Chapter 1. Preface

Table of Contents

1.1. Disclaimer
1.2. What is Debian
1.3. About this document
1.3.1. Guiding rules
1.3.2. Prerequisites
1.3.3. Conventions
1.3.4. The popcon
1.3.5. The package size
1.3.6. Bug reports
1.4. Some quotes for new users

This Debian Reference (version 2) (2009-01-17 17:51:59 UTC) is intended to provide a broad overview of Debian system administration as a post-installation user guide.

The target reader is someone who is willing to learn shell scripts but who is not ready to read all the C sources to figure out how the GNU/Linux system works.

1.1. Disclaimer

All warranties are disclaimed. All trademarks are property of their respective trademark owners.

The Debian system itself is a moving target. This makes its documentation difficult to be current and correct. Although the current unstable version of Debian system was used as the basis for writing this, some contents may be already outdated by the time you read this.

Please treat this document as the secondary reference. This document does not replace any authoritative guides. The author and contributors do not take responsibility for consequences of errors, omissions or ambiguity in this document.

1.2. What is Debian

The Debian Project is an association of individuals who have made common cause to create a free operating system. It's distribution is characterized by:

Free Software pieces in Debian come from GNU, Linux, BSD, X, Berkeley DB, ISC, Apache, Ghostscript, Common Unix Printing System , Samba, GNOME, KDE, Mozilla, OpenOffice.org, Vim, TeX, LaTeX, DocBook, Perl, Python, Tcl, Java, Ruby, PHP, MySQL and many more independent free software projects. Debian integrates this diversity of Free Software into one system.

1.3. About this document

1.3.1. Guiding rules

Following guiding rules were followed while compiling this document:

  • don't explain in details what is well documented elsewhere (in the judgment of the author)

  • Provide overview and skip corner cases (Big Picture)

  • Keep It Short and Simple. (KISS)

  • Focus on non-GUI tools and consoles. (Use shell examples)

  • Do not reinvent the wheel. (Use pointers to the existing references)

  • Be objective. (Use popcon etc.)

I tried to elucidate hierarchical aspects and lower levels of the system.

1.3.2. Prerequisites

You are required to seek help from (in approximate order of importance, starting with the most important sources):

[Note] Note

For detailed documentation, you may need to install the corresponding documentation package named with "-doc" as its suffix.

1.3.3. Conventions

This document refers to some command names followed by the number in parenthesis , such as bash(1). This means that you are encouraged to obtain information from the manpage by typing the following on the shell command prompt:

$ man 1 bash 

This document provides information through the following simplified presentation style with bash(1) shell command examples and bullets:

# <command in root account>
$ <command in user account>
  • <description of action>

These shell prompts distinguish account used and correspond to PS1='\$' and PS2=' ' environment variables. These values are chosen for the sake of readability of this document and are not typical on actual installed system.

[Note] Note

See the meaning of the PS1 and PS2 environment variables in the manpage of bash(1) command.

1.3.4. The popcon

The popcon data was presented as the objective measure for the popularity of each package. It was downloaded on 2009-01-18 and contains the total submission of 79097 reports over 91823 binary packages and 20 architectures.

[Note] Note

Please note that the amd64 unstable archive contains only 24396 packages currently. The popcon data contains reports from many old system installations.

The popcon number preceded with "V:" for "votes" is calculated by 100 * (the popcon submissions for the package executed recently on the PC)/(the total popcon submissions).

The popcon number preceded with "I:" for "installs" is calculated by 100 * (the popcon submissions for the package installed on the PC)/(the total popcon submissions).

[Note] Note

The popcon figures should not be considered as absolute measures of the importance of packages. There are many factors which can skew statistics. For example, some system participating popcon may have mounted directories such as /bin with "noatime" option for system performance improvement and effectively disabled "vote" from such system.

1.3.5. The package size

The package size data was also presented as the objective measure for each package. It is based on the "Installed-Size:" reported by "apt-cache show " command (currently on amd64 architecture for the unstable release). The reported size is in KB (unit for 1024 bytes).

[Note] Note

A package with a small numerical package size may indicate that the package in the unstable release has a dummy package which installs other packages with significant contents by the dependency. The dummy package enables a smooth transition or split of the package.

1.3.6. Bug reports

Please file bug reports on "debian-reference" package using reportbug(1) if you find any issues. For simple spell errors and grammar corrections, you may alternatively edit the source text available as Debian Reference wiki page at http://wiki.debian.org/DebianReference and tell me to update the document.

1.4. Some quotes for new users

Here are some interesting quotes from the Debian mailing list which may help enlighten new users:

  • "This is Unix. It gives you enough rope to hang yourself." --- Miquel van Smoorenburg <miquels at cistron.nl>

  • "Unix IS user friendly... It's just selective about who its friends are." --- Tollef Fog Heen <tollef at add.no>