Your cursor is a small underscore or
rectangle that indicates where you’re typing; it should move as you
type. Always press Enter when you’re done typing a shell command.
whoami tells your username. You’ll then get a new shell prompt.
For the rest of the book, when we say to enter a command, you should
type it at the shell prompt and press the Enter key.
When you’re done working, you may want to log out of the system. To
exit the shell, enter the exit command. Keep in mind that if you
remain logged in, someone could come along and use your account.
Hopefully you can trust those in your office or home not to do this;
but if you do not trust your environment, you should be certain to
log out when you leave.
4.2 Command History and Editing the Command Line
Whatever you type after the shell prompt and before pressing Enter
is called a _command line_. It’s a line of text that commands the
computer to do something. The Debian default shell offers several
features to make entering command lines easy.
You can scroll up to previous commands to run them again, or you can
modify them slightly and _then_ run them again. Try this: Enter any
command, such as whoami; then press the Up Arrow key. The whoami
command will reappear at the prompt. You can then press Enter to run
whoami a second time.
If you’ve entered several commands, you can keep pressing the Up
Arrow key to go back through them. This feature is handy if you’re
doing the same thing several times, or if you type a command
incorrectly and want to go back to fix it. You can press the Down
Arrow key to move in the other direction, toward your more recent
commands. If there are no more commands to move to, the computer
will beep.
You can also move around on the command line to make changes. The
easiest way is with the Left and Right Arrow keys. Try typing
whoasmi instead of whoami, and then use the Left Arrow key to move
back to the s. You can erase the s with the Backspace or Delete
keys.
There are more advanced features as well (no need to memorize them
all now, though). Try pressing Ctrl-a. This moves you to the
beginning of the line. Ctrl-k (the k stands for “kill”) deletes all
characters until the end of the line; try it from the middle of the
command line. Using Ctrl-a followed by Ctrl-k, you can delete the
entire command line. Ctrl-y pastes the last thing you killed,
reinserting it at the current cursor position (y stands for “yank,”
as in “yank it back”). Ctrl-e will move the cursor to the end of the
command line.
Go ahead and play around with command-line editing to get a feel for
it. Experiment.
4.3 Working as Root
Because Debian is a multiuser system, it’s designed to keep any one
user or program from breaking the entire system. The kernel will not
allow normal users to change important system files. This means that
things stay the way they’re supposed to, safe from accidents,
viruses, and even malicious pranks. Unlike other operating systems,
Debian is safe from these threats. You won’t need an anti-virus
program.
However, sometimes you need to change important system files; for
example, you might want to install new software or configure your
network connection. To do so, you have to have greater powers than a
normal user; you must become the _root user_ (also called the
_superuser_).
To become root, just log on with the username root and the root
password; this was set during installation, as described in section
3.15 on page [*].
At many sites, only the system administrator has the root password,
and only the system administrator can do the things that one must be
root to do. If you’re using your own personal computer, _you_ are
the system administrator, of course. If you don’t have root
privileges, you will have to rely on your system administrator to
perform any tasks that require root privileges.
Sometimes you’ll have the root password even on a shared corporate
or educational server, because the system administrator trusts you
to use it properly. In that case, you’ll be able to help administer
the system and customize it for your needs. But you should be sure
to use the password responsibly, respecting other users at all
times.
If you have the password, try logging on as root now. Enter the
whoami command to verify your identity. Then _log out immediately_.
When you’re root, the kernel will not protect you from yourself,
because root has permission to do anything at all to the system.
Don’t experiment while you’re root. In fact, don’t do anything as
root unless absolutely necessary. This isn’t a matter of security,
but rather of stability. Your system will run much better if it can
keep you from making mistakes.
You may find the su command more convenient than logging in as root.
su allows you to assume the identity of another user, usually root
unless you specify someone else. (You can remember that su stands
for Super User, though some say it stands for Set UserID.)
Here’s something to try. Log on as yourself—that is, not as root.
Then your session will look something like the one in Figure 4.1.
[Illustration: Figure 4.1: Sample session with su]
When you’re doing system administration tasks, you should do as much
as possible as yourself. Then use su, do the part that requires root
privileges, and use the exit command to turn off privileges so you
can no longer harm anything.
You can use su to assume the identity of any user on the system, not
just root. To do this, type su _user_ where _user_ is the user you
want to become. You’ll have to know the user’s password, of course,
unless you’re root at the time or the user has no password.
4.4 Virtual Consoles
The Linux kernel supports _virtual consoles_. These provide a way of
making your single screen and keyboard seem like multiple terminals
that are connected to the same system. Thankfully, using virtual
consoles is one of the simplest things about Debian: There are “hot
keys” for switching among the consoles quickly. To try it, log in to
your system and press Alt-F2 (simultaneously press the left Alt key,
and F2, that is, function key number 2).
You should find yourself at another login prompt. Don’t panic: You
are now on virtual console (VC) number 2! Log in here and do some
things—more whoami commands or whatever—to confirm that this is a
real login shell. Now you can return to virtual console number 1 by
pressing Alt-F1. Or you can move on to a _third_ virtual console, in
the obvious way (Alt-F3).
Debian comes with six virtual consoles enabled by default, which you
access with the Alt key and function keys F1 through F6.
(Technically, there are more virtual consoles enabled, but only six
of them allow you to log in. The others are used for the X Window
system or other special purposes.)
If you’re using the X Window system, it will generally start up on
the first unused virtual console—probably VC 7. Also, to switch from
the X virtual console to one of the first six, you’ll have to add
Ctrl to the key sequence. So that’s Ctrl-Alt-F1 to get to VC 1. But
you can go from a text VC to the X virtual console using only Alt.
If you never leave X, you won’t have to worry about this; X
automatically switches you to its virtual console when it starts up.
Once you get used to them, virtual consoles will probably become an
indispensable tool for getting many things done at once. (The X
Window system serves much the same purpose, providing multiple
windows rather than multiple consoles.) You can run a different
program on each VC or log on as root on one VC and as yourself on
another. Or everyone in the family can use his or her own VC; this
is especially handy if you use X, in which case you can run several
X sessions at once on different virtual consoles.
4.5 Shutting Down
_Do not just turn off the computer! You risk losing valuable data!_
If you are the only user of your computer, you might want to turn
the computer off when you’re done with it.
To avoid possibly weakening some hardware components, only turn off
the computer when you’re done for the day. Power up and power down
are the two greatest contributors to wear and tear on computer
components. Turning the computer on and off once a day is probably
the best compromise between your electric bill and your computer’s
lifespan.
It’s a bad thing to just press the power switch when you’re done
using the computer. It is also bad to reboot the machine (with the
Reset button) without first taking proper precautions. The Linux
kernel, in order to improve performance, has a disk cache. This
means it temporarily stores information meant for permanent storage
in RAM. Because memory is thousands of times faster than a disk,
this makes many file operations move more quickly. Periodically, the
information Linux has in memory is actually written to the disk.
This is called _syncing_. In order to turn off or reboot the
computer safely, you’ll have to tell the computer to clear
everything out of memory and put it in permanent storage.
To reboot, just type reboot or press Ctrl-Alt-Del (that’s Ctrl, Alt,
and Delete).
To shut down, you’ll have to log in as root. As root, just type the
command shutdown -h now. The sytem will go through the entire
shutdown procedure, including the sync command, which clears the
disk cache as described above. When you see System halted, it’s safe
to turn off the computer. If you have Advanced Power Management
(APM) support in your kernel and BIOS, the computer might shut
itself off and save you the trouble. APM is common in laptops and is
also found in certain desktop mainboards.
5. The Basics
It’s now time to explore the system in more detail. You’ve seen how
to log in and shut down the system. In this chapter, we explore the
Linux comand line, how Linux deals with files and directories, and
some basics on identifying yourself to others.
5.1 The Command Line and Man Pages
We’ve already discussed the command line—that is, commands you type
after the shell prompt. This section describes the structure of more
complicated command lines.
A minimal command line contains just a command name, such as whoami.
But other things are possible. For example, you might type: man
whoami. This command requests the online manual for the whoami
program (you may have to press the space bar to scroll through the
documentation or press q to quit). A more complicated example is man
-k PostScript. This command line has three parts. It begins with the
command name, man. Then it has an _option_ or _switch_, -k, followed
by an _argument_, PostScript. Some people refer to everything except
the command name as the _parameters_ of the command. So, options and
arguments are both parameters.
Options change the behavior of a command, switching on particular
features or functionality. They usually have a - before them. The
GNU utilities also have “long forms” for the options; the long form
of -k is -apropos. You can enter man -h or man -help to get a full
list of options for the man command. Every command will have its own
set of options, though most have -help and -version options. Some
commands, such as tar, do not require the “-” before their options
for historical reasons.
Anything that isn’t an option and isn’t the command name is an
_argument_ (in this case, PostScript). Arguments can serve many
purposes; most commonly, they are filenames that the command should
operate on. In this case, PostScript is the word you want man to
search for. In the case of man whoami, the argument was the command
you wanted information about.
Here’s a breakdown of the man -k PostScript command line:
man. The command name, tells the computer to look at the manual
pages. These provide documentation for commands. For example, man
whoami will give you documentation on the whoami command.
-k. The option, changes the behavior of man. Normally man expects a
command name, such as whoami, for an argument and looks for
documentation of that command. But with the -k or -apropos option,
it expects the argument to be a keyword. It then gives a list of all
manual pages with that keyword in their description.
PostScript. is the argument; because we used the -k option, it’s the
keyword to search for.
-k and PostScript are both parameters.
Go ahead and type man -k PostScript, and you will see a list of all
the manual pages on your system that have something to do with
PostScript. If you haven’t installed much software, you might see
the message PostScript: nothing appropriate instead.
5.1.1 Describing the Command Line
Note: You can skip this section if you want to move on.
There’s a traditional, concise way of describing command _syntax.
Syntax_ means the correct ways to combine various options and
arguments. For example, if you type man man to get the manual page
about man, you’ll see several syntax descriptions beginning with the
command name man. One of them will look like this: man -k [-M path]
keyword ...
Anything in brackets ([]) is an optional unit. In this case you
don’t have to use the -M option, but if you do, you must use a path
argument. You must use the -k option and the keyword argument. The
... means that you could have more of whatever came before it, so
you could look up several keywords.
Let’s look at one of the more complex descriptions from the man
manual page:
man [-c|-w|-tZT device] [-adhu7V]
[-m system[,...]] [-L locale] [-p string]
[-M path] [-P pager] [-r prompt] [-S list]
[-e extension] [[section] page ...] ...
There’s no need to go through all of this (and don’t worry about
what it all means), but do pay attention to the organization of the
description.
First, clusters of options usually mean you can use one or more of
them in different combinations, so -adhu7V means you can also use
-h. However, you can’t always use all combinations; this description
doesn’t make that clear. For example, -h is incompatible with other
options, but you could do man -du. Unfortunately, the description’s
format does not make this clear.
Second, the | symbol means “or.” So you can use the -c, the -w, _or_
the -tZT option, followed by a device argument.
Third, notice that you can nest the brackets, because they indicate
optional _units_. So if you have a section, you must also have a
page, because e page is not optional within the [[section] page]
unit.
There’s no need to memorize any of this, just refer to this section
as you read documentation.
5.2 Files and Directories
_Files_ are a facility for storing and organizing information,
analogous to paper documents. They’re organized into _directories_,
which are called _folders_ on some other systems. Let’s look at the
organization of files on a Debian system:
/.
A simple / represents the root directory. All other files
and directories are contained in the root directory. If you
are coming from the DOS/Windows world, / is very similar to
what C:is for DOS, that is the root of the filesystem. A
notable difference between DOS and Linux however, is that
DOS keeps several filesystems: C: (first hard disk), A:
(first floppy disk), and D: (either CD-ROM or second hard
disk), whereas Linux has all its files organized above the
same / root.
/home/janeq.
This is the home directory of user “janeq.” Reading left to
right, to get to this directory you start in the root
directory, enter directory home, and then enter directory
janeq.
/etc/X11/XF86Config.
This is the configuration file for the X Window system. It
resides in the X11 subdirectory of the /etc directory. /etc
is in turn a subdirectory of the root directory, /.
Things to note:
◼ Filenames are case-sensitive. That is, MYFILE and MyFile are
_different_ files.
◼ The root directory is referred to as simply /. Don’t confuse
this “root” with the root user, the user on your system with
“super powers.”
◼ Every directory has a name, which can contain any letters or
symbols _except_ /. The root directory is an exception; its name
is / (pronounced “slash” or “the root directory”), and it cannot
be renamed.
◼ While you can use almost any letters or symbols in a filename,
in practice it’s a bad idea. It is better to avoid characters that
often have special meanings on the command line, including: { } (
) [ ] ’ ‘ " \/ > < | ; ! # & ^ * %
◼ Also avoid putting spaces in filenames. If you want to separate
words in a name, good choices are the period, hyphen, and
underscore. You could also capitalize each word, LikeThis.
◼ Each file or directory is designated by a _fully-qualified
filename, absolute filename_, or _path_, giving the sequence of
directories which must be passed through to reach it. The three
terms are synonymous. All absolute filenames begin with the /
directory, and there’s a / before each directory or file in the
filename. The first / is the name of a directory, but the others
are simply separators to distinguish the parts of the filename.
◼ The words used here can be confusing. Take the following
example:
/usr/share/keytables/us.map.gz. This is a fully-qualified
/filename;
some people call it a _path_. However, people will also refer to
us.map.gz alone as a filename.
◼ There is also another use for the word “path.” The intended
meaning is usually clear from the context.
◼ Directories are arranged in a tree structure. All absolute
filenames start with the root directory. The root directory has a
number of branches, such as /etc and /usr. These subdirectories in
turn branch into still more subdirectories, such as /etc/init.d
and /usr/local. The whole thing together is called the “directory
tree.”
◼ You can think of an absolute filename as a route from the base
of the tree (/) to the end of some branch (a file). You’ll also
hear people talk about the directory tree as if it were a _family_
tree: Thus subdirectories have “parent,” and a path shows the
complete ancestry of a file.
◼ There are also relative paths that begin somewhere other than
the root directory. More on this later.
◼ No directory corresponds to a physical device, such as your hard
disk. This differs from DOS and Windows, in which all paths begin
with a device name such as C:\. The directory tree is meant to be
an abstraction of the physical hardware, so you can use the system
without knowing what the hardware is. All your files could be on
one disk—or you could have 20 disks, some of them connected to a
different computer elsewhere on the network. You can’t tell just
by looking at the directory tree, and nearly all commands work
just the same way no matter what physical device(s) your files are
really on.
Don’t worry if all this isn’t completely clear yet. There are many
examples to come.
5.2.1 Using Files: A Tutorial
To use your system, you’ll have to know how to create, move, rename,
and delete files and directories. This section describes how to do
so with the standard Debian commands.
The best way to learn is to try things. As long as you aren’t root
(and haven’t yet created any important personal files), you cannot
mess up too seriously. Jump in—type each of these commands at the
prompt and press Enter.
pwd
One directory is always considered the _current working directory_
for the shell you’re using. You can view this directory with the pwd
command, which stands for Print Working Directory. pwd prints the
name of the directory you’re working in—probably /home/yourname.
ls
ls stands for “list,” as in “list files.” When you type ls, the
system displays a list of all the files in your current working
directory. If you’ve just installed Debian, your home directory may
well be empty. If your working directory is empty, ls produces no
output, because there are no files to list.
cd /
cd means “change directory.” In this case, you’ve asked to change to
the root directory.
pwd
This verifies that you’re working in the root directory.
ls
Lets you see what’s in /.
cd
Typing cd with no arguments selects your home directory— /home/
yourname —as the current working directory. Try pwd to verify this.
Before continuing, you should know that there are actually two
different kinds of filenames. Some of them begin with /, the root
directory, such as
/etc/profile. These are called _absolute_ filenames because they
/refer
to the same file no matter what your current directory is. The other
kind of filename is _relative_.
Two directory names are used _only_ in relative filenames: . and ...
The directory . refers to the current directory, and .. is the
parent directory. These are “shortcut” directories. They exist in
_every_ directory. Even the root directory has a parent
directory—it’s its own parent!
So filenames that include . or .. are _relative_, because their
meaning depends on the current directory. If I’m in /usr/bin and
type ../etc, I’m referring to /usr/etc. If I’m in /var and type
../etc, I’m referring to /etc. Note that a filename without the root
directory at the front implicitly has ./ at the front. So you can
type local/bin, or ./local/bin and it means the same thing.
A final handy tip: The tilde ~ is equivalent to your home directory.
So typing cd ~ is the same as typing cd with no arguments. Also, you
can type things like cd ~/practice/mysubdirectory to change to the
directory
/home/yourname/practice/mysubdirectory. In a similar way, ~myuser is
equivalent to the home directory of the user “myuser,” which is
probably something like /home/myuser; so ~myuser/docs/debian.ps is
equivalent to
/home/myuser/doc/debian.ps.
/
/
/
Here are some more file commands to try out, now that you know about
relative filenames. cd to your home directory before you begin.
mkdir practice
In your home directory, make a directory called practice. You’ll use
this directory to try out some other commands. You might type ls to
verify that your new directory exists.
cd practice
Changes the directory to practice.
mkdir mysubdirectory
Creates a subdirectory of practice.
cp /etc/profile .
cp is short for “copy.” /etc/profile is just a random file on your
system, don’t worry about what it is for now. We’ve copied it to .
(recall that . just means “the directory I’m in now,” or the current
working directory). So this creates a copy of /etc/profile and puts
it in your practice directory. Try typing ls to verify that there’s
indeed a file called profile in your working directory, alongside
the new mysubdirectory.
more profile
This lets you view the contents of the file profile. more is used to
view the contents of text files. It’s called more because it shows
one screenful of the file at a time, and you press the space bar to
see more. more will exit when you get to the end of the file, or
when you press q (quit).
more /etc/profile
Verifies that the original looks just like the copy you made.
mv profile mysubdirectory
mv stands for “move.” You’ve moved the file profile from the current
directory into the subdirectory you created earlier.
ls
Verifies that profile is no longer in the current directory.
ls mysubdirectory
Verifies that profile has moved to mysubdirectory.
cd mysubdirectory
Changes to the subdirectory.
mv profile myprofile
Note that unlike some operating systems, there is no difference
between moving a file and renaming it. Thus there’s no separate
rename command. Note that the second argument to mv can be a
directory to move the file or directory into, or it can be a new
filename. cp works the same way.
As usual, you can type ls to see the result of mv.
mv myprofile ..
Just as . means “the directory I’m in now,” .. means “parent of the
current directory,” in this case the practice directory you created
earlier. Use ls to verify that that’s where myprofile is now.
cd ..
Changes directories to the parent directory—in this case practice,
where you just put myprofile.
rm myprofile
rm means “remove,” so this deletes myprofile. Be careful! Deleting a
file on a GNU/Linux system is _permanent_—there is no undelete. If
you rm it, it’s _gone, forever_. Be careful! To repeat, deleting a
file on a GNU/Linux system is _permanent_—there is no undelete. If
you rm it, it’s _gone, forever_.
rmdir mysubdirectory
rmdir is just like rm, only it’s for directories. Notice that rmdir
only works on empty directories. If the directory contains files,
you must delete those files first, or alternatively you can use rm
-r in place of rmdir.
cd ..
This moves out of the current directory, and into its parent
directory. Now you can type the following:
rmdir practice
This will delete the last remnants of your practice session.
So now you know how to create, copy, move, rename, and delete files
and directories. You also learned some shortcuts, like typing simply
cd to jump to your home directory, and how . and .. refer to the
current directory and its parent, respectively. You should also
remember the concept of the _root directory_, or /, and the alias ~
for your home directory.
5.2.2 Dot Files and ls -a
When you type ls, files beginning with a dot are not listed.
Traditionally, files that contain configuration information, user
preferences, and so on begin with a dot; these are hidden and out of
your way while you do your day-to-day work. Sample dot files are
~/.emacs, ~/.newsrc, ~/.bashrc, ~/.xsession, and ~/.fvwmrc. These
are used by Emacs, news readers, the Bash shell, the X Window
system, and the fvwm window manager, respectively. It is
conventional to end the dot filename with rc, but some programs
don’t. There are also directories beginning with a dot, such as
~/.gimp and ~/.netscape, which store preferences for the Gimp and
Netscape.
Sometimes a program will create a dot file automatically; for
example, Netscape allows you to edit your preferences with a
graphical dialog box and then it saves your choices. Other times you
will create them yourself using a text editor; this is the
traditional way to do it, but you have to learn the peculiar format
of each file—inconvenient at first, but it can give you a lot of
power.
To see dot files, you must use the -a option to ls. The long form of
-a is -all, if you find that easier to remember. You can also use -A
or -almost-all, which displays all dot files except . and ...
Remember that . is the current directory, and .. is the parent of
the current directory; because these are guaranteed to be in every
directory, there is no real reason to list them with ls. You already
know they are there.
5.3 Processes
We mentioned before that GNU/Linux is a _multitasking_ system. It
can do many tasks at once. Each of these tasks is called a
_process_. The best way to get a sense of this is to type top at the
shell prompt. You’ll get a list of processes, sorted according to
how much of the computer’s processing time they’re using. The order
will continuously change before your eyes. At the top of the
display, there’s some information about the system: how many users
are logged in, how many total processes there are, how much memory
you have and how much you’re using.
In the far left column, you’ll see the user owning each process. The
far right column shows which command invoked the process. You’ll
probably notice that top itself, invoked by you, is near the top of
the list (because anytime top checks on CPU usage, it will be active
and using CPU to do the check).
Note that in all the commands ending in “d” —such as kflushd and
inetd —the “d” stands for _daemon_.
Daemon originally meant Disks And Extensions MONitor. A daemon is a
non-interactive process, that is, it’s run by the system and users
never have to worry about it. Daemons provide services like Internet
connectivity, printing, or e-mail.
Now press u and give top your username when it asks. The u command
asks to see only those processes belonging to you; it allows you to
ignore all the daemons and whatever other people are doing. You
might notice bash, the name of your shell. You’ll pretty much always
be running bash.
Note that column two of the top display shows you the _PID_, or
Process IDentification number. Each process is assigned a unique
PID. You can use the PID to control individual processes (more on
that later). Another useful trick is to press ? to get a list of top
commands.
You may wonder about the difference between a “process” and a
“program.” In practice, people use the terms interchangeably.
Technically, the _program_ is the set of instructions written by a
programmer and kept on disk. The _process_ is the working
instantiation of the program kept in memory by Linux. But it’s not
that important to keep the terms straight.
Much of your interaction with a computer involves controlling
processes. You’ll want to start them, stop them, and see what
they’re up to. Your primary tool for this is the _shell_.
5.4 The Shell
The _shell_ is a program that allows you to interact with your
computer. It’s called a shell because it provides an environment for
you to work in—sort of a little electronic home for you as you
compute. (Think hermit crab.)
The simplest function of the shell is to launch other programs. You
type the name of the program you want to run, followed by the
arguments you want, and the shell asks the system to run the program
for you.
Of course, graphical windowing systems also fill this need.
Technically, Windows 95 provides a graphical shell, and the X Window
system is another kind of graphical shell. But “shell” is commonly
used to mean “command-line shell.”
Needless to say, the hackers who work on shells aren’t satisfied
with simply launching commands. Your shell has a bewildering number
of convenient and powerful features if you would like to take
advantage of them.
There are countless different shells available; most are based on
either the _Bourne shell_ or the _C shell_, two of the oldest
shells. The original Bourne shell’s program name is sh, while csh is
the C shell. Bourne shell variants include the Bourne Again Shell
from the GNU project (bash, the Debian default), the Korn shell
(ksh), and the Z shell (zsh). There is also ash, a traditional
implementation of the Bourne shell. The most common C shell variant
is tcsh (the t pays tribute to the TENEX and TOPS-20 operating
systems, which inspired some of tcsh’s improvements over csh).
bash is probably the best choice for new users. It is the default
and has all the features you’re likely to need. But all the shells
have loyal followings; if you want to experiment, install some
different shell packages and change your shell with the chsh
command. Just type chsh, supply a password when asked, and choose a
shell. When you next log in, you’ll be using the new shell.
5.5 Managing Processes with bash
Debian is a multitasking system, so you need a way to do more than
one thing at once. Graphical environments like X provide a natural
way to do this; they allow multiple windows on the screen at any one
time. Naturally, bash (or any other shell) provides similar
facilities.
Earlier you used top to look at the different processes on the
system. Your shell provides some convenient ways to keep track of
only those processes you’ve started from the command line. Each
command line starts a _job_ (also called a _process group_) to be
carried out by the shell. A job can consist of a single process or a
set of processes in a _pipeline_ (more on pipelines later).
Entering a command line will start a job. Try typing man cp, and the
cp manual page will appear on the screen. The shell will go into the
background and return when you finish reading the manual page (or
you can press q to quit rather than scrolling through the whole
thing).
But say you’re reading the manual page, and you want to do something
else for a minute. No problem. Press Ctrl-z while you’re reading to
_suspend_ the current foreground job and put the shell in the
foreground. When you suspend a job, bash will first give you some
information on it, followed by a shell prompt. You will see
something like this on the screen:
NAME cp - copy files SYNOPSIS cp [options] source
--More--
[1]+ Stopped man cp
$
Note the last two lines. The next to last is the job information,
and then you have a shell prompt.
bash assigns a _job number_ to each command line you run from the
shell. This allows you to refer to the process easily. In this case,
man cp is job number 1, displayed as [1]. The + means that this is
the last job you had in the foreground. bash also tells you the
current state of the job—Stopped—and the job’s command line.
There are many things you can do with jobs. With man cp still
suspended, try the following commands:
man ls
Starts a new job.
Ctrl-z
Suspends the man ls job; you should see its job information.
man mv
Starts yet another job.
Ctrl-z
Suspends it.
jobs
Asks bash for a display of current jobs. The result looks like this:
{$} jobs
[1] Stopped man cp
[2]- Stopped man ls
[3]+ Stopped man mv
{$}
Notice the - and +, denoting respectively the next to last and last
foreground jobs.
fg
Places the last foreground job (man mv, the one with the +) in the
foreground again. If you press the space bar, the man page will
continue scrolling.
Ctrl-z
Re-suspends man mv.
fg %1
You can refer to any job by placing a % in front of its number. If
you use fg without specifying a job, the last active one is assumed.
Ctrl-z
Re-suspends man cp.
kill %1
Kills off job 1. bash will report the job information, which will
look like this:
$ kill %1
[1]- Terminated man cp
$
bash is only asking the job to quit, and sometimes a job will not
want to do so. If the job doesn’t terminate, you can add the
-KILL[1] option to kill to stop asking and start demanding. For
example:
[1] Many people use the signal number -9 instead of the signal name
-KILL. However, it’s technically more portable to use the signal name.
$ kill -KILL %1
[1]- Killed man mv
$
The -KILL option forcibly and unconditionally kills off the job.
In technical terms, kill simply sends a signal. By default, it sends
a signal that requests termination (TERM, or signal 15) but you can
also specify a signal, and signal 9 (KILL) is the signal that forces
termination. The command name kill is not necessarily appropriate to
the signal sent; for example, sending the TSTP (terminal stop)
signal suspends the process but allows it to be continued later.
top
This brings the top display back up. Give the u command in top to
see only your processes. Look in the right-hand column for the man
ls and man mv commands. man cp won’t be there because you killed it.
top is showing you the system processes corresponding to your jobs;
notice that the PID on the left of the screen does not correspond to
the job number.
You may not be able to find your processes because they’re off the
bottom of the screen; if you’re using X (see Chapter 9 on page [*]),
you can resize the xterm to solve this problem.
Even these simple jobs actually consist of multiple processes,
including the man process and the pager more, which handles
scrolling one page at a time. You may notice the more processes are
also visible in top.
You can probably figure out how to clean up the remaining two jobs.
You can either kill them (with the kill command) or foreground each
one (with fg) and exit it. Remember that the jobs command gives you
a list of existing jobs and their status.
One final note: The documentation for bash is quite good, but it is
found in the Info help system rather than the man pages. To read it,
type info bash. See section A.1.1 for instructions on using the info
program. bash also contains a very good summary of its commands
accessible by the help command. help displays a list of available
topics; more information about each of them is accessible with the
command help topic name. Try typing help cd, for example. This will
give you details on the -P and -L arguments recognized by cd.
5.6 A Few bash Features
This section mentions just a few of the most commonly used Bash
features; for a more complete discussion see Chapter 6.
5.6.1 Tab Completion
The bash shell can guess what filename or command you are trying to
type and automatically finish typing it for you. Just type the
beginning of a command or filename and press Tab. If bash finds a
single unique completion, it will finish the word and put a space
after it. If it finds multiple possible completions, it will fill
out the part all completions have in common and beep. You can then
enter enough of the word to make it unique and press Tab again. If
it finds no completions, it will simply beep.
5.7 Managing Your Identity
Unix-like systems are multiuser, and so you have your own electronic
identity as a user on the system. Type finger _yourusername_ to look
at some of the information about you that’s publically available. To
change the name and shell listed there, you can use the commands
chfn and chsh. Only the superuser can change your login (username)
and directory. You’ll notice that it says “No plan.” A “plan” is
just some information you can make available to others. To create a
plan, you put whatever information you want people to see in a file
called .plan. To do this you’ll use a text editor; see section 8.2
on page [*]. Then finger yourself to see your plan. Others can
finger you to see your plan and to check whether you’ve received new
mail or read your mail.
Note that this finger information is available to the entire
Internet by default. If you don’t want this, read about configuring
inetd and the file
/etc/services. Eventually the installation manual will describe this
configuration, but for now you might try the man pages or just put
nonsense in for your finger information.
6. Using the Shell
As you have been reading this book, you’ve been interacting with the
shell already. The shell is the program that reads your commands and
then does what you ask it to. In this chapter, you explore the shell
in greater detail, with a special eye towards customizing the shell
to work as you want it to.
6.1 Environment Variables
Every process has an _environment_ associated with it. An
environment is a collection of _environment variables_. A variable
is a changeable value with a fixed name. For example, the name EMAIL
could refer to the value
[email protected]. The value can vary; EMAIL
could also refer to
[email protected].
Because your shell is a process like any other, it has an
environment. You can view your shell’s environment by entering the
printenv command. Figure 6.1 has some sample output from printenv.
On your system, the output will be different but similar.
[Illustration: Figure 6.1: Sample printenv output]
Environment variables are one way to configure the system. For
example, the EDITOR variable lets you select your preferred editor
for posting news, writing e-mail, and so on.
Setting environment variables is simple. For practice, try
customizing your shell’s prompt and your text file viewer with
environment variables. First, let’s get a bit of background
information.
man less
This command lets you view the online manual for the less command.
In order to show you the text one screenful at a time, man invokes a
pager that shows you a new page of text each time you press the
space bar. By default, it uses the pager called more.
Go ahead and glance over the man page for less, which is an enhanced
pager. Scroll to a new page by pressing space; press q to quit. more
will also quit automatically when you reach the end of the man page.
export PAGER=less
After reading about the advantages of less, you might want to use it
to read man pages. To do this, you set the environment variable
PAGER.
The command to set an environment variable within bash always has
this format:
Illustration: Figure 6.2: Changing the prompt
export NAME=value
export means to move the variable from the shell into the
environment. This means that programs other than the shell (for
instance, a file viewer) will be able to access it.
echo $PAGER
This is the easiest way to see the value of a variable. $PAGER tells
the shell to insert the value of the PAGER variable _before_
invoking the command. echo echoes back its argument: in this case,
it echoes the current PAGER value, less.
man more
Displays the more manual. This time, man should have invoked the
less pager.
less has lots of features that more lacks. For example, you can
scroll backward with the b key. You can also move up and down (even
sideways) with the arrow keys. less won’t exit when it reaches the
end of the man page; it will wait for you to press q.
You can try out some less-specific commands, like b, to verify that
they don’t work with more and that you are indeed using more.
unset PAGER
If you don’t want to specify a pager anymore, you can unset the
variable. man will then use more by default, just as it did before
you set the variable.
echo $PAGER
Because PAGER has been unset, echo won’t print anything.
PS1=hello:
Just for fun, change your shell prompt. $ should now change; see
Figure 6.2 for details.
export is not necessary, because you’re changing the shell’s own
behavior. There’s no reason to export the variable into the
environment for other programs to see. Technically, PS1 is a _shell
variable_ rather than an environment variable.
If you wanted to, you could export the shell variable, transforming
it into an environment variable. If you do this, programs you run
from the shell can see it.
6.2 Where Commands Reside: The PATH Variable
When you type a command into the shell, it has to find the program
on your hard disk before executing it. If the shell had to look all
over the disk, it would be very slow; instead, it looks in a list of
directories contained in the PATH environment variable. This list of
directories makes up the shell’s _search path;_ when you enter a
command, it goes through each one in turn looking for the program
you asked to run.
You may need to change the PATH variable if you install programs
yourself in a non-standard location. The value of PATH is a
colon-separated list of directories. The default value on Debian
systems is as follows:
/usr/local/bin:/usr/bin:/bin:/usr/bin/X11:/usr/games
/
/
/
/
This value is defined in the file /etc/profile and applies to all
users. You can easily change the value, just as you can change any
environment variable. If you type the command ls, the shell will
first look in
/usr/local/bin; ls isn’t there, so it will try /usr/bin; when that
/fails,
it will check /bin. There it will discover /bin/ls, stop its search,
and execute the program /bin/ls. If /usr/bin/X11/ls existed (it
doesn’t, but pretend), it would be ignored.
You can see which ls the shell is going to use with the type
command. type ls will give you the answer /bin/ls. Try it yourself.
Try asking where type itself resides:
$ type type
type is a shell builtin
type isn’t actually a program; it’s a function provided by the
shell. However, you use it just like an external program.
There are a number of commands like this; type man builtins to read
the man page describing them. In general, you don’t need to know
whether a command is a builtin or a real program; however, builtins
will not show up in the output of ps or top because they aren’t
separate processes. They’re just part of the shell.
6.3 Configuration Files
Many applications on Linux systems allow you to alter how they
behave at certain times by altering files containing configuration
information. These configuration files may contain application
start-up information, run-time settings and application shutdown
settings. In general, a configuration filename is based on the name
of the application for which it contains settings. Such a naming
convention allows you to more readily determine which configuration
file contains settings for a given application.
6.3.1 System-Wide Versus User-Specific Configuration
It’s important to remember that there are two different kinds of
configurations on a Debian system. _System-wide configuration_
affects all users. System-wide settings are made in the /etc
directory, so you generally must be root in order to change
system-wide settings. You might configure the way the system
connects to the Internet, for example, or have web browsers on the
system always start on the company home page. Since you want these
settings to apply to all users, you make the changes in /etc. Sample
configuration files in /etc include /etc/X11/XF86Config,
/etc/lynx.cfg, and /etc/ppp/options. In fact, nearly all the files
/in /etc
are configuration files.
_User configuration_ affects only a single user. Dotfiles are used
for user configuration. For example, the file ~/.newsrc stores a
list of which USENET (discussion group) articles you have read and
which groups you subscribe to. This allows news readers such as trn
or GNUS to display unread articles in the groups you’re interested
in. This information will be different for every user on the system,
so each user has his own .newsrc file in his home directory.
6.4 Aliases
If you use the same command often, you might get tired of typing it.
bash lets you write shorter _aliases_ for your commands.
Say you always use the -almost-all and -color=auto options to ls.
You quickly get tired of typing ls -almost-all -color=auto. So you
make an alias:
alias myls=’ls -almost-all -color=auto’
Now you can type myls instead of the full command. To see what myls
really is, run the command type myls. To see a list of aliases
you’ve defined, simply type alias on a line by itself.
[Illustration: Figure 6.3: Redirecting output]
6.5 Controlling Input and Output
Throughout your experiences with Linux, you will most likely find
that manipulating application input and output can be a very
powerful thing to do. This section describes some of the things that
controlling input and output can do for you.
6.5.1 stdin, stdout, Pipelines, and Redirection
Every process has at least three connections to the outside world.
The _standard input_ is one source of the process’s data; the
_standard output_ is one place the process sends data; and the
_standard error_ is a place the process can send error messages.
(These are often abbreviated stdin, stdout, and stderr.)
The words “source” and “place” are intentionally vague. These
standard input and output locations can be changed by the user; they
could be the screen, the keyboard, a file, even a network
connection. You can specify which locations to use.
When you run a program from the shell, usually standard input comes
from your keyboard, and standard output and error both go to your
screen. However, you can ask the shell to change these defaults.
For example, the echo command sends it output to standard output,
normally the screen. But you can send it to a file instead with the
_output redirection operator_, >. For example, to put the word
“Hello” in the file myfile, use this command:
echo Hello > myfile
Use cat or your text file pager (more or less) to view myfile’s
contents; see Figure 6.3.
You can change the standard input of a command with the _input
redirection operator_, <. For example, cat < myfile will display the
contents of myfile. This is not useful in practice; for convenience,
the cat command accepts a filename argument. So you can simply say
cat myfile, and the effect will be the same. redirection operators
Under the hood, cat < myfile means that the shell opens myfile and
then feeds its contents to the standard input of cat. cat myfile,
without the redirection operator, means that the cat command
receives one argument (myfile) opens the file itself, and then
displays the file.
There’s a reason for the double functionality, however. For example,
you can connect the standard output of one command to the standard
input of another. This is called a _pipeline_, and it uses the _pipe
operator_[1], |.
[1] Depending on your keyboard, this may either appear as a vertical
bar or a broken vertical bar, but it can almost always be found above
the backslash (\).
Perhaps you want to see the GNU General Public License in reverse.
To do this, you use the tac command (it’s cat, only backward). Try
it out:
tac /usr/doc/copyright/GPL
Unfortunately, it goes by too quickly to read. So you only get to
see a couple of paragraphs. The solution is a pipeline:
tac /usr/doc/copyright/GPL | less
This takes the standard output of tac, which is the GPL in reverse,
and sends it to the standard input of less.
You can chain as many commands together as you like. Say you have an
inexplicable desire to replace every G with Q. For this you use the
command tr G Q, like this:
tac /usr/doc/copyright/GPL | tr G Q | less
You could get the same effect using temporary files and redirection,
for example:
tac /usr/doc/copyright/GPL > tmpfile
tr G Q < tmpfile > tmpfile2
less < tmpfile2
rm tmpfile tmpfile2
Clearly a pipeline is more convenient.
6.6 Filename Expansion
Often you want a command to work with a group of files. _Wildcards_
are used to create a _filename expansion pattern:_ a series of
characters and wildcards that expands to a list of filenames. For
example, the pattern
/etc/* expands to a list of all[2]
the files in /etc.
[2] Actually, files beginning with . are not included in the expansion
of *.
* is a wildcard that can stand for any series of characters, so the
pattern /etc/* will expand to a list of all the filenames beginning
with
/etc/.
/
/
/
This filename list is most useful as a set of arguments for a
command. For example, the /etc directory contains a series of
subdirectories called rc0.d, rc1.d, etc. Normally to view the
contents of these, you would type the following:
ls /etc/rc0.d /etc/rc1.d /etc/rc2.d /etc/rc3.d
ls /etc/rc4.d /etc/rc5.d /etc/rc6.d /etc/rcS.d
This is tedious. Instead, you can use the ? wildcard as shown here:
ls /etc/rc?.d
/etc/rc?.d expands to a list of filenames that begin with rc,
/followed by
any single character, followed by .d.
Available wildcards include the following:
* Matches any group of 0 or more characters.
? Matches exactly one character.
[...] If you enclose some characters in brackets, the result is a
wildcard that matches those characters. For example, [abc] matches
either a, or b, or c. If you add a ^ after the first bracket, the
sense is reversed; so [^abc] matches any character that is not a, b,
or c. You can include a range, such as [a-j], which matches anything
between a and j. The match is case sensitive, so to allow any
letter, you must use [a-zA-Z].
Expansion patterns are simple once you see some concrete examples:
*.txt This will give you a list of all filenames that end in .txt,
since the * matches anything at all.
*.[hc] This gives a list of filenames that end in either .h or .c.
a?? This gives you all three-letter filenames that begin with a.
[^a]?? This gives you all three-letter filenames that do not begin
with a.
a* This gives you every filename that starts with a, regardless of
how many letters it has.
7. More on Files
In section 5.2 on page [*], we covered moving and renaming files
with mv, copying them with cp, removing them with rm, removing
directories with rmdir, and creating directories with mkdir. This
chapter will cover some more aspects of working with files.
Permissions
GNU and Unix systems are set up to allow many people to use the same
computer, while keeping certain files private or keeping certain
people from modifying certain files. You can verify this for
yourself. Log in as yourself, i.e. _NOT_ as root.
whoami
This verifies that you are not root. Then enter the following
command:
rm /etc/resolv.conf
You should be told Permission denied. /etc/resolv.conf is an
essential system configuration file; you aren’t allowed to change or
remove it unless you’re root. This keeps you from accidentally
messing up the system, and if the computer is a public one (such as
at an office or school), it keeps users from messing up the system
on purpose.
Now type ls -l /etc/resolv.conf.
This will give you output that looks something like this:
-rw-r-r- 1 root root 119 Feb 23 1997 /etc/resolv.conf
The -l option to ls requests all that additional information. The
info on the right is easy: The size of the file is 119 bytes; the
date the file was last changed is February 23, 1997; and the file’s
name is
/etc/resolv.conf. On the left side of the screen, things are a
/little more
complicated.
First, the brief, technical explanation: The -rw-r-r- is the _mode_
of the file, the 1 is the number of hard links to this file (or the
number of files in a directory), and the two roots are the user and
group owning the file, respectively.
So that was cryptic. Let’s go through it slowly.
7.1.1 File Ownership
Every file has two owners: a user and a group. The above case is a
little confusing because there’s a group called root in addition to
the root user. Groups are just collections of users who are
collectively permitted access to some part of the system. A good
example is a games group. Just to be mean, you might create a group
called games on your computer and then set up your system so that
only people in a games group are allowed to play games.
Here’s a more practical example. Consider a case in which you’re
setting up a computer for a school. You might want certain files to
be accessible only to teachers, not students, so you put all the
teachers in a single group. Then you can tell the system that
certain files belong to members of the group teachers, and that no
one else can access those files.
Let’s explore groups on the system. First, you can use the groups
command at the shell prompt. This will show you a list of the groups
to which you belong. Here’s an example:
$ groups
system-wide configuration!permissions!file
ownershipusername dialout cdrom floppy audio
It’s likely that you’re a member of only one group, which is
identical to your username. However, root can add you to other
groups. The above example shows a person that is a member of five
groups.
less /etc/group
This file lists the groups that exist on your system. Notice the
root group (the only member of this group is the root user), and the
group that corresponds to your username. There are also groups like
dialout (users who are allowed to dial out on the modem) and floppy
(users who can use the floppy drive). However, your system is
probably not configured to make use of these groups. It’s likely
that only root can use the floppy or the modem right now. For
details about this file, try reading man group.
ls -l /home
This command shows you that every user’s directory is owned by that
user and that user’s personal group.
Tip: If you just installed Debian, you may be the only user. You
can use the adduser command to add more users to the system.
7.1.2 Mode
In addition to being owned by one user and one group, every file and
directory also has a mode, which determines who’s allowed to read,
write, and execute the file (and run it, if it’s a program). There
are a few other things also determined by the mode, but they’re
advanced topics so we’ll skip them for now.
The mode looks like this in the ls output: -rw-r-r-. For now, we’ll
consider nine of these parts: those that control _read, write_, and
_execute_ permissions for the _user_ owning the file, the _group_
owning the file, and _others_ (everyone on the system, sometimes
called _world_).
In the mode line, the first “element” gives the file type. The - in
this case means it’s a regular file. If it was d, we’d be looking at
a directory. There are also other possibilities too complex to go
into here; for details, see section 13.2.2 on page [*].
The remaining nine elements are used to display the file’s mode. The
basic 9 bits (read, write, and execute for user, group, and other)
are displayed as three blocks of rwx.
So if all permissions are turned on and this is a regular file, the
mode will look like this: -rwxrwxrwx. If it was a directory with all
permissions turned off for others and full permissions for user and
group, it would be drwxrwx--.
Table 7.1: Permissions in Linux
+------------------------------------------------------------------------------+
| Code | Name | Allows for Files | Allows for Directories |
|------+---------+--------------------------+----------------------------------|
| r | read | Examine contents of file | List contents of directory |
|------+---------+--------------------------+----------------------------------|
| w | write | Modify file | Add or remove files in directory |
|------+---------+--------------------------+----------------------------------|
| x | execute | Run as a command | Access files in directory |
+------------------------------------------------------------------------------+
Table 7.1 describes the meaning of the read, write, and execute
permissions for both files and directories.
Directory modes can be a little confusing, so here are some examples
of the effects of various combinations:
r-
The user, group, or other with these permissions may list the
contents of the directory, but can do nothing else. The files in the
directory can’t be read, changed, deleted, or manipulated in any
way. The only permitted action is reading the directory itself, that
is, seeing what files it contains.
rw-
Write permission has no effect in the absence of execute permission,
so this mode behaves just like the above mode.
r-x
This mode permits the files in a directory to be listed and permits
access to those files. However, files can’t be created or deleted.
Access means that you can view, change, or execute the files as
permitted by the files’ own permissions.
-x
Files in this directory can be accessed, but the contents of the
directory can’t be listed, so you have to know what filename you’re
looking for in advance (unless you’re exceptionally good at
guessing). Files can’t be created or deleted.
rwx
You can do anything you want with the files in this directory, as
long as it’s permitted by the permissions on the files themselves.
Directory write permission determines whether you can delete files
in a directory. A read-only file can be deleted if you have
permission to write to the directory containing it. You can’t delete
a file from a read-only directory even if you’re allowed to make
changes to the file.
This also means that if you own a directory you can always delete
files from it, even if those files belong to root.
Directory execute permission determines whether you have access to
files - and thus whether file permissions come into play. If you
have execute permissions to a directory, file permissions for that
directory become relevant. Otherwise, file permissions just don’t
matter; you can’t access the files anyway.
7.1.3 Permissions in Practice
This section goes through a short example session to demonstrate how
permissions are used. To change permissions, we’ll use the chmod
command.
cd; touch myfile
There are a couple of new tricks here. First, you can use ; to put
two commands on one line. You can type the above as:
$ cd
$ touch myfile
or as:
$ cd; touch myfile
Either way the same thing will end up happening.
Recall that cd by itself returns you to your home directory. touch
is normally used to change the modification time of the file to the
current time. But it has another interesting feature: If the file
doesn’t exist, touch creates the file. So you’re using it to create
a file to practice with. Use ls -l to confirm that the file has been
created and notice the permissions mode:
$ ls -l
-rw-r-r- 1 user user 0 Nov 18 22:04 myfile
Obviously the time and user/group names will be different when you
try it. The size of the file is 0, because touch creates an empty
file. -rw-r-r- is the default permissions mode on Debian.
chmod u+x myfile
This command means to add (+) execute (x) permissions for the user
(u) who owns the file. Use ls -l to see the effects.
chmod go-r myfile
Here you’ve subtracted (-) read permission (r) from the group (g)
owning the file and from everyone else (others, o). Again, use ls -l
to verify the effects.
chmod ugo=rx myfile
Here you’ve set (=) user, group, and other permissions to read and
execute. This sets permissions to _exactly_ what you’ve specified
and unsets any other permissions. So all rx should be set, and all w
should be unset. Now, no one can write to the file.
chmod a-x myfile
a is a shortcut for ugo, or “all.” So all the x permissions should
now be unset.
rm myfile
With this command, you’re removing the file, but without write
permissions. rm will ask if you’re sure by displaying the following
message:
rm: remove ‘myfile’, overriding mode 0444?
You should respond by typing y and pressing Enter. This is a feature
of rm, not a fact of permissions. Permission to delete a file comes
from the directory permissions, and you have write permission in the
directory. However, rm tries to be helpful, figuring that if you
didn’t want to change the file (and thus remove write permission),
you don’t want to delete it either, so it asks you.
What was that 0444 business in the question from rm? The permissions
mode is a twelve-digit binary number, like this: 000100100100. 0444
is this binary number represented as an octal (base 8) number, which
is the conventional way to write a mode. So you can type chmod 444
myfile instead of chmod ugo=r myfile.
7.2 Files Present and Their Locations
Now that you can navigate the directory tree, let’s take a guided
tour of the files and directories you created when you installed
Debian. If you’re curious, cd to each directory and type ls to see
its contents. If the listing doesn’t fit on the screen, try ls |
less, where | is the “pipe” character, generally found on the same
key with backslash.
/ As already mentioned, this is the root directory, which contains
/ every
other directory.
/root
But don’t get /confused with /root! /root is the home
directory of the root user, or superuser. It’s a directory
called /root, but it isn’t _the_ root directory /.
/home This is where all normal users—that is, all users except
root—have their home directories. Each home directory is named after
the user who owns it, for example, /home/jane. If you’re using a
large system at a school or business, your system administrator may
create additional directories to contain home directories: /home1
and /home2 for example. On some other systems, you’ll see an
additional level of subdirectories: /home/students/username,
/home/staff/username, etc.
Your home directory is where you put all your personal work,
e-mail and other documents, and personal configuration
preferences. It’s your home on the system.
/bin
This directory contains “binaries,” executable files that
are essential to the operation of the system. Examples are
the shell (bash) and file commands such as cp.
/sbin
This directory contains “system binaries,” utilities that
the root user or system administrator might want to use, but
that you probably won’t want to use in your day-to-day
activities.
/usr
/usr contains most of the files you’ll be interested in. It
/has
many subdirectories. /usr/bin and /usr/sbin are pretty much
like
/bin and /sbin, except that the directories in /usr are not
considered “essential to the operation of the system.”
While not essential to getting the computer working, /usr
does contain the applications you’ll use to get real work
done. Also in
/usr, you’ll find the /usr/man, /usr/info, and /usr/doc
directories. These contain manual pages, info pages, and
other documentation, respectively. And don’t forget
/usr/games!
/usr/local
The Debian system doesn’t install anything in this
directory. You should use it if you want to install software
that you compile yourself or any software not contained in a
Debian package. You can also install software in your home
directory if you’ll be the only one using it.
/etc
/etc contains all the system-wide configuration files.
/Whenever
you want to change something that affects all users of your
computer—such as how you connect to the Internet or what
kind of video card you have—you’ll probably have to log on
as root and change a file in /etc.
/tmp
Here you’ll find temporary files, most of them created by
the system. This directory is generally erased on a regular
basis or every time you reboot the system. You can create
files here if you want, just be aware that they might get
deleted automatically.
/var
/var contains “variable” files that the system changes
automatically. For example, incoming mail is stored here.
The system keeps a log of its actions here. There are a
number of other automatically generated files here as well.
You’ll mostly be interested in the contents of /var/log,
where you can find error messages that can help you figure
out what you’re system’s up to if something goes wrong.
Clearly there are many more directories on the system—far too many
to describe every one.
For changing things, you’ll usually want to confine yourself to your
home directory and /etc. On a Debian system, there’s rarely an
occasion to change anything else, because everything else is
automatically installed for you.
/etc is used to configure the _system_ as a whole. You’ll use your
/own home
directory, a subdirectory of /home, for configuring your own
preferences and storing your personal data. The idea is that on a
day-to-day basis, you confine yourself to /home/_yourname_, so
there’s no way you can break anything. Occasionally you log in as
root to change something in a system-wide directory, but only when
it’s absolutely necessary. Of course, if you’re using Debian at a
school or business and someone else is the system administrator, you
won’t have root access and will be able to change only your home
directory and any other directory that you own. This limits what you
can do with the system.
7.3 File Compression with gzip
Often it would be nice to make a file smaller—say, to download it
faster, or so it takes up less space on your disk. The program to do
this is called gzip (GNU zip). Here’s how it works:
$ cd; cp /etc/profile ./mysamplefile
This switches to your home directory and copies an arbitrarily
chosen file (/etc/profile) to your current directory, in the process
renaming it mysamplefile. This gives you a file to play with when
using gzip.
$ ls -l
Lists the contents of the current directory. Note the size of
mysamplefile.
$ gzip mysamplefile
Compresses mysamplefile.
$ ls -l
Observe the results of this command: mysamplefile is now called
mysamplefile.gz . It’s also a good bit smaller.
$ gunzip mysamplefile.gz; ls -l
This uncompresses the file. Observe that mysamplefile has returned
to its original state. Notice that to uncompress, one uses gunzip,
not gzip.
$ rm mysamplefile
Use this command to remove the file, since it was just to practice
with.
7.4 Finding Files
There are two different facilities for finding files: find and
locate. find searches the actual files in their present state.
locate searches an index generated by the system every morning at
6:42 a.m. (this is a cron job, explained elsewhere in this book).
locate won’t find any files that were created after the index was
generated. However, because locate searches an index, it’s much
faster—like using the index of a book rather than looking through
the whole thing.
To compare the two ways of finding files, pretend you can’t remember
where the X configuration file XF86Config resides.
$ locate XF86Config
This should be pretty fast. You’ll get a list of filenames that
contain XF86Config, something like this:
/etc/X11/XF86Config
/
/usr/X11R6/lib/X11/XF86Config
/
/usr/X11R6/lib/X11/XF86Config.eg
/
/usr/X11R6/man/man5/XF86Config.5x.gz
/
/
/
/
Now try the find command:
$ find / -name XF86Config
You will hear a lot of disk activity, and this will take a lot
longer. Results will look something like this:
/etc/X11/XF86Config
/
/usr/X11R6/lib/X11/XF86Config
/
find: /var/spool/cron/atjobs: Permission denied
find: /var/spool/cron/atspool: Permission denied
find: /var/lib/xdm/authdir: Permission denied
Notice that find found only files that were named _exactly_
XF86Config, rather than any files containing that string of letters.
Also, find actually tried to look in every directory on the
system—including some where you didn’t have read permissions. That’s
why you got the Permission denied messages.
The syntax is different as well. With find, you had to specify what
directory to search in, whereas locate automatically chose the root
directory. And you had to specify a search by name using the -name
option. You could also have searched for files using many other
criteria, such as modification date or owner. To have find search
for files whose names match XF86Config, you’d have to use a
wildcard:
$ find / -name ’*XF86Config*’
Like most of the command line tools, find accepts wildcards as
arguments.
In general, find is a more powerful utility, and locate is faster
for everyday quick searches. The full range of possible searches
would take a long time to explain; for more details , type info
find, which will bring up the very thorough info pages on find and
locate.
7.5 Determining a File’s Contents
Debian comes with a utility that can guess at the contents of a file
for you. Although it is not 100% accurate, you can use the following
command to explore your system:
$ file /bin/cp
You should see something like this:
/bin/cp: ELF 32-bit LSB executable, Intel 386, version 1
/
/
/
/
Skipping the technical parts, this is an executable file for Intel
machines.
$ file /etc/init.d/boot
The preceding command gives this response:
/etc/init.d/boot: Bourne shell script text
/
/
/
/
meaning that this is a text file containing a Bourne shell script.
7.6 Using a File Manager
Instead of moving files around by hand, you can use a _file
manager_. If you move a lot of files around, a file manager can make
your work more efficient. There are text-based file managers, such
as GNU Midnight Commander (mc), and a number of file managers for
the X Window system (for example gmc for the X Window version of GNU
Midnight Commander).
Describing each of these is outside the scope of this book, but you
may want to try them out if the command line doesn’t meet your
needs.
8. Working with Text Files
Text files are prevelant on a GNU/Linux system. They hold everything
from documentation to configuration files. Fortunately, it’s easy to
work with them.
8.1 Viewing Text Files
A _text file_ is simply a normal file that happens to contain
human-readable text. There’s nothing special about it otherwise. The
other kind of file, a binary file, is meant to be interpreted by the
computer.
You can view either kind of file with the less file pager if you
have it installed (install it if you haven’t, it’s quite useful).
Type less
/etc/profile to view a sample text file. Notice that you can read
/the
characters even if their meaning is obscure. Type less /bin/ls to
view a binary file. As you can see, the ls program is not meant to
be read by humans.
Sometimes, you’ll find files that end with .gz. These files may be
viewed with zless; you can run it like so:
zless /usr/doc/ae/changelog.Debian.gz
Tip: zless is great for viewing documentation, which is often
shipped in .gz form.
The difference between the two kinds of files is purely a matter of
what they contain, unlike in some other systems (such as DOS and
MacOS), which actually treat the files differently.
Text files can contain shell scripts, documentation, copyright
notices, or any other human-readable text.
Incidentally, this illustrates the difference between _source code_
and _binary executables_. /bin/ls is a binary executable you can
download from Debian, but you can also download a text file that
tells the computer how to create /bin/ls. This text file is the
source code. Comparing /bin/ls to /etc/profile illustrates how
important source code is if someone wants to understand and modify a
piece of software. Free software provides you or your consultants
with this all-important source code.
8.2 Text Editors
A _text editor_ is a program used to create and change the contents
of text files. Most operating systems have a text editor: DOS has
edit, Windows has Notepad, MacOS has SimpleText.
Debian provides a large variety of text editors. vi and Emacs are
the classic two, which are probably both the most powerful and the
most widely used. Both vi and Emacs are quite complex and require
some practice, but they can make editing text extremely efficient.
Emacs runs both in a terminal and under the X Window system; vi
normally runs in a terminal but the vim variant has a -g option that
allows it to work with X. text editors
Simpler editors include nedit, ae, jed, and xcoral. nedit and xcoral
provide easy-to-use X Window system graphical interfaces. There are
also several vi variants. Additionally, you can find and a GNU Emacs
variant called XEmacs.
This book does not cover the use of any particular editor in detail,
though we will briefly introduce ae since it is small, fast, and can
be found even on the Debian rescue disks, so it pays to know a bit
about it for usage in a pinch. When you need to do more serious
editing, check out vim or GNU Emacs. Emacs provides an excellent
interactive tutorial of its own; to read it, load Emacs with the
emacs command and type F1 t. Emacs is an excellent choice for new
users interested in a general-purpose or programming editor.
8.3 Using ae
You can start ae by giving it the name of a file to edit, like so:
$ ae filename.txt
This will bring up an editor screen. The top part of this screen
provides some quick help; the bottom shows the file you’re editing.
Moving around in this editor is simple; just use the arrow keys. You
can save the file by pressing C-x C-s and then exit the editor by
pressing C-x C-c. Once you feel comfortable with the editor, you can
press C-x C-h to turn off the help. That’s it! Knowing this will let
you do basic editing. For programming or more detailed editing work,
you’ll want to investigate other editors as discussed earlier.
9. The X Window System
This chapter describes the X Window system graphical user interface.
It assumes that you have already successfully configured X as
described in the Installation Manual (again, the install manual is
not yet written; for now you will need to use the XFree86 HOWTO, the
contents of /usr/doc/X11, and this chapter). Once you install X, you
can enter the X environment by typing startx or via xdm, depending
on your choice during configuration.
9.1 Introduction to X
A GUI (Graphical User Interface) is part and parcel of the Windows
and Mac operating systems. It’s basically impossible to write an
application for those systems that does not use the GUI, and the
systems can’t be used effectively from the command line. GNU/Linux
is more _modular_, that is, it’s made up of many small, independent
components that can be used or not according to one’s needs and
preferences. One of these components is the X Window system, or
simply X.
This component is also sometimes called X11. Please note that “X
Windows” is _not_ correct.
X itself is a means for programs to talk to your mouse and video
card without knowing what kind of mouse and video card you have.
That is, it’s an _abstraction_ of the graphics hardware. User
applications talk to X in X’s language; X then translates into the
language of your particular hardware. This means that programs only
have to be written once, and they work on everyone’s computer.
In X jargon, the program that speaks to the hardware is known as an
_X server_. User applications that ask the X server to show windows
or graphics on the screen are called _X clients_. The X server
includes a _video driver_, so you must have an X server that matches
your video card.
The X server doesn’t provide any of the features one might expect
from a GUI, such as resizing and rearranging windows. A special X
client, called a _window manager_, draws borders and title bars for
windows, resizes and arranges windows, and provides facilities for
starting other X clients from a menu. Specific window managers may
have additional features.
Window managers available on a Debian system include fvwm, fvwm2,
icewm, afterstep, olvwm, wmaker, twm, and enlightenment. You’ll
probably want to try them all and pick your favorite.
Neither the X server nor the window manager provide a _file
manager;_ that is, there aren’t any windows containing icons for
your files and directories. You can launch a file manager as a
separate application, and there are many of them available. The
GNOME desktop project is developing an icon-based file manager and
other GUI facilities. See the GNOME homepage[1] for the latest news
on this.
[1]
http://www.gnome.org/
A final feature of X is its _network transparency_, meaning that X
clients don’t care if they’re talking to an X server on the same
machine or an X server somewhere on the network. In practical terms,
this means you can run a program on a more powerful remote machine
but display it on your desktop computer.
9.2 Starting the X Environment
There are two ways to start X. The first is to start X manually when
you feel like using it. To do so, log in to one of the text consoles
and type startx. This will start X and switch you to its virtual
console.
The second (and recommended) way to use X is with xdm or X Display
Manager. Basically, xdm gives you a nice graphical login prompt on
the X virtual console (probably VC 7), and you log in there.
By default, either method will also start an xterm, which is a small
window containing a shell prompt. At the shell prompt, you can type
any commands just as you would on a text VC. So you can follow all
the examples in this book using xterm; the only difference between
an xterm and the text console is that you don’t have to log on to
the xterm because you already logged on to X.
There are also a lot of things you can do only in X, which are
covered in this chapter.
One note: The default xterm window has a smallish font. If you have
a small monitor or very high resolution or bad eyesight, you may
want to fix this. Follow these steps:
1. Move the mouse pointer into the center of the xterm window.
2. Hold down the Control key and the _right_ mouse button
simultaneously. This will give you a font menu.
3. Point to the font you want and release the mouse button.
9.3 Basic X Operations
There are certain commonly used operations in X that you should
familiarize yourself with. This section describes some of the basic
operations that you may find useful.
9.3.1 The Mouse
The mouse in X works pretty much the same as the mouse on other
systems, except that it has three buttons. If your mouse has only
two, you can simulate the middle button by clicking both buttons
simultaneously. This is kind of tricky and annoying, so investing in
a $15 three-button mouse probably isn’t a bad idea. These are
available from most computer retailers.
The buttons are numbered from left to right assuming you have a
right-handed mouse. So button one is on the left, two is in the
middle, and three is on the right. You may see either the numbers or
the locations in documentation.
X has a simple built-in copy-and-paste facility. To select text to
copy, you click and drag with the left mouse button. This should
select the text to copy, assuming the application you’re using has
copy-and-paste support. To paste the text, you click the middle
mouse button in a different X application. For example, if you
receive an e-mail containing an URL, you can select the URL with the
left button and then click in your web browser’s “Location” field
with the middle button to paste it in.
9.3.2 X Clients
Programs that communicate with the X server are called X clients.
Most of these programs will ask the X server to display windows on
the screen.
You start an X client the same way you start any other Debian
program. Simply type the name of the client on the command line. Try
typing xterm into an existing xterm window, and a new xterm client
will appear on the screen.
You may notice that the original xterm is now useless, because your
shell is waiting for the second xterm to finish. To avoid this
problem, you can run the X client in the backgroundby adding a &
after the command name like this: xterm &. If you forget, you can
place a running process in the background. First suspend the process
with CTRL-z, and then place it in the background with the bg
command.
If you use a program often, your window manager will generally
provide a way to put that program on a convenient graphical menu.
9.3.3 Troubleshooting
Sometimes when you launch an X client from a graphical menu, you
won’t be able to see any error messages if it fails. You can find
any error messages in the file ~/.xsession-errors.
9.3.4 Leaving the X Environment
To leave X, you need to use a menu. Unfortunately for beginners,
this is different for every window manager, and for most window
managers, it can be configured in many ways. If there’s an obvious
menu, look for an entry like “Exit” or “Close Window Manager.” If
you don’t see a menu, try clicking each of the mouse buttons on the
background of the screen. If all else fails, you can forcibly kill
the X server by pressing CTRL-ALT-Backspace. Forcibly killing the
server destroys any unsaved data in open applications.
9.4 Customizing Your X Startup
When you start X, Debian runs some shell scripts that start your
window manager and other X clients. By default, a window manager, an
xconsole, and an xterm are started for you.
To customize your X startup, the file /etc/X11/config must contain
the line allow-user-xsession. If it does not, log in as root and add
the line now. Then log back in as yourself and continue the
tutorial.
You can see how Debian’s X startup works in the file /etc/X11/
Xsession. Note that you can change the behavior of /etc/X11/Xsession
by modifying the file /etc/X11/config, which specifies a few
system-wide preferences.
To run the clients of your choice when X starts, you create an
executable shell script called .xsession in your home directory.
$ touch ~/.xsession
This creates the file.
$ chmod u+x ~/.xsession
This makes the file executable.
Once .xsession is created, you need to edit it to do something
useful with your favorite text editor. You can do anything you want
to in this script. However, when the script’s process terminates, X
also terminates.
In practical terms, this means that you often end the script with a
call to exec. Whatever program you exec will replace the script
process with itself, so commands found after the exec line will be
ignored. The program you exec will become the new owner of the
script process, which means that X will terminate when this new
program’s process terminates.
Say you end your .xsession with the line exec fvwm. This means that
the fvwm window manager will be run when X starts. When you quit the
fvwm window manager, your X session will end, and all other clients
will be shut down. You do not have to use a window manager here; you
could exec xterm, in which case typing exit in that particular xterm
would cause the entire X session to end.
If you want to run other clients before you use exec, you will need
to run them in the background. Otherwise .xsession will pause until
each client exits and then continue to the next line. See the
previous section on running jobs in the background (basically you
want to put an ampersand at the end, as in xterm &).
You can take advantage of this behavior, though. If you want to run
commands at the end of your X session, you can have your .xsession
run a window manager or the like and wait for it to finish. That is,
leave off the exec and the &; just enter fvwm by itself. Then put
the commands of your choice after fvwm.
It would probably help to look at a few sample .xsession files. In
all the examples, replace fvwm with the window manager of your
choice.
The simplest .xsession just runs a window manager:
exec fvwm
This will run fvwm, and the X session will end when fvwm exits. If
you do it without the exec, everything will appear to behave the
same way, but behind the scenes .xsession will hang around waiting
for fvwm, and .xsession will exit after fvwm does. Using exec is
slightly better because fvwm replaces .xsession instead of leaving
it waiting. You can use the ps or top command to verify this.
A more useful .xsession runs a few clients before starting the
window manager. For example, you might want some xterms and an
xclock whenever you start X. No problem; just enter xterm & xterm &
xclock & exec fvwm. Two xterms and an xclock start up in the
background, and then the window manager is launched. When you quit
the window manager, you’ll also quit X.
You might try it without the backgrounding just to see what happens.
Enter this command: xterm xclock exec fvwm. xterm will start, and
wait for you to exit it. Then xclock will start; you’ll have to exit
xclock before fvwm will start. The commands are run in sequence,
since the script waits for each one to exit.
You can use sequential execution to your advantage. Perhaps you want
to keep track of when you stop working every day:
xterm &
xclock &
fvwm
date >> ~/logout-time
This will fork off an xterm and an xclock and then run fvwm and wait
for it to finish. When you exit fvwm, it will move on to the last
line, which appends the current date and time to the file
~/logout-time.
Finally, you can have a program other than the window manager
determine when X exits:
xclock &
fvwm &
exec xterm
This script will run xclock and fvwm in the background and then
replace itself with xterm. When you exit the xterm, your X session
will end.
The best way to learn how to use .xsession is to try some of these
things out. Again, be sure you use chmod to make it executable;
failure to do so is a common error.
10. Filesystems
A Debian system uses a filesystem to store and manage your data.
This chapter introduces you to the filesystem, describes how to add
and remove filesystems, and shows you how to back up your system.
10.1 Concepts
It’s probably a good idea to explain a little theory before
discussing the mechanics of using disks. In particular, you must
understand the concept of a _filesystem_. This can be a bit
confusing because it has several meanings.
_The_ filesystem refers to the whole directory tree, starting with
the root directory /, as described in earlier chapters.
A filesystem in general means any organization of files and
directories on a particular physical device. “Organization” means
the hierarchical directory structure and any other information about
files one might want to keep track of: their size, who has
permission to change them, etc. So you might have one filesystem on
your hard disk, and another one on each floppy disk.
“Filesystem” is also used to mean a _type_ of filesystem. For
example, MS-DOS and Windows 3.1 organize files in a particular way,
with particular rules: Filenames can have only eight characters, for
example, and no permission information is stored. Linux calls this
the msdos filesystem. Linux also has its own filesystem, called the
ext2 filesystem (version two of the ext filesystem). You’ll use the
ext2 filesystem most of the time unless you’re accessing files from
another operating system or have other special needs.
Any physical device you wish to use for storing files must have at
least one filesystem on it. This means a filesystem in the second
sense—a hierarchy of files and directories, along with information
about them. Of course, any filesystem has a type, so the third sense
will come into play as well. If you have more than one filesystem on
a single device, each filesystem can have a different type—for
example, you might have both a DOS partition and a Linux partition
on your hard disk.
10.2 mount and /etc/fstab
This section describes how to mount a floppy or Zip disk, discusses
the
/dev directory, and addresses distributing the directory tree over
multiple physical devices or partitions.
10.2.1 Mounting a Filesystem
On a GNU/Linux system there’s no necessary correspondence between
directories and physical devices as there is in Windows, in which
each drive has its own directory tree beginning with a letter (such
as C:\).
Instead, each physical device such as a hard disk or floppy disk has
one or more filesystems on it. In order to make a filesystem
accessible, it’s assigned to a particular directory in another
filesystem. To avoid circularity, the root filesystem (which
contains the root directory /) is not stored within any other
filesystem. You have access to it automatically when you boot
Debian.
A directory in one filesystem that contains another filesystem is
known as a _mount point_. A mount point is a directory in a first
filesystem on one device (such as your hard disk) that “contains” a
second filesystem, perhaps on another device (such as a floppy
disk). To access a filesystem, you must mount it at some mount
point.
So, for example, you might mount a CD at the mount point /cdrom.
This means that if you look in the directory /cdrom, you’ll see the
contents of the CD. The /cdrom directory itself is actually on your
hard disk. For all practical purposes, the contents of the CD become
a part of the root filesystem, and when you type commands and use
programs, it doesn’t make any difference what the actual physical
location of the files is. You could have created a directory on your
hard disk called /cdrom and put some files in it, and everything
would behave in exactly the same way. Once you mount a filesystem,
there’s no need to pay any attention to physical devices.
However, before you can mount a filesystem or actually create a
filesystem on a disk that doesn’t have one yet, it’s necessary to
refer to the devices themselves. All devices have names, which are
located in the /dev directory. If you type ls /dev now, you’ll see a
pretty lengthy list of every possible device you could have on your
Debian system. For a summary of some devices, see Table 2.1 on page
[*]. A more thorough list can be found on your system in the file
/usr/src/linux/Documentation/devices.txt.
To mount a filesystem, we want to tell Linux to associate whatever
filesystem it finds on a particular device with a particular mount
point. In the process, we might have to tell Linux what kind of
filesystem to look for.
10.2.2 Example: Mounting a CD-ROM
As a simple demonstration, we’ll go through mounting a CD-ROM, such
as the one you may have used to install Debian. You’ll need to be
root to do this, so be careful; whenever you’re root, you have the
power to manipulate the whole system, not just your own files. Also,
these commands assume there’s a CD in your drive; you should put one
in the drive now. Then start with the following command:
su
If you haven’t already, you need to either log in as root or gain
root privileges with the su (super user) command. If you use su,
enter the root password when prompted.
ls /cdrom
Use this command to see what’s in the /cdrom directory before you
start. If you don’t have a /cdrom directory, you may have to make
one using mkdir /cdrom.
mount
Simply typing mount with no arguments lists the currently mounted
filesystems.
mount -t iso9660 _CD-device_ /cdrom
For this command, you should substitute the name of your CD-ROM
device for _CD-device_ in the above command line. If you aren’t
sure, /dev/cdrom is a good guess because the install process should
have created this symbolic link on the system. If that fails, try
the different IDE devices:
/dev/hdc, etc. You should see a message like this: mount: block
/device dev/hdc is write-protected, mounting read-only.
/
/
/
The -t option specifies the type of the filesystem, in this case
iso9660. Most CDs are iso9660. The next argument is the name of the
device to mount, and the final argument is the mount point. There
are many other arguments for mount; see the manual page for details.
Once a CD is mounted, you may find that your drive tray will not
open. You must unmount the CD before removing it.
ls /cdrom
Confirms that /cdrom now contains whatever is on the CD in your
drive.
mount
Displays the list of filesystems again; notice that your CD drive is
now mounted.
umount /cdrom
This unmounts the CD. It’s now safe to remove the CD from the drive.
Notice that the command is umount with no “n,” even though it’s used
to unmount the filesystem.
exit
Don’t leave yourself logged on as root. Log out immediately, just to
be safe.
10.2.3 /etc/fstab: Automating the Mount Process
The file /etc/fstab (it stands for “filesystem table”) contains
descriptions of filesystems that you mount often. These filesystems
can then be mounted with a shorter command, such as mount /cdrom.
You can also configure filesystems to mount automatically when the
system boots. You’ll probably want to mount all of your hard disk
filesystems when you boot, so Debian automatically adds entries to
fstab to do this for you.
Look at this file now by typing more /etc/fstab. It will have two or
more entries that were configured automatically when you installed
the system. It probably looks something like this:
# /etc/fstab: static file system information.
# /
# / #
# / #
# <file system> <mount point> <type> <options> #<dump > <pass>
#
/dev/hda1 / ext2 defaults 0 1
/
/dev/hda3 none swap sw 0 0
/
proc /proc proc defaults 0 0
/dev/hda5 /tmp ext2 defaults 0 2
/
/dev/hda6 /home ext2 defaults 0 2
/
/dev/hda7 /usr ext2 defaults 0 2
/
/dev/hdc /cdrom iso9660 ro,noauto 0 0
/
/dev/fd0 /floppy auto noauto,sync 0 0
/
/
/
/
/
The first column lists the device the filesystem resides on. The
second lists the mount point, the third indicates the filesystem
type. The line beginning by proc is a special filesystem. Notice
that the swap partition (/dev/hda3 in the example) has no mount
point, so the mount point column contains none.
The last three columns may require some explanation.
The fifth column is used by the dump utility to decide when to back
up the filesystem. In most cases, you can put 0 here.
The sixth column is used by fsck to decide in what order to check
filesystems when you boot the system. The root filesystem should
have a 1 in this field, filesystems that don’t need to be checked
(such as the swap partition) should have a 0, and all other
filesystems should have a 2. It’s worth noting that the swap
partition isn’t exactly a filesystem in the sense that it does not
contain files and directories but is just used by the Linux kernel
as secondary memory. However, for historical reasons, the swap
partitions are still listed in the same file as the filesystems.
Column four contains one or more options to use when mounting the
filesystem. You can check the mount manpage for a summary; see
section 5.1 on page [*].
10.2.4 Removable Disks (Floppies, Zip Disks, Etc.)
Add the following lines to your /etc/fstab file:
/dev/sda1 /mnt/zip ext2 noauto,user 0 0
/
/dev/sda4 /mnt/dos msdos noauto,user 0 0
/
/
/
/
From now on, you’ll be able to mount the DOS-formatted Zip disks
with the command mount /mnt/dos, and you be able to mount
Linux-formatted Zip disks with the command mount /mnt/zip.
If you have SCSI hard disks in your system, you’ll have to change
sda to sdb or sdc in the example above.
10.3 Backup Tools
Backups are important under any operating system. Debian GNU/Linux
provides several different utilities that you might want to use.
Additionally, while many of these utilities were aimed at tape
backups originally, you’ll find that they are now being used for
other things. For instance, tar is being used for distributing
programs over the Internet. Some of the utilities that you’ll find
include the following:
◼ Taper is a menu-driven, easy-to-learn backup program that can
back up to a variety of media. Its limitation is that it doesn’t
handle large (4GB or larger) backups.
◼ dump is designed specifically for tapes; its main strengths are
its interface for file restores, low-level filesystem backups, and
incremental backup scheduling. Its limitations include the
inability to back up NFS or other non-ext2 filesystems and some
rather arcane defaults.
◼ GNU tar (short for Tape ARchiver) is an implementation of what
is probably the most widely used backup or archiving utility in
Linux today. It makes a good general purpose tool and can deal
with the widest variety of target media. Additionally, many
different systems can read tar files, making them highly portable.
tar’s weaknesses include a weaker incremental backup system than
dump and no interactive restore selection screen.
10.3.1 tar
Because tar is used so much, and for quite a bit in addition to
backups, it is being described here. For more details, see the tar
manual page; instructions for viewing manual pages can be found in
section 5.1 on page [*].
tar is an _archiver_. This means that tar can take many files and
combine them all into one large file or write them out to a backup
device such as a tape drive. Once you have this one large file, you
will often want to compress it; the -z option is great for this.
Hence, tar offers a great way to distribute programs and data on the
Internet, and you’ll find that it is used extensively for this
purpose.
Here’s a sample tar command line:
tar -zcvf myfiles.tar.gz /usr/local/bin
Let’s take a look at how this command can be broken down:
tar
Name of the command.—Tells tar that options will follow.
z
Tells tar to use gzip compression automatically; if you use this, it’s
good to add a .gz extension as well.
c
Tells tar to create a new archive.
v
This says to be verbose; that is, it tells tar to let you know what
it’s doing while it creates the archive.
f
This indicates that the next thing on the command line is the name of
the file to be created or the device to be used. If I used /dev/st0
here, for instance, it would write the backup to the tape drive.
myfiles.tar.gz This is the name of the file to be created.
/usr/local/bi
/
/
/
/
This is the name of the file or directory to store in the archive.
It’s also possible to specify several items here.
You may often find tar.gz files (or simply tgz files) on the
Internet. You can unpack these with a command like:
tar -zxvf filename.tar.gz
11. Networking
One of the key benefits of GNU/Linux over other systems lies in its
networking support. Few systems can rival the networking features
present in GNU/Linux. In this chapter, we tell you how to configure
your network devices.
11.1 PPP
This section is a quick-start guide to setting up PPP on Debian. If
it turns out that you need more details, see the excellent |PPP
HOWTO| from the Linux Documentation Project. The HOWTO goes into
much more detail if you’re interested or have unique needs.
11.1.1 Introduction
If you connect to the Internet over a phone line, you’ll want to use
PPP (Point-to-Point Protocol). This is the standard connection
method offered by ISPs (Internet service providers). In addition to
using PPP to dial your ISP, you can have your computer listen for
incoming connections - this lets you dial your computer from a
remote location.
11.1.2 Preparation
Configuring PPP on Debian GNU/Linux is straightforward once you have
all the information you’ll need. Debian makes things even easier
with its simple configuration tools.
Before you start, be sure you have all the information provided by
your ISP. This might include:
◼ Username or login
◼ Password
◼ Your static IP (Internet Protocol) address, if any (these look
like 209.81.8.242). This information isn’t needed for most ISPs.
◼ Bitmask (this will look something like 255.255.255.248). This
information isn’t needed for most ISPs.
◼ The IP addresses of your ISP’s name servers (or DNS).
◼ Any special login procedure required by the ISP.
Next, you’ll want to investigate your hardware setup: whether your
modem works with GNU/Linux and which serial port it’s connected to.
A simple rule determines whether your modem will work. If it’s a
“winmodem” or “host-based modem,” it won’t work. These modems are
cheap because they have very little functionality, and they require
the computer to make up for their shortcomings. Unfortunately, this
means they are complex to program, and manufacturers generally do
not make the specifications available for developers.
If you have a modem with its own on-board circuitry or an external
modem, you should have no trouble at all.
On GNU/Linux systems, the serial ports are referred to as
/dev/ttyS0,
/dev/ttyS1, and so on. Your modem is almost certainly connected to
/either
port 0 or port 1, equivalent to COM1: and COM2: under Windows. If
you don’t know which your modem is connected to, run the program
wvdialconf to try to detect it (see below); otherwise, just try both
and see which works.
If you want to talk to your modem or dial your ISP without using
PPP, you can use the minicom program. You may need to install the
minicom package to make the program available.
11.1.3 The Easy Way: wvdial
The simplest way to get PPP running is with the wvdial program. It
makes some reasonable guesses and tries to set things up for you. If
it works, you’re in luck. If it guesses wrong, you’ll have to do
things manually.
Be sure you have the following packages installed:
◼ ppp
◼ ppp-pam
◼ wvdial
When you install the wvdial package, you may be given the
opportunity to configure it. Otherwise, to set up wvdial, follow
these simple steps:
Log in as root, using su (as described in an earlier chapter).
touch /etc/wvdial.conf
touch will create the following file if the file doesn’t exist; the
configuration program requires an existing file.
wvdialconf /etc/wvdial.conf
This means you’re creating a configuration file, /etc/wvdial.conf.
Answer any questions that appear on the screen. wvdialconf will also
scan for your modem and tell you which serial port it’s on; you may
want to make a note of this for future reference.
11.2 Ethernet
Another popular way to connect to the Internet is via a LAN that
uses Ethernet. This gives you a high-speed local network in addition
to Internet access. Fortunately, though, you should have already
configured Ethernet networking during installation so there isn’t
much you need to do now. If you ever need to modify your
configuration, here are the files that you will be interested in:
◼ /etc/init.d/network has things such as your IP address, netmask,
and default route.
◼ /etc/hostname records your hostname.
◼ /etc/hosts also records your hostname and IP address.
12. Removing and Installing Software
This chapter describes ways of installing and removing software
packages. There are several ways of doing both. Here we discuss
installation and removal of pre-built software, such as Debian
packages, and installation of source that must be built by you.
12.1 What a Package Maintenance Utility Does
An application or utility program usually involves quite a few
files. It might include libraries, data files like game scenarios or
icons, configuration files, manual pages, and documentation. When
you install the program, you want to make sure you have all the
files you need in the right places.
You’d also like to be able to uninstall the program. When you
uninstall, you want to be sure all the associated files are deleted.
However, if a program you still have on the system needs those
files, you want to be sure you keep them.
Finally, you’d like to be able to upgrade a program. When you
upgrade, you want to delete obsolete files and add new ones, without
breaking any part of the system.
The Debian package system solves these problems. It allows you to
install, remove, and upgrade software _packages_, which are neat
little bundles containing the program files and information that
helps the computer manage them properly. Debian packages have
filenames ending in the extension .deb, and they’re available on the
FTP site or on your official Debian CD-ROM.
12.2 dpkg
The simplest way to install a single package you’ve downloaded is
with the command dpkg -i (short for dpkg -install). Say you’ve
downloaded the package icewm_0.8.12-1.deb and you’d like to install
it. First log on as root, and then type dpkg -i icewm_0.8.12-1.deb,
and icewm version 0.8.12 will be installed. If you already had an
older version, dpkg will upgrade it rather than installing both
versions at once.
If you want to remove a package, you have two options. The first is
most intuitive: dpkg -r icewm. This will remove the icewm package
(-r is short for -remove). Note that you give only the icewm for
-remove, whereas -install requires the entire .deb filename.
-remove will leave configuration files for the package on your
system. A configuration file is defined as any file you might have
edited in order to customize the program for your system or your
preferences. This way, if you later reinstall the package, you won’t
have to set everything up a second time.
However, you might want to erase the configuration files too, so
dpkg also provides a -purge option. dpkg -purge icewm will
permanently delete every last file associated with the icewm
package.
12.3 dselect
dselect is a great front-end for dpkg. dselect provides a menu
interface for dpkg, and can automatically fetch the appropriate
files from a CD-ROM or Internet FTP site. For details on using
dselect, see section 3.20 on page [*].
12.4 Compiling Software
Many programs come in source format, often in tar.gz form. First,
you must unpack the tar.gz file; for details on doing this, see
section 10.3.1 on page [*]. Before you can compile the package,
you’ll need to have gcc, libc6-dev, and other relevant “-dev”
packages installed; most of these are listed in the devel area in
dselect.
With the appropriate packages installed, cd into the directory that
tar created for you. At this point, you’ll need to read the
installation instructions. Most programs provide an INSTALL or
README file that will tell you how to proceed.
13. Advanced Topics
By now, you should have a strong base for which to build your
GNU/Linux skills on. In this chapter we cover some very useful
information regarding some advanced GNU/Linux features.
13.1 Regular Expressions
A regular expression is a description of a set of characters. This
description can be used to search through a file by looking for text
that matches the regular expression. Regular expressions are
analogous to shell wildcards (see section 6.6 on page [*]), but they
are both more complicated and more powerful.
A regular expression is made up of text and _metacharacters_. A
metacharacter is just a character with a special meaning.
Metacharacters include the following: . * [] - \^ $.
If a regular expression contains only text (no metacharacters), it
matches that text. For example, the regular expression “my regular
expression” matches the text “my regular expression,” and nothing
else. Regular expressions are usually case sensitive.
You can use the egrep command to display all lines in a file that
contain a regular expression. Its syntax is as follows:
egrep ’regexp’ filename1 ...
The single quotation marks are not always needed, but they never
hurt.
For example, to find all lines in the GPL that contain the word GNU,
you type
egrep ’GNU’ /usr/doc/copyright/GPL
egrep will print the lines to standard output. If you want all lines
that contain freedom followed by some indeterminate text, followed
by GNU, you can do this:
egrep ’freedom.*GNU’ /usr/doc/copyright/GPL
The . means “any character,” and the * means “zero or more of the
preceding thing,” in this case “zero or more of any character.” So
.* matches pretty much any text at all. egrep only matches on a
line-by-line basis, so freedom and GNU have to be on the same line.
Here’s a summary of regular expression metacharacters:
. Matches any single character except newline.
* Matches zero or more occurrences of the preceding thing. So the
expression a* matches zero or more lowercase a, and .* matches zero
or more characters.
[_characters_] The brackets must contain one or more characters; the
whole bracketed expression matches exactly one character out of the
set. So [abc]matches one a, one b, or one c; it does not match zero
characters, and it does not match a character other than these
three.
^ Anchors your search at the beginning of the line. The expression
^The matches The when it appears at the beginning of a line; there
can’t be spaces or other text before The. If you want to allow
spaces, you can permit 0 or more space characters like this: ^ *The.
$ Anchors at the end of the line. end$ requires the text end to be
at the end of the line, with no intervening spaces or text.
[^_characters_] This reverses the sense of a bracketed character
list. So [^abc] matches any single character, _except_ a, b, or c.
[_character-character_] You can include ranges in a bracketed
character list. To match any lowercase letter, use [a-z]. You can
have more than one range; so to match the first three or last three
letters of the alphabet, try [a-cx-z]. To get any letter, any case,
try [a-zA-Z]. You can mix ranges with single characters and with the
^metacharacter; for example, [^a-zBZ]means “anything except a
lowercase letter, capital B, or capital Z.”
() You can use parentheses to group parts of the regular expression,
just as you do in a mathematical expression.
|| means “or.” You can use it to provide a series of
alternative expressions. Usually you want to put the alternatives in
parentheses, like this: c(ad|ab|at)matches cad or cab or cat. Without
the parentheses, it would match cad or ab or at instead
\ Escapes any special characters; if you want to find a literal *,
you type \*. The slash means to ignore *’s usual special meaning.
Here are some more examples to help you get a feel for things:
c.pe matches cope, cape, caper.
c\ .pe matches c.pe, c.per.
sto*p matches stp, stop, stoop.
car.*n matches carton, cartoon, carmen.
xyz.* matches xyz and anything after it; some tools, like egrep,
only match until the end of the line.
^The matches The at the beginning of a line.
atime$ matches atime at the end of a line.
^Only$ matches a line that consists solely of the word Only—no
spaces, no other characters, nothing. Only Only is allowed.
b[aou]rn matches barn, born, burn.
Ver[D-F] matches VerD, VerE, VerF.
Ver[^0-9] matches Ver followed by any non-digit.
the[ir][re] matches their, therr, there, theie.
[A-Za-z][A-Za-z]* matches any word which consists of only letters,
and at least one letter. It will not match numbers or spaces.
13.2 Advanced Files
Now that you have a basic understanding of files, it is time to
learn more advanced things about them.
13.2.1 The Real Nature of Files: Hard Links and Inodes
Each file on your system is represented by an _inode_ (for
Information Node; pronounced “eye-node”). An inode contains all the
information about the file. However, the inode is not directly
visible. Instead, each inode is linked into the filesystem by one or
more _hard links_. Hard links contain the name of the file and the
inode number. The inode contains the file itself, i.e., the location
of the information being stored on disk, its access permissions, the
file type, and so on. The system can find any inode if it has the
inode number.
A single file can have more than one hard link. What this means is
that multiple filenames refer to the same file (that is, they are
associated with the same inode number). However, you can’t make hard
links across filesystems: All hard references to a particular file
(inode) must be on the same filesystem. This is because each
filesystem has its own set of inodes, and there can be duplicate
inode numbers on different filesystems.
Because all hard links to a given inode refer to _the same file_,
you can make changes to the file, referring to it by one name, and
then see those changes when referring to it by a different name. Try
this:
cd; echo "hello" > firstlink
cd to your home directory and create a file called firstlink
containing the word “hello.” What you’ve actually done is redirect
the output of echo (echo just echoes back what you give to it),
placing the output in firstlink. See the chapter on shells for a
full explanation.
cat firstlink
Confirms the contents of firstlink.
ln firstlink secondlink
Creates a hard link: secondlink now points to the same inode as
firstlink.
cat secondlink
Confirms that secondlink is the same as firstlink.
ls -l
Notice that the number of hard links listed for firstlink and
secondlinkfiles!inodes is 2.
echo "change" >> secondlink
This is another shell redirection trick (don’t worry about the
details). You’ve appended the word “change” to secondlink. Confirm
this with cat secondlink.
cat firstlink
firstlink also has the word “change” appended! That’s because
firstlink and secondlink refer to _the same file_. It doesn’t matter
what you call it when you change it.
chmod a+rwx firstlink
Changes permissions on firstlink. Enter the command ls -l to confirm
that permissions on secondlink were also changed. This means that
permissions information is stored in the inode, not in links.
rm firstlink
Deletes this link. This is a subtlety of rm. It really removes
links, not files. Now type ls -l and notice that secondlink is still
there. Also notice that the number of hard links for secondlink has
been reduced to one.
rm secondlink
Deletes the other link. When there are no more links to a file,
Linux deletes the file itself, that is, its inode.
All files work like this—even special types of files such as devices
(e.g. /dev/hda).
A directory is simply a list of filenames and inode numbers, that
is, a list of hard links. When you create a hard link, you’re just
adding a name-number pair to a directory. When you delete a file,
you’re just removing a hard link from a directory.
13.2.2 Types of Files
One detail we’ve been concealing up to now is that the Linux kernel
considers nearly everything to be a file. That includes directories
and devices: They’re just special kinds of files.
As you may remember, the first character of an ls -l display
represents the type of the file. For an ordinary file, this will be
simply -. Other possibilities include the following:
ddirectory
lsymbolic link
bblock device
ccharacter device
pnamed pipe
ssocket
Symbolic Links
Symbolic links (also called “symlinks” or “soft links”) are the
other kind of link besides hard links. A symlink is a special file
that “points to” a hard link on any mounted filesystem. When you try
to read the contents of a symlink, it gives the contents of the file
it’s pointing to rather than the contents of the symlink itself.
Because directories, devices, and other symlinks are types of files,
you can point a symlink at any of those things.
So a hard link is a filename and an inode number. A file is really
an inode: a location on disk, file type, permissions mode, etc. A
symlink is an inode that contains the name of a hard link. A symlink
pairs one filename with a second filename, whereas a hard link pairs
a filename with an inode number.
All hard links to the same file have equal status. That is, one is
as good as another; if you perform any operation on one, it’s just
the same as performing that operation on any of the others. This is
because the hard links all refer to the same inode. Operations on
symlinks, on the other hand, sometimes affect the symlink’s own
inode (the one containing the name of a hard link) and sometimes
affect the hard link being pointed to.
There are a number of important differences between symlinks and
hard links.
Symlinks can cross filesystems. This is because they contain
complete filenames, starting with the root directory, and all
complete filenames are unique. Because hard links point to inode
numbers, and inode numbers are unique only within a single
filesystem, they would be ambiguous if the filesystem wasn’t known.
You can make symlinks to directories, but you can’t make hard links
to them. Each directory has hard links—its listing in its parent
directory, its . entry, and the .. entry in each of its
subdirectories—but to impose order on the filesystem, no other hard
links to directories are allowed. Consequently, the number of files
in a directory is equal to the number of hard links to that
directory minus two (you subtract the directory’s name and the .
link). comparing!hard links and symlinks You can only make a hard
link to a file that exists, because there must be an inode number to
refer to. However, you can make a symlink to any filename, whether
or not there actually is such a filename.
Removing a symlink removes only the link. It has no effect on the
linked-to file. Removing the only hard link to a file removes the
file.
Try this:
cd; ln -s /tmp/me MyTmp
cd to your home directory. ln with the -s option makes a symbolic
link - in this case, one called MyTmp that points to the filename
/tmp/me.
ls -l MyTmp
Output should look like this:
lrwxrwxrwx 1 havoc havoc 7 Dec 6 12:50 MyTmp -> /tmp/me
The date and user/group names will be different for you, of course.
Notice that the file type is l, indicating that this is a symbolic
link. Also notice the permissions: Symbolic links always have these
permissions. If you attempt to chmod a symlink, you’ll actually
change the permissions on the file being pointed to.
chmod 700 MyTmp
You will get a No such file or directory error, because the file
/tmp/me doesn’t exist. Notice that you could create a symlink to it
anyway.
mkdir /tmp/me
Creates the directory /tmp/me.
chmod 700 MyTmp
Should work now.
touch MyTmp/myfile
Creates a file in MyTmp.
ls /tmp/me
The file is actually created in /tmp/me.
rm MyTmp
Removes the symbolic link. Notice that this removes the link, not
what it points to. Thus you use rm not rmdir.
rm /tmp/me/myfile; rmdir /tmp/me
Lets you clean up after yourself. symlinks!removing
Device Files
Device files refer to physical or virtual devices on your system,
such as your hard disk, video card, screen, and keyboard. An example
of a virtual device is the console, represented by /dev/console.
There are two kinds of devices:character and block. _Character
devices_ can be accessed one character at a time. Remember the
smallest unit of data that can be written to or read from the device
is a character (byte).
_Block devices_ must be accessed in larger units called blocks,
which contain a number of characters. Your hard disk is a block
device.
You can read and write device files just as you can from other kinds
of files, though the file may well contain some strange
incomprehensible-to-humans gibberish. Writing random data to these
files is probably a bad idea. Sometimes it’s useful, though. For
example, you can dump a postscript file into the printer device
/dev/lp0 or send modem commands to the device file for the
appropriate serial port.
/dev/null
/
/
/
/dev/null is a special device file that discards anything you write
/to it.
If you don’t want something, throw it in /dev/null. It’s essentially
a bottomless pit. If you read /dev/null, you’ll get an end-of-file
(EOF) character immediately. /dev/zero is similar, except that you
read from it you get the \0 character (not the same as the number
zero).
Named Pipes (FIFOs)
A named pipe is a file that acts like a pipe. You put something into
the file, and it comes out the other end. Thus it’s called a FIFO,
or First-In-First-Out, because the first thing you put in the pipe
is the first thing to come out the other end.
If you write to a named pipe, the process that is writing to the
pipe doesn’t terminate until the information being written is read
from the pipe. If you read from a named pipe, the reading process
waits until there’s something to read before terminating. The size
of the pipe is always zero: It doesn’t store data, it just links two
processes like the shell |. However, because this pipe has a name,
the two processes don’t have to be on the same command line or even
be run by the same user.
You can try it by doing the following:
cd; mkfifo mypipe
Makes the pipe.
echo "hello" > mypipe &
Puts a process in the background that tries to write “hello” to the
pipe. Notice that the process doesn’t return from the background; it
is waiting for someone to read from the pipe.
cat mypipe
At this point, the echo process should return, because cat read from
the pipe, and the cat process will print hello.
rm mypipe
You can delete pipes just like any other file.
Sockets
Sockets are similar to pipes, only they work over the network. This
is how your computer does networking. You may have heard of
“WinSock,” which is sockets for Windows.
We won’t go into these further because you probably won’t have
occasion to use them unless you’re programming. However, if you see
a file marked with type son your computer, you know what it is.
13.2.3 The proc Filesystem
The Linux kernel makes a special filesystem available, which is
mounted under /proc on Debian systems. This is a “pseudo-filesystem”
because it doesn’t really exist on any of your physical devices.
The proc filesystem contains information about the system and
running processes. Some of the “files” in /proc are reasonably
understandable to humans (try typing cat /proc/meminfo or cat
/proc/cpuinfo); others are arcane collections of numbers. Often,
system utilities use these to gather information and present it to
you in a more understandable way.
People frequently panic when they notice one file in particular—
/proc/kcore —which is generally huge. This is (more or less) a copy
/of
the contents of your computer’s memory. It’s used to debug the
kernel. It doesn’t actually exist anywhere, so don’t worry about its
size.
If you want to know about all the things in /proc, type man 5 proc.
13.2.4 Large-Scale Copying
Sometimes you may want to copy one directory to another location.
Maybe you’re adding a new hard disk and you want to copy /usr/local
to it. There are several ways you can do this.
The first is to use cp. The command cp -a will tell cp to do a copy
preserving all the information it can. So, you might use
cp -a /usr/local /destination
However, there are some things that cp -a won’t catch[1]. So, the
best way to do a large copy job is to chain two tar commands
together, like so:
[1] Sparse files and hard links are two examples.
tar -cSpf - /usr/local | tar -xvSpf -
-C /destination
The first tar command will archive the existing directory and pipe
it to the second. The second command will unpack the archive into
the location you specify with -C.
13.3 Security
Back in section 7.1 on page [*], we discussed file permissions in
Linux. This is a fundamental way to keep your system secure. If you
are running a multi-user system or a server, it is important to make
sure that permissions are correct. A good rule of thumb is to set
files to have the minimum permissions necessary for use.
If you are running a network server, there are some other things to
be aware of as well. First, you ought to uninstall or turn off any
network services you’re not using. A good place to start is the file
/etc/inetd.conf; you can probably disable some of these. For most
/network
services, it’s also possible to control who has access to them; the
/etc/hosts.allow and /etc/hosts.deny files (documented in
man 5 hosts_access) can control who has access to which services.
You also ought to keep up-to-date with patches or updates to Debian;
these can be found on your nearest Debian FTP mirror.
Some other commonsense rules apply:
◼ Never tell anyone your password.
◼ Never send your password in cleartext across the Internet by
using something like telnet or FTP. Instead, use encrypted
protocols or avoid logging in remotely.
◼ Avoid using root as much as possible.
◼ Don’t install untrusted software, and don’t install it as root.
◼ Avoid making things world-writable whenever possible. /tmp is
one exception to this rule.
While this is probably not of as much use to somebody not running a
server, it is still pays to know a bit about security. Debian’s
security mechanism is what protects your system from many viruses.
13.4 Software Development with Debian
Debian makes a great platform for software development and
programming. Among the languages and near-languages it supports are:
C, C++, Objective-C, Perl, Python, m4, Ada, Pascal, Java, awk,
Tcl/Tk, SQL, assembler, Bourne shell, csh, and more. Writing
programs is beyond the scope of this book, but here are some of the
more popular development programs in Debian:
gcc The GNU C Compiler, a modern optimizing C compiler.
g++ The C++ compiler from the gcc line.
cpp The C preprocessor from gcc.
perl The Perl interpreter. Perl is a great “glue” language.
gdb GNU Debugger, used to debug programs in many different
languages.
gprof Used for profiling, this program helps you to find ways to
improve the performance of your programs.
emacs GNU Emacs is a programmers’ editor and IDE.
as The GNU Assembler.
II. Reference
A. Reading Documentation and Getting Help
A.1 Kinds of Documentation
On Debian systems, you can find documentation in at least the
following places:
◼ man pages, read with the man command.
◼ info pages, read with the info command.
◼ The /usr/doc/_package_ directories, where package is the name of
the Debian package.
Tip:
zless is useful for reading the files in /usr/doc; see section
8.1 on page [*] for details.
◼ /usr/doc/HOWTO/contains the Linux Documentation Project’s HOWTO
documents, if you’ve installed the Debian packages containing
them.
◼ Many commands have an -h or -help option. Type the command name
followed by one of these options to try it.
◼ The Debian Documentation Project[1] has written some manuals.
◼ The Debian support page[2] has a FAQ and other resources. You
can also try the Linux web site[3].
[1]
http://www.debian.org/~elphick/ddp/
[2]
http://www.debian.org/support/
[3]
http://www.linux.org
The confusing variety of documentation sources exists for many
reasons. For example, info is supposed to replace man, but man
hasn’t disappeared yet. However, it’s nice to know that so much
documentation exists!
So where to look for help? Here are some suggestions:
◼ Use the man pages and the -help or -h option to get a quick
summary of a command’s syntax and options. Also use man if a
program doesn’t yet have an info page.
◼ Use info if a program has info documentation.
◼ If neither of those works, look in /usr/doc/_packagename_.
◼ /usr/doc/_packagename_ often has Debian-specific information,
even if there’s a man page or info page.
◼ Use the HOWTOs for instructions on how to set up a particular
thing or for information on your particular hardware. For example,
the Ethernet HOWTO has a wealth of information on Ethernet cards,
and the PPP HOWTO explains in detail how to set up PPP.
◼ Use the Debian Documentation Project manuals for conceptual
explanations and Debian-specific information.
◼ If all else fails, ask someone. See section A.1.3 on page [*].
Using man pages is discussed above in section 5.1 on page [*].
It’s very simple: press the space bar to go to the next page, and
press q to quit reading. Using info, viewing files in /usr/doc,
and asking for help from a person are all discussed in the
remainder of this chapter.
A.1.1 Using info
info is the GNU documentation viewer. Some programs provide
documentationin info format, and you can use info to view that
documentation. You can start up the viewer by simply typing info, or
by supplying a topic as well:
info emacs
You can also bring up the information on info itself, which includes
a tutorial, like so:
info info
Now, you may navigate with these keys:
arrows
Move the cursor around the document
m RET
Select the menu item that’s at the cursor
u
Move “up” in the document
n
Move to the next page
p
Move to the previous page
s
Search for something
g
Go to a specific page
q
Quit info
You might notice that the top line of the screen indicates the next,
previous, and “up” pages, corresponding nicely to the actions for
the n, p, and u keys.
A.1.2 HOWTOs
In addition to their books, the Linux Documentation Project has made
a series of short documents describing how to set up particular
aspects of GNU/Linux. For instance, the SCSI-HOWTO describes some of
the complications of using SCSI—a standard way of talking to
devices—with GNU/Linux. In general, the HOWTOs have more specific
information about particular hardware configurations and will be
more up to date than this manual.
There are Debian packages for the HOWTOs. doc-linux-text contains
the various HOWTOs in text form; the doc-linux-html package contains
the HOWTOs in (surprise!) browsable HTML format. Note also that
Debian has packaged translations of the HOWTOs in various languages
that you may prefer if English is not your native language. Debian
has packages for the German, French, Spanish, Italian, Japanese,
Korean, Polish, Swedish and Chinese versions of the HOWTOs. These
are usually available in the package doc-linux-_languagecode_, where
_languagecode_ is fr for French, es for Spanish, etc. If you’ve
installed one of these, you should have them in
/usr/doc/HOWTO. However, you may be able to find more recent
/versions on
the Net at the LDP homepage[4].
[4]
http://www.metalab.unc.edu/LDP/
A.1.3 Personal Help
The correct place to ask for help with Debian is the debian-user
mailing list at
[email protected]. If you know how to use
IRC (Internet Relay Chat), you can use the #debian channel on
irc.debian.org. You can find general GNU/Linux help on the
comp.os.linux.* USENET hierarchy. It is also possible to hire paid
consultants to provide guaranteed support services. The Debian
website[5] has more information on many of these resources.
[5]
http://www.debian.org/
Again, please _do not_ ask the authors of this book for help. We
probably don’t know the answer to your specific problem anyway; if
you mail debian-user, you will get higher-quality responses, and
more quickly.
Always be polite and make an effort to help yourself by reading the
documentation. Remember, Debian is a volunteer effort and people are
doing you a favor by giving their time to help you. Many of them
charge hundreds of dollars for the same services during the day.
Tips for asking questions
◼ Read the obvious documentation first. Things like command
options and what a command does will be covered there. This
includes manpages and info documentation.
◼ Check the HOWTO documents if your question is about setting up
something such as PPP or Ethernet.
◼ Try to be sure the answer isn’t in this book.
◼ Don’t be afraid to ask, after you’ve made a basic effort to look
it up.
◼ Don’t be afraid to ask for conceptual explanations, advice, and
other things not often found in the documentation.
◼ Include any information that seems relevant. You’ll almost
always want to mention the version of Debian you’re using. You may
also want to mention the version of any pertinent packages: The
command dpkg -l _packagename_ will tell you this. It’s also useful
to say what you’ve tried so far and what happened. Please include
the exact error messages, if any.
◼ Don’t apologize for being new to Linux. There’s no reason
everyone should be a GNU/Linux expert to use it, any more than
everyone should be a mechanic to use a car.
◼ Don’t post or mail in HTML. Some versions of Netscape and
Internet Explorer will post in HTML rather than plain text. Most
people will not even read these posts because the posts are
difficult to read in most mail programs. There should be a setting
somewhere in the preferences to disable HTML.
◼ Be polite. Remember that Debian is an all-volunteer effort, and
anyone who helps you is doing so on his or her time out of
kindness.
◼ Re-mail your question to the list if you’ve gotten no responses
after several days. Perhaps there were lots of messages and it was
overlooked. Or perhaps no one knows the answer—if no one answers
the second time, this is a good bet. You might want to try
including more information the second time.
◼ Answer questions yourself when you know the answer. Debian
depends on everyone doing his or her part. If you ask a question,
and later on someone else asks the same question, you’ll know how
to answer it. Do so!
A.1.4 Getting Information from the System
When diagnosing problems or asking for help, you’ll need to get
information about your system. Here are some ways to do so:
◼ Examine the files in /var/log/.
◼ Examine the output of the dmesg command.
◼ Run uname -a.
B. Troubleshooting
In Debian, as in life, things don’t always work as you might expect
or want them to. While Debian has a well-deserved reputation for
being rock-solid and stable, sometimes its reaction to your commands
may be unexpected. Here, we try to shed some light on the most
common problems that people encounter.
B.1 Common Difficulties
This section provides some tips for handling some of the most
frequently experienced difficulties users have encountered.
B.1.1 Working with Strangely-Named Files
Occasionally, you may find that you have accidentally created a file
that contains a character not normally found in a filename. Examples
of this could include a space, a leading hyphen, or maybe a
quotation mark. You may find that accessing, removing, or renaming
these files can be difficult.
Here are some tips to help you:
◼ Try enclosing the filename in single quotation marks, like this:
less ’File With Spaces.txt’
◼ Insert a ./ before the filename:
less ’./-a strange file.txt’
◼ Use wildcards:
less File?With?Spaces.txt
◼ Use a backslash before each unusual character:
less File\ With\ Spaces.txt
B.1.2 Printing
One common source of trouble is the printing system in Debian.
Traditionally, printing has been a powerful but complex aspect of
Unix. However, Debian makes it easier. An easy way to print is with
the package called magicfilter. magicfilter will ask you a few
questions about your printer and then configure it for you. If you
are having troubles printing, give magicfilter a try.
B.1.3 X Problems
Many questions revolve around X. Here are some general tips for
things to try if you are having difficulties setting up the X Window
system:
◼ For mouse problems, run XF86Setup and try the PS/2, Microsoft,
MouseSystems, and Logitech options. Most mice will fit under one
of these. Also, the device for your mouse is /dev/psaux for PS/2
mice and a serial port such as /dev/ttyS0 for serial mice.
◼ If you don’t know what video chipset you have, try running
SuperProbe; it can often figure this out for you.
◼ If your screen doesn’t have a lot of color, try selecting a
different video card or tell X how much video RAM you have.
◼ If your screen goes blank or has unreadable text when you start
X, you probably selected an incorrect refresh rate. Go back to
XF86Setup or xf86config and double-check those settings.
◼ xvidtune can help if the image on the screen is shifted too far
to the left or right, is too high or low, or is too narrow or
wide.
◼ xdpyinfo can give information about a running X session.
◼ XF86Setup can set your default color depth.
◼ You can select your default window manager by editing
/etc/X11/window-managers.
/
◼ /var/log/xdm-errors can contain useful information if you are
having trouble getting xdm to start properly.
As a final reminder, try the XF86Setup or xf86config tools for
configuring or reconfiguring X for your hardware.
B.2 Troubleshooting the Boot Process
If you have problems during the boot process, such as the kernel
hangs during the boot process, the kernel doesn’t recognize
peripherals you actually have, or drives are not recognized
properly, the first things to check are the boot parameters. They
can be found by pressing F1 when booting from the rescue disk.
Often, problems can be solved by removing add-ons and peripherals
and then booting again. Internal modems, sound cards, and
Plug-n-Play devices are especially problematic.
Tecras and other notebooks, and some non-portables fail to flush the
cache when switching on the A20 gate, which is provoked by bzImage
kernels but not by zImage kernels. If your computer suffers from
this problem, you’ll see a message during boot saying A20 gating
failed. In this case, you’ll have to use the ‘tecra’ boot images.
If you still have problems, please submit a bug report. Send an
email to
[email protected]. You _must_ include the following as
the first lines of the email:
Package: boot-floppies
Version: _version_
Make sure you fill in version with the version of the boot-floppies
set that you used. If you don’t know the version, use the date you
downloaded the floppies, and include the distribution you got them
from (e.g., “stable” or “frozen”).
You should also include the following information in your bug
report:
architecture i386
model your general hardware vendor and model
memory amount of RAM
scsi SCSI host adapter, if any
cd-rom CD-ROM model and interface type, i.e., ATAPI
network card network interface card, if any
pcmcia details of any PCMCIA devices
Depending on the nature of the bug, it also might be useful to
report the disk model, the disk capacity, and the model of video
card.
In the bug report, describe what the problem is, including the last
visible kernel messages in the event of a kernel hang. Describe the
steps you performed that put the system into the problem state.
C. Booting the System
This appendix describes what happens during the GNU/Linux boot
process.
How you boot your system depends on how you set things up when you
installed Debian. Most likely, you just turn the computer on. But
you may have to insert a floppy disk first.
Linux is loaded by a program called LILO, or LInux LOader. LILO can
also load other operating systems and ask you which system you’d
like to load.
The first thing that happens when you turn on an Intel PC is that
the BIOS executes. BIOS stands for Basic Input Output System. It’s a
program permanently stored in the computer on read-only chips. It
performs some minimal tests and then looks for a floppy disk in the
first disk drive. If it finds one, it looks for a “boot sector” on
that disk and starts executing code from it, if there is any. If
there is a disk but no boot sector, the BIOS will print a message
like this: Non-system disk or disk error. Removing the disk and
pressing a key will cause the boot process to resume.
If there isn’t a floppy disk in the drive, the BIOS looks for a
master boot record (MBR) on the hard disk. It will start executing
the code found there, which loads the operating system. On GNU/Linux
systems, LILO can occupy the MBR and will load GNU/Linux.
Thus, if you opted to install LILO on your hard drive, you should
see the word LILO as your computer starts up. At that point, you can
press the left Shift key to select which operating system to load or
press Tab to see a list of options. Type in one of those options and
press Enter. LILO will boot the requested operating system.
If you don’t press the Shift key, LILO will automatically load the
default operating system after about 5 seconds. If you like, you can
change what system LILO loads automatically, which systems it knows
how to load, and how long it waits before loading one automatically.
If you didn’t install LILO on your hard drive, you probably created
a boot disk. The boot disk will have LILO on it. All you have to do
is insert the disk before you turn on your computer, and the BIOS
will find it before it checks the MBR on the hard drive. To return
to a non-Linux OS, take out the boot disk and restart the computer.
From Linux, be sure you follow the proper procedure for restarting;
see section 4.5 on page [*] for details.
LILO loads the Linux kernel from disk and then lets the kernel take
over. (The kernel is the central program of the operating system,
which is in control of all other programs.) The kernel discards the
BIOS and LILO.
On non-Intel platforms, things work a little differently. But once
you boot, everything is more or less the same.
Linux looks at the type of hardware it’s running on. It wants to
know what type of hard disks you have, whether or not you have a bus
mouse, whether or not you’re on a network, and other bits of trivia
like that. Linux can’t remember things between boots, so it has to
ask these questions each time it starts up. Luckily, it isn’t asking
_you_ these questions—it’s asking the hardware! While it boots, the
Linux kernel will print messages on the screen describing what it’s
doing.
The query process can cause problems with your system, but if it was
going to, it probably would have when you first installed GNU/Linux.
If you’re having problems, consult the installation instructions or
ask questions on a mailing list.
The kernel merely manages other programs, so once it is satisfied
everything is okay, it must start another program to do anything
useful. The program the kernel starts is called init. After the
kernel starts init, it never starts another program. The kernel
becomes a manager and a provider of services.
Once init is started, it runs a number of scripts (files containing
commands), which prepare the system to be used. They do some routine
maintenance and start up a lot of programs that do things like
display a login prompt, listen for network connections, and keep a
log of the computer’s activities.
D. The GNU General Public License
GNU GENERAL PUBLIC LICENSE
Version 2, June 1991
Copyright (C) 1989, 1991 Free Software Foundation, Inc. 59
Temple Place, Suite 330, Boston, MA 02111-1307 USA
Everyone is permitted to copy and distribute verbatim
copies of this license document, but changing it is not
allowed.
Preamble
The licenses for most software are designed to take away
your freedom to share and change it. By contrast, the GNU
General Public License is intended to guarantee your
freedom to share and change free software-to make sure the
software is free for all its users. This General Public
License applies to most of the Free Software Foundation’s
software and to any other program whose authors commit to
using it. (Some other Free Software Foundation software
is covered by the GNU Library General Public License
instead.) You can apply it to your programs, too.
When we speak of free software, we are referring to
freedom, not price. Our General Public Licenses are
designed to make sure that you have the freedom to
distribute copies of free software (and charge for this
service if you wish), that you receive source code or can
get it if you want it, that you can change the software or
use pieces of it in new free programs; and that you know
you can do these things.
To protect your rights, we need to make restrictions that
forbid anyone to deny you these rights or to ask you to
surrender the rights. These restrictions translate to
certain responsibilities for you if you distribute copies
of the software, or if you modify it.
For example, if you distribute copies of such a program,
whether gratis or for a fee, you must give the recipients
all the rights that you have. You must make sure that
they, too, receive or can get the source code. And you
must show them these terms so they know their rights.
We protect your rights with two steps: (1) copyright the
software, and (2) offer you this license which gives you
legal permission to copy, distribute and/or modify the
software.
Also, for each author’s protection and ours, we want to
make certain that everyone understands that there is no
warranty for this free software. If the software is
modified by someone else and passed on, we want its
recipients to know that what they have is not the
original, so that any problems introduced by others will
not reflect on the original authors’ reputations.
Finally, any free program is threatened constantly by
software patents. We wish to avoid the danger that
redistributors of a free program will individually obtain
patent licenses, in effect making the program proprietary.
To prevent this, we have made it clear that any patent
must be licensed for everyone’s free use or not licensed
at all.
The precise terms and conditions for copying, distribution
and modification follow.
GNU GENERAL PUBLIC LICENSE
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND
MODIFICATION
0. This License applies to any program or other work which
contains a notice placed by the copyright holder saying it
may be distributed under the terms of this General Public
License. The "Program", below, refers to any such program
or work, and a "work based on the Program" means either
the Program or any derivative work under copyright law:
that is to say, a work containing the Program or a portion
of it, either verbatim or with modifications and/or
translated into another language. (Hereinafter,
translation is included without limitation in the term
"modification".) Each licensee is addressed as "you".
Activities other than copying, distribution and modification
are not covered by this License; they are outside its scope.
The act of running the Program is not restricted, and the
output from the Program is covered only if its contents
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having been made by running the Program). Whether that is
true depends on what the Program does.
1. You may copy and distribute verbatim copies of the
Program’s source code as you receive it, in any medium,
provided that you conspicuously and appropriately publish
on each copy an appropriate copyright notice and
disclaimer of warranty; keep intact all the notices that
refer to this License and to the absence of any warranty;
and give any other recipients of the Program a copy of
this License along with the Program.
You may charge a fee for the physical act of transferring a
copy, and you may at your option offer warranty protection
in exchange for a fee.
2. You may modify your copy or copies of the Program or
any portion of it, thus forming a work based on the
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a) You must cause the modified files to carry prominent
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b) You must cause any work that you distribute or
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running for such interactive use in the most ordinary
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These requirements apply to the modified work as a whole.
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In addition, mere aggregation of another work not based on
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4. You may not copy, modify, sublicense, or distribute the
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Any attempt otherwise to copy, modify, sublicense or
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If any portion of this section is held invalid or
unenforceable under any particular circumstance, the balance
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It is not the purpose of this section to induce you to
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system and a licensee cannot impose that choice.
This section is intended to make thoroughly clear what is
believed to be a consequence of the rest of this License.
8. If the distribution and/or use of the Program is
restricted in certain countries either by patents or by
copyrighted interfaces, the original copyright holder who
places the Program under this License may add an explicit
geographical distribution limitation excluding those
countries, so that distribution is permitted only in or
among countries not thus excluded. In such case, this
License incorporates the limitation as if written in the
body of this License.
9. The Free Software Foundation may publish revised and/or
new versions of the General Public License from time to
time. Such new versions will be similar in spirit to the
present version, but may differ in detail to address new
problems or concerns.
Each version is given a distinguishing version number. If
the Program specifies a version number of this License which
applies to it and "any later version", you have the option
of following the terms and conditions either of that version
or of any later version published by the Free Software
Foundation. If the Program does not specify a version
number of this License, you may choose any version ever
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10. If you wish to incorporate parts of the Program into
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NO WARRANTY
11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE
IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING
THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE
PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND
PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE
PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
NECESSARY SERVICING, REPAIR OR CORRECTION.
12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR
AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY
OTHER PARTY WHO MAY MODIFY AND/ OR REDISTRIBUTE THE
PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR
CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY
TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED
BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO
OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR
OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
DAMAGES.
END OF TERMS AND CONDITIONS
How to Apply These Terms to Your New Programs
If you develop a new program, and you want it to be of the
greatest possible use to the public, the best way to
achieve this is to make it free software which everyone
can redistribute and change under these terms.
To do so, attach the following notices to the program. It
is safest to attach them to the start of each source file
to most effectively convey the exclusion of warranty; and
each file should have at least the "copyright" line and a
pointer to where the full notice is found.
<one line to give the program’s name and a brief idea of
what it does.>
Copyright (C) 19yy <name of author>
This program is free software; you can redistribute it
and/or modify it under the terms of the GNU General
Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your
option) any later version.
This program is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the
implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General
Public License along with this program; if not, write to
the Free Software Foundation, Inc., 59 Temple Place,
Suite 330, Boston, MA 02111-1307 USA
Also add information on how to contact you by electronic and
paper mail.
If the program is interactive, make it output a short notice
like this when it starts in an interactive mode:
Gnomovision version 69, Copyright (C) 19yy name of
author
Gnomovision comes with ABSOLUTELY NO WARRANTY; for
details type ‘show w’.
This is free software, and you are welcome to
redistribute it under certain conditions; type ‘show c’
for details.
The hypothetical commands ‘show w’ and ‘show c’ should show
the appropriate parts of the General Public License. Of
course, the commands you use may be called something other
than ‘show w’ and ‘show c’; they could even be mouse-clicks
or menu items-whatever suits your program.
You should also get your employer (if you work as a
programmer) or your school, if any, to sign a "copyright
disclaimer" for the program, if necessary. Here is a
sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in
the program ‘Gnomovision’ (which makes passes at
compilers) written by James Hacker.
<signature of Ty Coon>, 1 April 1989
Ty Coon, President of Vice
This General Public License does not permit incorporating
your program into proprietary programs. If your program is
a subroutine library, you may consider it more useful to
permit linking proprietary applications with the library.
If this is what you want to do, use the GNU Library General
Public License instead of this License.
Index
$ (dollar sign)
regular expression
Regular Expressions
() (parentheses)
regular expression
Regular Expressions
(caret)
regular expression
Regular Expressions
* (regular expression)
Regular Expressions
* (wildcard)
Filename Expansion
. (regular expression)
Regular Expressions
/ (slash)
root directory
Files and Directories | Files and Directories
/bin directory
Files Present and Their
/etc (directory)
system-wide configuration
System-Wide Versus User-Specific Configuration |
System-Wide Versus User-Specific Configuration
/etc directory
Files Present and Their | Files Present and Their | Files Present
and Their
/etc/X11/Xsession
modifying
Customizing Your X Startup
/root directory
Files Present and Their
/sbin directory
Files Present and Their
/user directory
Files Present and Their
/var directory
Files Present and Their
/tmp directory
Files Present and Their
? wildcard
Filename Expansion
[] (brackets)
regular expression
Regular Expressions
(tilde)
Using Files: A Tutorial
absolute filenames
Files and Directories | Using Files: A Tutorial
abstractions
Introduction to X
Access screen
dselect
Access
accessing
files
Mode
filesystems
Mounting a Filesystem
Help file (installation)
Select
accounts
ordinary user
Create an Ordinary User | Create an Ordinary User
permissions
Permissions | Permissions
example sessions
Permissions in Practice | Permissions in
Practice | Permissions in Practice
file mode
Mode | Mode | Mode
file ownership
File Ownership | File Ownership
root user
Working as Root | Working as Root
superuser
Set the Root Password
user
logging in
First Steps | First Steps
plans
Managing Your Identity | Managing Your
Identity
Acknowledgments
no title
activating
swap partition
Initialize and Activate a | Initialize and Activate a
ae
no title
ae (text editor)
Text Editors | Using ae
alias
Aliases
aliases
Aliases
Alt key
Conventions | Conventions
APM
Shutting Down
APM (Advanced Power Management)
Shutting Down
application software
What Is Debian?
applications
cfdisk
Partition a Hard Disk | Partition a Hard Disk
configuration files
Configuration Files
dbootstrap
Step-by-Step Installation
network configuration
Configure the Network
dselect
Select and Install Profiles | Introduction |
Introduction
Access screen
Access
multi-CD installation
Access
multi-NFS, multi-mount installation
Access
package states
Select | Select
Update screen
Update | Select | Select | Select |
Select
exiting
How to Read This
file managers
Introduction to X
GNU documentation viewer
Using info | Using info
gzip
File Compression with gzip | File Compression with
gzip
multitasking
A Multiuser, Multitasking Operating
system binaries
Files Present and Their
tasks
Select and Install Profiles | Select and Install
Profiles
text editores
Text Editors | Text Editors
text editors
ae
Using ae
archiving utilities
Backup Tools
arguments
The Command Line and
arranging
hard drive
Partitioning Your Hard Drive | Background |
Background
asking technical questions
Personal Help | Tips for asking questions
assigning
job numbers to command lines
Managing Processes with bash
authentication
shadow passwords
Shadow Password Support
automatic filesystem mounting
/etc/fstab: Automating the Mount | /etc/fstab: Automating the
Mount
backing up
disks
Last Chance to Back
backups
performing
Before You Start
utilities
Backup Tools
GNU tar
tar
base system
no title | no title
configuring
Debian Installation Steps | Choosing Your
Installation Media
installation
Install the Base System | Configure the Base System
bash
Managing Processes with bash | Managing Processes with bash
commands
aliases
Aliases
environment variables
setting
Environment Variables | Environment
Variables
Info help system
displaying
Managing Processes with bash
binary executables
comparing to source code
Viewing Text Files
binary files
Working with Text Files
viewing
Viewing Text Files
BIOS (Basic Input/Output System)
Booting the System
black-and-white display
selecting
Select Color or Monochrome
block devices
Device Files | /dev/null
blocks
Device Files
bold face
typographical conventions
Conventions
boot floppies
creating
Make a Boot Floppy
boot loaders
Before You Start
LILO
Make Linux Bootable Directly
boot partition
PC Disk Limitations
boot process
LILO (Linux Loader)
Booting the System
query process
Booting the System
troubleshooting
Troubleshooting the Boot Process
booting
Debian
Booting Debian
from CD-ROM
Choosing Your Installation Media
from floppies
Booting from Floppies
operating systems
multiple
Make Linux Bootable Directly
smoke test
The Moment of Truth
Bourne shell
The Shell
bug reports
submitting
Troubleshooting the Boot Process
built-in dependencies
packages
Select | Select
built-in programs
Where Commands Reside: The
buttons
mouse operation
The Mouse
C shell
The Shell
canceling
selections (dselect)
Select
cd
Using Files: A Tutorial
cd command
Using Files: A Tutorial | Using Files: A Tutorial
CD-ROM
booting from
Choosing Your Installation Media
CD-ROMs
mounting
Example: Mounting a CD-ROM | Example: Mounting a
CD-ROM
unmounting
Example: Mounting a CD-ROM
CDs
multi-CD installation
Access | Access
multi-NFS, multi-mount installation
Access
cfdisk
Partition a Hard Disk | Partition a Hard Disk | Partition a Hard
Disk
Change Directory
see cd
character devices
Device Files | /dev/null
characters
metacharacters
Regular Expressions
clients
X clients
Introduction to X
network transparency
Introduction to X
X windows system
X Clients | X Clients
selecting
Customizing Your X Startup | Customizing
Your X Startup
closing
programs
How to Read This
color display
selecting
Select Color or Monochrome
Comand Line
History
no title
command history
Command History and Editing
command line
Command History and Editing | Command History and Editing | no
title | Describing the Command Line | Describing the Command Line
structure
The Command Line and
command lines
job numbers
assigning
Managing Processes with bash
command-line shell
The Shell | The Shell
commands
aliases
Aliases
arguments
The Command Line and
Bash
wildcards
Tab Completion
cd
Using Files: A Tutorial | Using Files: A Tutorial
documentation
Kinds of Documentation | Kinds of Documentation
info
Using info | Using info
egrep
Regular Expressions
ls
Using Files: A Tutorial | Using Files: A Tutorial |
Dot Files and ls -a
man less
Environment Variables
mkdir
Using Files: A Tutorial
more
Using Files: A Tutorial
parameters
The Command Line and
shell commands
typing
First Steps
su
Working as Root
whoami
Working as Root
commercial software
comparing to proprietary
What Is Free Software?
comparing
binary and text files
Viewing Text Files
crackers and hackers
What Is Free Software?
hard links and symlinks
Symbolic Links
programs and processes
Processes
software
commercial and proprietary
What Is Free Software?
system-wide and user-specific configuration
System-Wide Versus User-Specific Configuration |
System-Wide Versus User-Specific Configuration
compiling
packages
Compiling Software
compressing
files
File Compression with gzip | File Compression with
gzip
Configuration
Base system
no title
comparing system-wide and user-specific
System-Wide Versus User-Specific Configuration |
System-Wide Versus User-Specific Configuration
Device drivers
no title
Modules
no title
networking
Ethernet
Ethernet
PPP
The Easy Way: wvdial | The Easy Way:
wvdial
PCMCIA
no title | Configure PCMCIA Support
system-wide
/etc directory
Files Present and Their
automatic filesystem mounting
/etc/fstab: Automating the Mount |
/etc/fstab: Automating the Mount
networking
Networking | PPP | Preparation
user-specific
dotfiles
System-Wide Versus User-Specific
Configuration
configuring
base system
Debian Installation Steps | Choosing Your
Installation Media
device drivers
Configure Device Driver Modules
keyboard
Configure the Keyboard
network
Configure the Network
packages
Configure
connections
networking
Ethernet
Ethernet
PPP
PPP | Preparation | The Easy Way: wvdial
| The Easy Way: wvdial
consoles
A Multiuser, Multitasking Operating
virtual consoles
Virtual Consoles | Virtual Consoles
controllers
SCSI
partitions, naming
Device Names in Linux
controlling
processes
The Shell | The Shell
conventions
typographical
Conventions | Conventions
spaces
Conventions
copy-and-paste
mouse operation (X)
The Mouse
copying
large-scale
Large-Scale Copying | Large-Scale Copying
crackers
comparing to hackers
What Is Free Software?
creating
accounts
ordinary user
Create an Ordinary User | Create an
Ordinary User
superuser
Set the Root Password
directories
Using Files: A Tutorial
disk images
Creating Floppies from Disk | Creating Floppies from
Disk
plans
Managing Your Identity | Managing Your Identity
csh (C shell)
The Shell
current working directories
Using Files: A Tutorial
Current Working Directory
Using Files: A Tutorial
customizing
X windows system
Customizing Your X Startup
cylinder translation
PC Disk Limitations
daemon
Processes
dbootstrap
Step-by-Step Installation
network configuration
Configure the Network
Debian
booting
Booting Debian
from CD-ROM
Choosing Your Installation Media
Web site
What Is Free Software?
Debian base system
Debian Installation Steps | Choosing Your Installation Media
Debian mailing list
Personal Help | Personal Help
deleting
directories
Using Files: A Tutorial
files
Using Files: A Tutorial
hard links
The Real Nature of
named pipes
Named Pipes (FIFOs)
symlinks
Symbolic Links | Symbolic Links
Deleting Files
see rm
dependencies
packages
Select | Select
deselect
package maintenance
dselect
Devel_comp (profile)
Planning Use of the
developing
Free Software
Social Contract
What Is Free Software?
software
free software
What Is Free Software? | What Is Free
Software?
development
Who Creates Debian?
device drivers
configuring
Configure Device Driver Modules
device files
Device Files | /dev/null
Device Names
no title
devices
Device Names in Linux | Device Names in Linux
abstractions
Introduction to X
base system
installing
Install the Base System | Configure the
Base System
block devices
Device Files | /dev/null
character devices
Device Files | /dev/null
daemons
Processes
files
symlinks
Symbolic Links
filesystems
Concepts
automatic mounting
/etc/fstab: Automating the Mount |
/etc/fstab: Automating the Mount
hard links
The Real Nature of | The Real Nature of
mount points
Mounting a Filesystem
mounting
Mounting a Filesystem | Mounting a
Filesystem | Example: Mounting a CD-ROM
| Example: Mounting a CD-ROM | Removable
Disks (Floppies, Zip
proc
The proc Filesystem
symlinks
Symbolic Links | Symbolic Links |
Symbolic Links
naming
Device Names in Linux
output
redirecting
stdin, stdout, Pipelines, and | stdin,
stdout, Pipelines, and
PCMCIA
configuring
Configure PCMCIA Support
printers
troubleshooting
Printing
SCSI drives
partitions
Device Names in Linux
swap partitions
Recommended Partitioning Scheme | Recommended
Partitioning Scheme
Dialup profile
Planning Use of the
Directories
no title | Files and Directories | Files and Directories | Files
and Directories | Files Present and Their
/etc
Files Present and Their | Files Present and Their |
Files Present and Their
system-wide configuration
System-Wide Versus User-Specific
Configuration | System-Wide Versus
User-Specific Configuration
/root
Files Present and Their
/tmp
Files Present and Their
/user
Files Present and Their
/var
Files Present and Their
contents, displaying
Files Present and Their | Files Present and Their
copying
Large-Scale Copying | Large-Scale Copying
creating
Using Files: A Tutorial
current working directory
Using Files: A Tutorial
file systems
mount points
Mounting a Filesystem
filename expansion patterns
Filename Expansion | Filename Expansion
files
hard links
The Real Nature of | The Real Nature of
inodes
The Real Nature of | The Real Nature of
locating
Finding Files | Finding Files
symlinks
Symbolic Links
filesystems
Concepts
mounting
Mounting a Filesystem | Mounting a
Filesystem | Example: Mounting a CD-ROM
| Example: Mounting a CD-ROM | Removable
Disks (Floppies, Zip
hard links
removing
The Real Nature of
home directory
Files Present and Their
modes
Mode
parent directories
Using Files: A Tutorial
paths
Files and Directories
permissions
example session
Permissions in Practice | Permissions in
Practice | Permissions in Practice
removing
Using Files: A Tutorial
search path (shell)
Where Commands Reside: The | Where Commands Reside:
The
shortcut directories
Using Files: A Tutorial
symlinks
Symbolic Links
system-wide
files, modifying
Files Present and Their
disk blocks
scanning
Initialize and Activate a
disk cache
Shutting Down
disk space
installation requirements
Memory and Disk Space
disks
backing up
Last Chance to Back
boot disks
LILO
Booting the System
boot floppies
creating
Make a Boot Floppy
filesystems
mount points
Mounting a Filesystem
mounting
Mounting a Filesystem | Mounting a
Filesystem | Example: Mounting a CD-ROM
| Example: Mounting a CD-ROM | Removable
Disks (Floppies, Zip
floppies
booting from
Booting from Floppies
images
writing to floppies
Creating Floppies from Disk | Creating
Floppies from Disk
removable
mounting filesystem
Removable Disks (Floppies, Zip
displaying
directory contents
Files Present and Their | Files Present and Their
file contents
Determining a File’s Contents
files
filename expansion pattern
Filename Expansion
Info help system
Managing Processes with bash
mounted filesystems
Example: Mounting a CD-ROM
text files
Viewing Text Files
displays
ae (text editor)
Using ae
dselect
Access screen
Access
X windows system
windows manager
Introduction to X
dividing
partitions
Lossless Repartitioning
documentation
Kinds of Documentation | Kinds of Documentation
GNU General Public License
The GNU General Public | The GNU General Public | The
GNU General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public
HOWTOs
HOWTOs
info
Using info | Using info
DOS (Disk Operating System)
partitioning
Partitioning from DOS or | Lossless Repartitioning |
Debian Installation Steps
Dotfiles
no title | Dot Files and ls -a | System-Wide Versus User-Specific
Configuration
dpkg
no title
package maintenance
dpkg
dselect
Select and Install Profiles | no title | Introduction |
Introduction | Access | no title
Access menu
no title
Access screen
Access
multi-CD installation
Access
package states
Select | Select
packages
configuring
Configure
installing
Install | Install
Select
no title
Select screen
Select | Select | Select | Select | Select
exiting
Select
Update
no title
Update screen
Update
dump
Backup Tools
dump (backup utility
Backup Tools
editing
text
Text Editors | Text Editors
Editors
no title
egrep command
Regular Expressions
Emacs (text editor)
Text Editors | Text Editors
email
bug reports
troubleshooting
Troubleshooting the Boot Process
Debian mailing list
Personal Help | Personal Help
environment
variables
importing
Environment Variables
environment variables
no title | Environment Variables
bash
setting
Environment Variables | Environment
Variables
PATH
Where Commands Reside: The | Where Commands Reside:
The
proxy servers
setting
Access
environments
Environment Variables
error messages
standard error
stdin, stdout, Pipelines, and
X windows system
troubleshooting
Troubleshooting
Ethernet
configuration
Ethernet
example session
permissions
Permissions in Practice | Permissions in Practice |
Permissions in Practice
execute permission
Mode
executing
programs
search path
Where Commands Reside: The | Where
Commands Reside: The
exiting
ae (text editor)
Using ae
programs
How to Read This
Select screen (dselect)
Select
X windows system
Leaving the X Environment | Customizing Your X
Startup | Customizing Your X Startup
expansion patterns
Filename Expansion | Filename Expansion
see also wildcards
Filename Expansion
exporting
shell variables
Environment Variables
variables to environment
Environment Variables
ext2 filesystem
Concepts
extended partitions
PC Disk Limitations | Device Names in Linux
FIFO (first-in-first-out)
Named Pipes (FIFOs)
file manager
Using a File Manager
file managers
icon-based
Introduction to X
file pagers
text files
viewing
Viewing Text Files
file systems
Partitioning Your Hard Drive | Background | Background
filename expansion pattern
Filename Expansion
filename expansion patterns
Filename Expansion
files
no title | Files and Directories | Files and Directories | Files
and Directories
/etc/X11/Xsession
modifying
Customizing Your X Startup
access
Mode
binary
Working with Text Files
viewing
Viewing Text Files
compressing
File Compression with gzip | File Compression with
gzip
configuration files
Configuration Files
contents
displaying
Determining a File’s Contents
current working directory
Using Files: A Tutorial
deleting
Using Files: A Tutorial
device files
Device Files | /dev/null
disk images
Creating Floppies from Disk | Creating Floppies from
Disk
dotfiles
Dot Files and ls -a | System-Wide Versus
User-Specific Configuration
Editors
no title
hard links
The Real Nature of | The Real Nature of
inodes
The Real Nature of
large-scale copying
Large-Scale Copying | Large-Scale Copying
locating
Finding Files | Finding Files
moving
Using Files: A Tutorial
named pipes
Named Pipes (FIFOs)
naming conventions
troubleshooting
Working with Strangely-Named Files
permissions
Permissions | Permissions | Security
example sessions
Permissions in Practice | Permissions in
Practice | Permissions in Practice
mode
Mode | Mode | Mode
ownership
File Ownership | File Ownership
plans
creating
Managing Your Identity | Managing Your
Identity
regular expressions
Regular Expressions | Regular Expressions | Regular
Expressions
sockets
Sockets
symlinks
Symbolic Links
removing
Symbolic Links | Symbolic Links
temporary
Files Present and Their
Text
no title
editing
Text Editors | Text Editors | Using ae
viewing
Viewing Text Files
text files
Working with Text Files
uncompressing
File Compression with gzip
filesystems
Filesystems
automatic mounting
/etc/fstab: Automating the Mount | /etc/fstab:
Automating the Mount
backing up
Backup Tools
GNU tar
tar
ext2
Concepts
hard links
The Real Nature of | The Real Nature of
deleting
The Real Nature of
listing
Example: Mounting a CD-ROM
mount points
Mounting a Filesystem
mounting
Mounting a Filesystem | Mounting a Filesystem |
Example: Mounting a CD-ROM | Example: Mounting a
CD-ROM | Removable Disks (Floppies, Zip
proc
The proc Filesystem
symlinks
Symbolic Links
finding
documentation
Kinds of Documentation | Kinds of Documentation
files
Finding Files | Finding Files
system information
Getting Information from the
finger information
plans
creating
Managing Your Identity
FIPS
Lossless Repartitioning | Lossless Repartitioning
floppies
boot floppies
creating
Make a Boot Floppy
booting from
Booting from Floppies
disk images
writing
Creating Floppies from Disk | Creating
Floppies from Disk
filesystem
mounting
Removable Disks (Floppies, Zip
filesystems
Mounting a Filesystem
Floppy Disks
no title
fonts
selecting
Starting the X Environment
xterm
increasing size
Starting the X Environment
Free Software
What Is Free Software?
developing
What Is Free Software?
Social Contract
What Is Free Software?
Free Software Foundation
What Is Free Software?
fully-qualified filenames
Files and Directories
functionality
What Is Debian?
General Public License
The GNU General Public | The GNU General Public | The GNU General
Public | The GNU General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU General Public |
The GNU General Public | The GNU General Public | The GNU General
Public | The GNU General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU General Public |
The GNU General Public | The GNU General Public | The GNU General
Public | The GNU General Public | The GNU General Public | The GNU
General Public | The GNU General Public
glossary
Glossary
GNOME desktop project
Introduction to X
GNU documentation viewer
Using info | Using info
GNU General Public License
The GNU General Public | The GNU General Public | The GNU General
Public | The GNU General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU General Public |
The GNU General Public | The GNU General Public | The GNU General
Public | The GNU General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU General Public |
The GNU General Public | The GNU General Public | The GNU General
Public | The GNU General Public | The GNU General Public | The GNU
General Public | The GNU General Public
GNU Midnight Commander
Using a File Manager
GNU Project
What Is Debian?
GNU tar
tar
GNU tar (backup utility
Backup Tools
GNU/Linux
multiuser environment
A Multiuser, Multitasking Operating
graphical user interfaces
see GUIs
The X Window System | Introduction to X
GUIs
abstractions
Introduction to X
icon-based file managers
Introduction to X
X Window
The X Window System | Introduction to X
X windows system
clients
X Clients | X Clients
clients, selecting
Customizing Your X Startup | Customizing
Your X Startup
customizing
Customizing Your X Startup
exiting
Leaving the X Environment | Customizing
Your X Startup | Customizing Your X
Startup
mouse operation
The Mouse
starting
Starting the X Environment
troubleshooting
Troubleshooting | X Problems
xdm
Starting the X Environment
gzip
File Compression with gzip | File Compression with gzip
Hacker Ethic
What Is Free Software?
hackers
What Is Free Software?
hard disk
Linux partition
initializing
Initialize a Linux Partition |
Initialize a Linux Partition
partitioning
PC BIOS
PC Disk Limitations
swap partition
initializing
Initialize and Activate a | Initialize
and Activate a
hard disks
partitioning
Lossless Repartitioning | Debian Installation Steps |
Partition a Hard Disk | Partition a Hard Disk
partitions
mounting
Initialize a Linux Partition
scanning
Initialize and Activate a
hard drive
organizing
Partitioning Your Hard Drive | Background |
Background
partition
boot partition
PC Disk Limitations
partitioning
Partitioning Your Hard Drive | Background |
Background
cylinder translation
PC Disk Limitations
root partition
Background
swap partition
Background
hard drives
filesystems
Mounting a Filesystem
LILO
operating system, booting
Booting the System
partitioning
swap partitions
Recommended Partitioning Scheme |
Recommended Partitioning Scheme
partitions
mounting
Mount a Previously-Initialized Partition
hard links
The Real Nature of | The Real Nature of
comparing to symlinks
Symbolic Links | Symbolic Links
deleting
The Real Nature of
symlinks
Symbolic Links
hardware
abstractions
Introduction to X
device files
Device Files | /dev/null
video cards
support for
Supported Hardware
Hardware, supported
no title
Help file (installation)
accessing
Select
help system
HOWTOs
HOWTOs
hierarchies
Concepts
filesystems
Concepts
mount points
Mounting a Filesystem
mounting
Mounting a Filesystem | Mounting a
Filesystem | Example: Mounting a CD-ROM
| Example: Mounting a CD-ROM | Removable
Disks (Floppies, Zip
History
see Command Line History
home directories
Files Present and Their
home directory
Using Files: A Tutorial
HOWTOs
HOWTOs
icon-based file managers
Introduction to X
images (disk)
writing to floppies
Creating Floppies from Disk | Creating Floppies from
Disk
importing
variables to environment
Environment Variables
info
no title | Using info | Using info
Info help system
Managing Processes with bash
initializing
Linux partition
Initialize a Linux Partition | Initialize a Linux
Partition
swap partition
Initialize and Activate a | Initialize and Activate a
inodes
The Real Nature of | The Real Nature of
hard links
removing
The Real Nature of
Installation
backups, performing
Before You Start
base system
Install the Base System | Configure the Base System
base system, configuring
Debian Installation Steps | Choosing Your
Installation Media
boot floppies
creating
Make a Boot Floppy
CD-ROM
no title
device drivers
configuring
Configure Device Driver Modules
disks
backing up
Last Chance to Back
dselect
Introduction
Access screen
Access
Floppies
no title
hard disks
partitioning
Partition a Hard Disk | Partition a Hard
Disk
hard drive
partitioning
Background | Background
partitioning
Partitioning Your Hard Drive
Help file
accessing
Select
kernel
Install Operating System Kernel
keyboard configuration
Configure the Keyboard
Linux partition
initialization
Initialize a Linux Partition |
Initialize a Linux Partition
main menu
Debian GNU/Linux Installation Main
master boot record
Make Linux Bootable Directly
Media
no title
memory requirements
Memory and Disk Space
Menu
no title
monitor display
color, selecting
Select Color or Monochrome
multi-NFS, multi-mount
Access
multi_cd
Access | Access
network
configuring
Configure the Network
packages
Package Installation with dselect
partitioning
Partitioning Prior to Installation | Partitioning
from DOS or | Lossless Repartitioning | Debian
Installation Steps
PCMCIA support
configuring
Configure PCMCIA Support
Prerequisites
no title
profiles
Planning Use of the
selecting
Select and Install Profiles
root password
setting
Set the Root Password
smoke test
The Moment of Truth
swap partition
initialization
Initialize and Activate a | Initialize
and Activate a
tasks
selecting
Select and Install Profiles
time zone
specifying
Configure the Base System
installations
network workstations
Information You Will Need
operating systems, multiple
Before You Start
installing
packages
Install | Install
Internet
Debian mailing list
Personal Help | Personal Help
online manual
viewing
Environment Variables
IRC (Internet Relay Chat)
Debian mailing list
Personal Help | Personal Help
ISPs
PPP
PPP | Preparation
italics
typographical conventions
Conventions
job
Managing Processes with bash
job numbers
assigning to command lines
Managing Processes with bash
jobs
Managing Processes with bash | Managing Processes with bash
listing
Managing Processes with bash
starting
Managing Processes with bash
status
displaying
Managing Processes with bash
suspending
Managing Processes with bash | Managing Processes
with bash
terminating
Managing Processes with bash | Managing Processes
with bash
kernel
boot process
troubleshooting
Troubleshooting the Boot Process
installing
Install Operating System Kernel
PCMCIA
removing
Remove PCMCIA
virtual consoles
Virtual Consoles | Virtual Consoles
kernel:LILO (Linux Loader)
Booting the System | Booting the System
key combinations
dselect
Select
keyboard
configuring
Configure the Keyboard
killing
jobs
Managing Processes with bash | Managing Processes
with bash
X server
Leaving the X Environment
Korn shell
The Shell
languages
programming
Software Development with Debian | Software
Development with Debian
LANs
Ethernet
configuration
Ethernet
large-scale copying
Large-Scale Copying | Large-Scale Copying
legal documentation
GNU General Public License
The GNU General Public | The GNU General Public | The
GNU General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public
licenses
GNU General Public License
The GNU General Public | The GNU General Public | The
GNU General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public
LILO
Make Linux Bootable Directly
LILO (Linux Loader)
Booting the System | Booting the System
limitations
partitions
PC Disk Limitations
Linux
devices
Device Names in Linux | Device Names in Linux |
Device Names in Linux
GNU General Public License
The GNU General Public | The GNU General Public | The
GNU General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public | The GNU General Public | The GNU
General Public
kernel
command line
Describing the Command Line | Describing
the Command Line
disk cache
Shutting Down
virtual console
Virtual Consoles | Virtual Consoles
Linux Documentation Project
Supported Hardware
HOWTOs
HOWTOs
Linux native partition
creating
Partition a Hard Disk | Partition a Hard Disk
Linux partition
initializing
Initialize a Linux Partition | Initialize a Linux
Partition
Linux partitions
mounting
Initialize a Linux Partition | Initialize a Linux
Partition
Linux swap partition
creating
Partition a Hard Disk | Partition a Hard Disk
listing
aliases
Aliases
jobs
Managing Processes with bash
mounted filesystems
Example: Mounting a CD-ROM
processes
Processes
locating
documentation
Kinds of Documentation | Kinds of Documentation
files
Finding Files | Finding Files
system information
Getting Information from the
logging in
First Steps | First Steps
logical partitions
PC Disk Limitations | Device Names in Linux
long form
options
The Command Line and
ls
Using Files: A Tutorial | no title
ls command
Using Files: A Tutorial | Using Files: A Tutorial | Dot Files and
ls -a
mailing list
Debian
Personal Help | Personal Help
main menu
installation
Debian GNU/Linux Installation Main
mainenance
packages
What a Package Maintenance | What a Package
Maintenance
deselect
dselect
dpkg
dpkg
man less command
Environment Variables
man pages
The Command Line and
managing
files
Using a File Manager
manual startup
X windows system
Starting the X Environment
master boot record
installation
Make Linux Bootable Directly
memory
disk cache
Shutting Down
installation requirements
Memory and Disk Space
swap partitions
Recommended Partitioning Scheme | Recommended
Partitioning Scheme
menus
installation
Debian GNU/Linux Installation Main
Partition a Hard Disk
Partition a Hard Disk | Partition a Hard
Disk
messages
error
standard error
stdin, stdout, Pipelines, and
metacharacters
regular expressions
Regular Expressions | Regular Expressions | Regular
Expressions
mkdir command
Using Files: A Tutorial
mode (files)
Mode | Mode | Mode
modifier keys
Conventions | Conventions
modifying
files
hard links
The Real Nature of
modularity
Introduction to X
modules
device drivers
configuring
Configure Device Driver Modules
installation
Install Operating System Kernel
monitor
display color
selecting
Select Color or Monochrome
monochrome display
selecting
Select Color or Monochrome
more command
Using Files: A Tutorial
mount points
Mounting a Filesystem
mounting
CD-ROM
Example: Mounting a CD-ROM | Example: Mounting a
CD-ROM
filesystems
Mounting a Filesystem | Mounting a Filesystem |
Example: Mounting a CD-ROM | Example: Mounting a
CD-ROM | Removable Disks (Floppies, Zip
automatic
/etc/fstab: Automating the Mount |
/etc/fstab: Automating the Mount
floppy disks
Removable Disks (Floppies, Zip
initialized partitions
Mount a Previously-Initialized Partition
partitions
Initialize a Linux Partition | Initialize a Linux
Partition
mouse operation
X windows system
The Mouse
moving
files
Using Files: A Tutorial
msdos filesystem
Concepts
multi-NFS, multi-mount installation
Access
multi_cd installation
Access | Access
multiple operating systems
booting
Make Linux Bootable Directly
multitasking
A Multiuser, Multitasking Operating | A Multiuser, Multitasking
Operating
processes
Processes
Multiuser
A Multiuser, Multitasking Operating
multiuser environment
GNU/Linux
A Multiuser, Multitasking Operating
multiuser environments
virtual console
Virtual Consoles | Virtual Consoles
mv command
Using Files: A Tutorial
named pipes
Named Pipes (FIFOs)
naming
devices
Device Names in Linux | Device Names in Linux |
Device Names in Linux
naming conventions
files
troubleshooting
Working with Strangely-Named Files
navigating
dbootstrap
Step-by-Step Installation
nedit (text editor
Text Editors
netowrks
devices
output, redirecting
stdin, stdout, Pipelines, and | stdin,
stdout, Pipelines, and
network
configuring
Configure the Network
Network Configuration
no title
network transparency
Introduction to X
networking
Networking
Ethernet
configuration
Ethernet
PPP
PPP | Preparation
configuration
The Easy Way: wvdial | The Easy Way:
wvdial
sockets
Sockets
networks
servers
partitioning
Recommended Partitioning Scheme
terminals
A Multiuser, Multitasking Operating
virtual console
Virtual Consoles | Virtual Consoles
workstations
installation
Information You Will Need
X servers
Introduction to X
online manual
builtin programs
Where Commands Reside: The
text, paging
Environment Variables
viewing
Environment Variables
Open Source Software
What Is Free Software?
operating system
booting
LILO (Linux Loader)
Booting the System
kernel
installing
Install Operating System Kernel
operating systems
What Is Debian?
backup tools
Backup Tools
GNU tar
tar
boot loaders
Before You Start
Debian
booting
Booting Debian
functionality
What Is Debian?
GNU Linux
multiuser environment
A Multiuser, Multitasking Operating
installation
partitioning
Partitioning Prior to Installation |
Partitioning from DOS or | Lossless
Repartitioning | Debian Installation
Steps
LILO
Make Linux Bootable Directly
modularity
Introduction to X
multiple installations
Before You Start
multiple, booting
Make Linux Bootable Directly
root password
setting
Set the Root Password
swap partitions
Background
X windows system
troubleshooting
X Problems
options (commands)
The Command Line and
ordinary user accounts
Create an Ordinary User | Create an Ordinary User
organization
files
Files and Directories | Files and Directories
organizing
files
Concepts
hard drive
Partitioning Your Hard Drive | Background |
Background
ouput
redirecting
pipelines
stdin, stdout, Pipelines, and
output
redirecting
stdin, stdout, Pipelines, and | stdin, stdout,
Pipelines, and | stdin, stdout, Pipelines, and
reversing
stdin, stdout, Pipelines, and
overriding
package dependencies
Select
ownership (files)
File Ownership | File Ownership
packages
Glossary
canceling selection (dselect)
Select
compiling
Compiling Software
configuring
Configure
Debian base system
Debian Installation Steps | Choosing Your
Installation Media
dependencies
Select | Select
development
Who Creates Debian?
installation
Package Installation with dselect
multi-CD
Access | Access
multi-NFS, multi-mount
Access
installing
Install | Install
maintenance utilities
What a Package Maintenance | What a Package
Maintenance
deselect
dselect
dpkg
dpkg
profiles
Planning Use of the
see also dselect
Introduction | Introduction
selecting
Select and Install Profiles | Select | Select |
Select
states (dselect)
Select | Select
PAGER environment variable
Environment Variables
parameters
The Command Line and
parent directories
Using Files: A Tutorial
partition
boot partition
PC Disk Limitations
Initialization
no title
Swap
no title
Lossless
no title
Partitioning
no title | Device Names in Linux
cylinder translation
PC Disk Limitations
hard disks
Partition a Hard Disk | Partition a Hard Disk
hard drive
Partitioning Your Hard Drive | Background |
Background
root partition
Background
swap partition
Background
Linux partition
initializing
Initialize a Linux Partition |
Initialize a Linux Partition
PC BIOS
PC Disk Limitations
SCSI drives
PC Disk Limitations
servers
Recommended Partitioning Scheme
swap partition
initializing
Initialize and Activate a | Initialize
and Activate a
swap partitions
Recommended Partitioning Scheme | Recommended
Partitioning Scheme
partitions
mounting
Initialize a Linux Partition | Initialize a Linux
Partition | Mount a Previously-Initialized Partition
surface scanning
Initialize and Activate a
passwords
logging in
First Steps | First Steps
root password
setting
Set the Root Password
shadow passwords
Shadow Password Support
superuser
Working as Root
PATH
no title
paths
Files and Directories
PC BIOS
PC Disk Limitations
PCMCIA
no title
configuring
Configure PCMCIA Support
removing
Remove PCMCIA
Permissions
no title | Permissions | Permissions | Security
access
Mode
example session
Permissions in Practice | Permissions in Practice |
Permissions in Practice
file ownership
File Ownership | File Ownership
hard links
The Real Nature of
mode
Mode | Mode | Mode
PID
Processes
PID (Process Identification Number)
Processes
pipe operators
stdin, stdout, Pipelines, and
pipeline
Managing Processes with bash
pipelines
stdin, stdout, Pipelines, and
output
reversing
stdin, stdout, Pipelines, and
pipes
named pipes
Named Pipes (FIFOs)
plans
Managing Your Identity | Managing Your Identity
PPP
configuration
PPP | Preparation
wvdial
The Easy Way: wvdial | The Easy Way:
wvdial
primary partitions
PC Disk Limitations
printenv
Environment Variables | Environment Variables
Printing
no title
troubleshooting
Printing
proc filesystem
The proc Filesystem
process groups
Managing Processes with bash | Managing Processes with bash
Process Management
no title
Processes
no title | Processes
boot process
troubleshooting
Troubleshooting the Boot Process
comparing to programs
Processes
controlling
The Shell | The Shell
daemons
Processes
environments
Environment Variables
jobs
listing
Managing Processes with bash
starting
Managing Processes with bash
suspending
Managing Processes with bash | Managing
Processes with bash
terminating
Managing Processes with bash | Managing
Processes with bash
named pipes
Named Pipes (FIFOs)
PID (Process Identification Number)
Processes
redirection operators
stdin, stdout, Pipelines, and | stdin, stdout,
Pipelines, and
standard input
stdin, stdout, Pipelines, and
standard output
stdin, stdout, Pipelines, and
profiles
Planning Use of the | Planning Use of the
selecting
Select and Install Profiles | Select and Install
Profiles
programming
Software Development with Debian | Software Development with
Debian
programs
bash
aliases
Aliases
BIOS (Basic Input/Output System)
Booting the System
built-in
Where Commands Reside: The
cfdisk
Partition a Hard Disk | Partition a Hard Disk
comparing to processes
Processes
dbootstrap
Step-by-Step Installation
network configuration
Configure the Network
dselect
Select and Install Profiles | Introduction |
Introduction
Access screen
Access
multi-CD installation
Access
multi-NFS, multi-mount installation
Access
package states
Select | Select
packages, configuring
Configure
packages, installing
Install | Install
Update screen
Update | Select | Select | Select |
Select
executing
search path
Where Commands Reside: The | Where
Commands Reside: The
exiting
How to Read This
file managers
Introduction to X
functionality
What Is Debian?
gzip
File Compression with gzip | File Compression with
gzip
multitasking
A Multiuser, Multitasking Operating
packages
maintenance utilities
What a Package Maintenance | What a
Package Maintenance | dpkg | dselect
shell
The Shell | The Shell
software development
Software Development with Debian | Software
Development with Debian
tasks
Select and Install Profiles | Select and Install
Profiles
text editors
Text Editors | Text Editors
ae
Using ae
wvdial
PPP configuration
The Easy Way: wvdial | The Easy Way:
wvdial
X clients
X Clients | X Clients
Prompt, Changing
Environment Variables | Environment Variables
prompts
shell prompts
First Steps
proprietary software
comparing to commercial
What Is Free Software?
proxy servers
environment variables
setting
Access
PS1
Environment Variables | Environment Variables
pwd
Using Files: A Tutorial
pwd command
Using Files: A Tutorial | Using Files: A Tutorial
query process
Booting the System
questions
technical support
Personal Help | Tips for asking questions
quitting
ae (text editor)
Using ae
X windows system
Customizing Your X Startup | Customizing Your X
Startup
RAM
disk cache
Shutting Down
RAM (Random Access Memory)
installation requirements
Memory and Disk Space
reading
device files
Device Files
redirecting
output
stdin, stdout, Pipelines, and
pipelines
stdin, stdout, Pipelines, and
Redirection
no title
redirection operators
stdin, stdout, Pipelines, and
hard links
The Real Nature of
output
reversing
stdin, stdout, Pipelines, and
regular expressions
Regular Expressions | Regular Expressions | Regular Expressions
reinitializing
swap partition
Initialize and Activate a
removable disks
mounting filesystem
Removable Disks (Floppies, Zip
removing
directories
Using Files: A Tutorial
hard links
The Real Nature of
PCMCIA
Remove PCMCIA
symlinks
Symbolic Links | Symbolic Links
repartitioning
from Windows
Partitioning from DOS or | Lossless Repartitioning
hard drive
Partitioning Your Hard Drive | Background |
Background
requirements
installation
memory
Memory and Disk Space
restrictions
partitions
PC Disk Limitations
reversing
output
stdin, stdout, Pipelines, and
rm
Using Files: A Tutorial
root directory
Files and Directories | Files and Directories
root partition
Background
root password
setting
Set the Root Password
root user
Working as Root | Working as Root
see also superuser
Files Present and Their
saving
edited files (ae)
Using ae
scanning
hard disk
Initialize and Activate a
screen
display color
selecting
Select Color or Monochrome
screens
ae (text editor)
Using ae
dselect
Select
Select | Select | Select | Select |
Select
Update
Update
X windows system
windows manager
Introduction to X
scrolling
commands
Command History and Editing
SCSI drives
partitioning
PC Disk Limitations
partitions
Device Names in Linux
search path
Where Commands Reside: The | Where Commands Reside: The
security
backups, performing
Before You Start
passwords
logging in
First Steps | First Steps
shadow passwords
Shadow Password Support
permissions
Permissions | Permissions | Security
example session
Permissions in Practice | Permissions in
Practice | Permissions in Practice
file mode
Mode | Mode | Mode
file ownership
File Ownership | File Ownership
root password
setting
Set the Root Password
root user
Working as Root | Working as Root
Select screen (dselect)
Select | Select | Select | Select
selecting
color display
Select Color or Monochrome
fonts, xterm
Starting the X Environment
monochrome display
Select Color or Monochrome
packages
Select and Install Profiles | Select | Select |
Select
see also dselect
Introduction | Introduction
profiles
Select and Install Profiles | Select and Install
Profiles
X clients
Customizing Your X Startup | Customizing Your X
Startup
Server profile
Planning Use of the
servers
partitioning
Recommended Partitioning Scheme
proxy servers
environment variables, setting
Access
X server
killing
Leaving the X Environment
X servers
Introduction to X
clients
X Clients | X Clients
network transparency
Introduction to X
sh (Bourne shell)
The Shell
shadow passwords
Shadow Password Support
sharing
software
What Is Free Software? | What Is Free Software?
Shell
no title | The Shell | The Shell | no title
built-in programs
Where Commands Reside: The
filename expansion patterns
Filename Expansion
output
reversing
stdin, stdout, Pipelines, and
redirection operator
stdin, stdout, Pipelines, and | stdin, stdout,
Pipelines, and
search path
Where Commands Reside: The | Where Commands Reside:
The
shell commands
typing
First Steps
shell prompt
command history
Command History and Editing
command line
Command History and Editing | Command History and
Editing
shells
Bourne shell
The Shell
C shell
The Shell
command lines
job numbers, assigning
Managing Processes with bash
current working directory
Using Files: A Tutorial
environments
Environment Variables
jobs
suspending
Managing Processes with bash
pipelines
stdin, stdout, Pipelines, and
process groups
Managing Processes with bash | Managing Processes
with bash
redirection operators
hard links
The Real Nature of
variables
exporting
Environment Variables
xterms
Starting the X Environment
shortcut directories
Using Files: A Tutorial
shortcuts
aliases
Aliases
Shutdown
no title
shutting down
Shutting Down
sites
Web
Debian
What Is Free Software?
Free Software Foundation
What Is Free Software?
Multi Disk HOWTO
Recommended Partitioning Scheme
video cards, support for
Supported Hardware
smoke test
The Moment of Truth
Social Contract
What Is Free Software? | What Is Free Software? | What Is Free
Software?
sockets
Sockets
soft links
Symbolic Links
software
applications
What Is Debian?
development
Who Creates Debian?
free
developing
What Is Free Software?
Social Contract
What Is Free Software?
Free Software
What Is Free Software?
Open Source
What Is Free Software?
packages
mainenance utilities
What a Package Maintenance | dpkg |
dselect
sofware
development
Software Development with Debian | Software
Development with Debian
Source code
Viewing Text Files
comparing to binary executables
Viewing Text Files
spaces
typographical convention
Conventions
specifying
time zone
Configure the Base System
splitting
partitions
Lossless Repartitioning
Stallman, Richard M.
Why Software Should be Free
What Is Free Software?
standard error
stdin, stdout, Pipelines, and
standard input
stdin, stdout, Pipelines, and
standard output
stdin, stdout, Pipelines, and
starting
ae (text editor)
Using ae
jobs
Managing Processes with bash | Managing Processes
with bash | Managing Processes with bash
X windows system
Starting the X Environment
startup
boot process
BIOS
Booting the System
query process
Booting the System
X windows system
customizing
Customizing Your X Startup
states
packages (dselect)
Select | Select
status
jobs
displaying
Managing Processes with bash
stdin
no title
stdout
no title
structure
command line
The Command Line and
directories
Files and Directories
su command
Working as Root
subdirectories
filename expansion patterns
Filename Expansion | Filename Expansion
submitting
bug reports
Troubleshooting the Boot Process
superuser
Working as Root | Working as Root
home directory
Files Present and Their
superuser account
Set the Root Password
surface scanning
hard disks
Initialize and Activate a
suspending
jobs
Managing Processes with bash | Managing Processes
with bash
swap partition
Background
initializing
Initialize and Activate a | Initialize and Activate a
swap partitions
Recommended Partitioning Scheme | Recommended Partitioning Scheme
Linux swap partition
creating
Partition a Hard Disk | Partition a Hard
Disk
symlinks
Symbolic Links
comparing to hard links
Symbolic Links | Symbolic Links
removing
Symbolic Links
syntax
commands
The Command Line and | Describing the Command Line |
Describing the Command Line
file searches
Finding Files
system binaries
Files Present and Their
system clock
setting
Configure the Base System
system configuration
Debian Installation Steps | Choosing Your Installation Media
dbootstrap
Step-by-Step Installation
system-wide configuration
System-Wide Versus User-Specific Configuration
/etc directory
Files Present and Their
automatic filesystem mounting
/etc/fstab: Automating the Mount | /etc/fstab:
Automating the Mount
networking
Networking
Ethernet
Ethernet
PPP
PPP | Preparation | The Easy Way: wvdial
| The Easy Way: wvdial
packages
selecting
Select | Select | Select
permissions
file mode
Mode | Mode | Mode
file ownership
File Ownership
X windows system
customizing
Customizing Your X Startup
system-wide configuratoin
System-Wide Versus User-Specific Configuration
Taper
Backup Tools
taper (backup utility)
Backup Tools
tar
Backup Tools | no title
tar (tape archiver
tar
tasks
Select and Install Profiles | Select and Install Profiles
tcsh
The Shell
technical support
asking questions
Personal Help | Tips for asking questions
temporary files
Files Present and Their
Terminal
A Multiuser, Multitasking Operating
terminals
A Multiuser, Multitasking Operating
consoles
A Multiuser, Multitasking Operating
terminating
jobs
Managing Processes with bash | Managing Processes
with bash
testing
installation
smoke test
The Moment of Truth
text
bold face
typographical conventions
Conventions
fonts
xterm, selecting
Starting the X Environment
italicized
typographical conventions
Conventions
online manual
paging
Environment Variables
output
reversing
stdin, stdout, Pipelines, and
regular expressions
Regular Expressions | Regular Expressions | Regular
Expressions
wildcards
-
Filename Expansion
?
Filename Expansion
file searches
Finding Files
filename expansion patterns
Filename Expansion
text editors
Text Editors
ae
Using ae
text files
Working with Text Files | no title
viewing
Viewing Text Files
time zone
specifying
Configure the Base System
tools
backups
Backup Tools
GNU tar
tar
FIPS
Lossless Repartitioning | Lossless Repartitioning
troubleshooting
boot process
Troubleshooting the Boot Process
files
naming conventions
Working with Strangely-Named Files
printing
Printing
X windows system
Troubleshooting | X Problems
type
Where Commands Reside: The
typing
Bash commands
wildcards
Tab Completion
command line
Command History and Editing | Command History and
Editing
commands
aliases
Aliases
modifier keys
Conventions | Conventions
shell commands
First Steps
wildcards
?
Filename Expansion
filename expansion pattern
Filename Expansion
typographical conventions
Conventions | Conventions
bold face
Conventions
italics
Conventions
modifier keys
Conventions | Conventions
spaces
Conventions
uncompressing
files
File Compression with gzip
unmounting
CD-ROMs
Example: Mounting a CD-ROM
Update screen (dselect)
Update
user accounts
logging in
First Steps | First Steps
ordinary user
Create an Ordinary User | Create an Ordinary User
permission
Permissions | Permissions
permissions
example session
Permissions in Practice | Permissions in
Practice | Permissions in Practice
file ownership
File Ownership | File Ownership
mode
Mode | Mode | Mode
plans
Managing Your Identity | Managing Your Identity
root user
Working as Root | Working as Root
superuser
Set the Root Password
user-specific configuration
System-Wide Versus User-Specific Configuration | System-Wide
Versus User-Specific Configuration
dotfiles
System-Wide Versus User-Specific Configuration
utilities
archiving
Backup Tools
backup tools
Backup Tools
GNU tar
tar
dbootstrap
network configuration
Configure the Network
dselect
Select and Install Profiles | Introduction |
Introduction
Access screen
Access
multi-CD installation
Access
multi-NFS, multi-mount installation
Access
package states
Select | Select
packages, configuring
Configure
packages, installing
Install | Install
Update screen
Update | Select | Select | Select |
Select
file manager
Using a File Manager
FIPS
Lossless Repartitioning | Lossless Repartitioning
GNU documentation viewer
Using info | Using info
gzip
File Compression with gzip | File Compression with
gzip
package maintenance
What a Package Maintenance | What a Package
Maintenance
deselect
dselect
dpkg
dpkg
system binaries
Files Present and Their
tasks
Select and Install Profiles | Select and Install
Profiles
text editors
Text Editors | Text Editors
ae
Using ae
variables
Environment Variables
exporting
Environment Variables
shell
exporting
Environment Variables
vi (text editor)
Text Editors | Text Editors
video cards
support for
Supported Hardware
viewing
directory contents
Files Present and Their | Files Present and Their
file contents
Using Files: A Tutorial | Determining a File’s
Contents
files
filename expansion pattern
Filename Expansion
Info help system
Managing Processes with bash
job status
Managing Processes with bash
mounted filesystems
Example: Mounting a CD-ROM
online manual
Environment Variables
text files
Viewing Text Files
Virtual Consoles
no title | Virtual Consoles | Virtual Consoles
virtual devices
Device Files | /dev/null
web sites
Debian
What Is Free Software? | Personal Help | Personal
Help
Free Software Foundation
What Is Free Software?
Multi Disk HOWTO
Recommended Partitioning Scheme
Web sites:video cards, support for
Supported Hardware
whoami command
Working as Root
Why Software Should be Free (Stallman, Richard M.)
What Is Free Software?
wildcards
no title | Filename Expansion
*
Filename Expansion
?
Filename Expansion
Bash commands
Tab Completion
file searches
Finding Files
filename expansion pattens
Filename Expansion
regular expressions
Regular Expressions | Regular Expressions | Regular
Expressions
window managers
Introduction to X
Windows
partitioning
Partitioning from DOS or | Lossless Repartitioning |
Debian Installation Steps
Work profile
Planning Use of the
workstations
installation
Information You Will Need
write permission
Mode
writing
disk images to floppies
Creating Floppies from Disk | Creating Floppies from
Disk
to device files
Device Files
to named pipes
Named Pipes (FIFOs)
wvdial
PPP configuration
The Easy Way: wvdial | The Easy Way: wvdial
X clients
Introduction to X
network transparency
Introduction to X
selecting
Customizing Your X Startup | Customizing Your X
Startup
X servers
Introduction to X
X Window
The X Window System | Introduction to X
X windows system
clients
X Clients | X Clients
selecting
Customizing Your X Startup | Customizing
Your X Startup
customizing
Customizing Your X Startup
exiting
Leaving the X Environment | Customizing Your X
Startup | Customizing Your X Startup
mouse operation
The Mouse
network transparency
Introduction to X
starting
Starting the X Environment
troubleshooting
Troubleshooting | X Problems
xdm
Starting the X Environment
X, troubleshooting
no title
xcoral (text editor)
Text Editors
xdm (X Display Manager)
Starting the X Environment
xterm
font size, increasing
Starting the X Environment
fonts
selecting
Starting the X Environment
xterms
Starting the X Environment
Zip Disks
no title
About this document ...
Debian GNU/Linux: Guide to Installation and Usage
This document was generated using the LaTeX2HTML translator Version
2K.1beta (1.48)
Copyright (c) 1993, 1994, 1995, 1996, Nikos Drakos, Computer Based
Learning Unit, University of Leeds. Copyright (c) 1997, 1998, 1999,
Ross Moore, Mathematics Department, Macquarie University, Sydney.
The command line arguments were: latex2html -html_version 4.0,table
-split 0 -t ‘Debian GNU/Linux: Guide to Installation and Usage’
-toc_stars -local_icons -address ‘John Goerzen / Ossama Othman’
debian-tutorial.tex
The translation was initiated by John Goerzen on 2002-12-12
John Goerzen / Ossama Othman
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