Arch Linux

Not to be confused with Ark Linux.

Arch Linux

Arch linux logo
Developer	Aaron Griffin & team
OS family	Unix-like
Working state	Current
Source model	Open source
Initial release	March 2002
Latest release	(Rolling release) / Installation CD 2009.02
Repository	git.archlinux.org
Update method	Pacman
Package manager	Pacman
Platforms	IA-32, x86-64, PPC
Kernel type	Monolithic
Default user interface	BASH
License	GNU GPL & others
Official website	www.archlinux.org

Arch Linux (or Arch) is a Linux distribution intended to be lightweight and simple. The design approach of the development team focuses on "simplicity", elegance, code correctness and minimalism. "Simplicity", according to Arch, is defined as "...without unnecessary additions, modifications, or complications.." and is defined from a developer standpoint, rather than a user standpoint.

Inspired by CRUX, another minimalist distribution, Judd Vinet started Arch Linux in March 2002. Vinet led the project until 1 October 2007, when he stepped down due to lack of time, transferring control of the project to Aaron Griffin. The Arch in Arch Linux is pronounced [ɑːrtʃ] in rhotic English accents or [aːtʃ] in non-rhotic accents (as in archer or parchment).

Design and principles

Arch is largely based around binary packages. Packages are targeted for IA-32 and x86-64 microprocessors to assist performance on modern hardware. A ports/ebuild-like system is also provided for automated source compilation, known as the ABS (Arch Build System).

The Arch focus on simplicity and economy for developers means, among other things, that the main effort in assisting the user is not expended in crafting GUI configuration tools - the package manager, for example, does not have an official graphical front-end - but making well-annotated configuration files and extensive use of shell scripts. This has earned it a reputation as a distribution for "intermediate and advanced Linux users who aren't afraid of the command line" .

Relying on complex tools to manage and build your system is going to hurt the end users. [...] "If you try to hide the complexity of the system, you'll end up with a more complex system". Layers of abstraction that serve to hide internals are never a good thing. Instead, the internals should be designed in a way such that they NEED no hiding.

— Aaron Griffin, http://phraktured.net/arch-way.html

init framework

Arch uses a BSD-style init framework, a tradeoff of flexibility for simplicity. It also includes and permits use of System V runlevels and the inittab file, but there is little differentiation between runlevels. This is due to the fact that the modules and daemons loaded at startup are arranged very simply as arrays in the central configuration file, /etc/rc.conf, as opposed to System V's system of a directory for each runlevel containing a numbered symbolic link for each daemon. There is also the ability to start processes asynchronously, which neither the original BSD init nor the original Sys V init have. See init for more detail on the differences between the two systems.

Installation

The Arch Linux website supplies both CD (ISO) and USB (IMG) images for ease of use. In keeping with the Arch commitment to the KISS principle, the Arch Linux installer is simply a shell script using dialog for user interaction (~ 10–15 minutes). The slim default install provides only a base GNU/Linux environment, including the GNU toolchain, the Linux kernel, a few extra modules and libraries, and the bash shell. Further system customization and expansion (adding additional software such as a window manager, desktop environment, etc.) must be done manually, installing packages downloaded from online repositories. Arch is therefore generally considered relatively involved to install, in comparison to other operating systems.

Package management

Pacman

Pacman Package Manager

Main article: Pacman (package manager)

All packages are managed using the Pacman package manager. Pacman handles package installation, upgrades, removal and downgrades, and features automatic dependency resolution. The packages for Arch Linux are obtained from the Arch Linux package tree and are optimized for either i686 or x86-64 architectures. Arch Linux is primarily based on binary packages in the tar.gz format for installation speed.

Repositories

Currently there are four official repositories:

• core, which contains all the packages needed to set up a base system
• extra, which holds packages not required for the base system, including desktop environments and programs
• testing, a special repository, with packages that are candidates for the core or extra repositories.
• community, which contains packages built and voted on by the community; includes packages that have sufficient votes and have been adopted by a "trusted user".

The unstable repository was dropped in July 2008 and most of the packages moved to other repositories. In addition to the official repositories there are a number of unofficial user repositories (AUR).

ABS

ABS is a ports-like source packaging system which compiles source tarballs into binary packages, that are installed via Pacman. ABS provides a directory tree of shell scripts called PKGBUILDS, which enable any and all official Arch packages to be customized and compiled. Rebuilding the entire system using modified compiler flags is also supported by ABS. The ABS makepkg tool can be used to create custom .pkg.tar.gz packages from third-party sources. The resulting packages are also cleanly installable and trackable via Pacman.

AUR

In addition to the repositories, the Arch Linux User-community Repository (AUR) provides user-made PKGBUILD scripts for packages not included in the repositories. The PKGBUILD scripts simplify building from source by explicitly listing and checking for dependencies and configuring the install to match the Arch architecture. The scripts are available for download from http://aur.archlinux.org. AUR helper programs can further streamline the downloading and building process. However, such tools that search, download and run PKGBUILD scripts automatically will never be included in the official repositories because of potential security risks.

The AUR provides the community with packages that are not included in the repositories. Reasons include:

• License issues. Software that cannot be redistributed, but is free to use, can be included in the AUR since all that is hosted by the Arch Linux web site is a shell script that downloads the actual software from elsewhere. Examples include proprietary freeware such as Google Earth and RealPlayer.
• Modified official packages. The AUR also contains many variations on the official packaging as well as beta versions of software that is contained within the repositories as stable releases.

PKGBUILDS for any software can be contributed by ordinary users and any PKGBUILD that is not confined to the AUR for policy reasons can be voted into the community repositories.

Versions

"Rolling releases"

Similarly to Gentoo, and unlike other major distributions such as Fedora, , Debian, Ubuntu, and others, Arch Linux does not schedule releases for specific dates but uses a "rolling release" system, with new packages provided daily. Its package management permits users to keep systems up-to-date easily. Rather than encouraging users to move between discrete releases, Arch Linux releases are simply snapshots of the current set of packages, sometimes with revised installation software. Therefore it makes no difference from which release Arch gets installed if updates are installed afterwards. As a result, Arch never needs to be reinstalled to provide new updates or features.

From version 2009.02 the goal is to bring coordinated releases following the rhythm of kernel releases, in order to provide optimal hardware support, this means a new release every 3 or four months. For those desktop computers and laptops that have 64-bit compatible i.e. AMD64/x86-64 processors; it is recommended to use the Arch Linux version compiled for 64-bit.

As of February 2009, the latest image is 2009.02, dated 16 February 2009.

Release history

Color	Meaning
Yellow	Old release
Green	Current release
Blue	Future release

Version	Code name	Date	Notes
0.1	Homer	2002-03-11	First release built From Scratch.
0.2	Vega	2002-04-17
0.3	Firefly	2002-08-07
0.4	Dragon	2002-12-18
0.5	Nova	2003-06-21	Support for PAM, LVM, GRUB.
0.6	Widget	2004-03-01	Support for JFS and XFS added.
0.7	Wombat	2005-01-24
0.8	Voodoo	2007-03-31
2007.05	Duke	2007-05-17	Pacman v3
2007.08	Don't Panic	2007-08-05
2008.06	Overlord	2008-06-24	Availability of USB disk images.
2009.02	2009.02	2009-02-16	Inclusion of AIF (Arch Linux Installation Framework). ext4 support added.

Live Arch environments

The official Arch install media presents the user with a basic Arch system complete with standard CLI tools from which the installer can be run. For the user who wishes to have access to a full GUI without or before installing, live CDs have been developed:

• Archie - A complete live Arch environment, using KDE and Xfce.
• DeLi Linux – Based on Slackware, but uses Pacman package manager.
• FaunOS – Uses the KDE desktop.
• Frugalware – Based on Slackware, but uses Pacman package manager.
• Arch Live – The archiso-live version uses the Xfce and LXDE desktops by default.
• Chakra – Uses KDEmod desktop by default, Qt graphical installer & package manager based on Pacman.

See also

List of Linux distributions

External links

• Arch Linux Website
• Arch Linux Documentation
• Arch Linux at DistroWatch
• A collection of Arch Linux books for free download
• Interview with Judd Vinet about Arch Linux
• The Big Arch Linux Interview, an interview with most of the Arch Linux developer team
• A Review of ArchLinux