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Arch Linux

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Arch Linux
Arch Linux logo
DeveloperAaron Griffin and team[1]
OS familyUnix-like
Working stateCurrent
Source modelFree and open source software
Initial releaseMarch 11, 2002; 22 years ago (2002-03-11)
Latest release(Rolling release) / Installation medium 2014.06.01
Repository
Marketing targetGeneral purpose
Update methodPacman
Package managerPacman
Platformsi686, x86-64
Kernel typeMonolithic (Linux)
UserlandGNU
Default
user interface		Bash
LicenseVarious[2]
Official websitewww.archlinux.org

Arch Linux (or Arch /ˈɑːrtʃ/)[3] is a Linux-based operating system for i686 and x86-64 computers.[4] It is composed predominantly of free and open source software,[5] and supports community involvement.[6]

The design approach of the development team focuses on elegance, code correctness, minimalism, and simplicity, and expects the user to be willing to make some effort to understand the system's operation.[7] A package manager written specifically for Arch Linux, pacman, is used to install, remove and update software packages.

Arch Linux uses a rolling release model, such that a regular system update is all that is needed to obtain the latest Arch software; the installation images released by the Arch team are simply up-to-date snapshots of the main system components.[8]

History

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.[9]

Design and principles

Arch is largely based around binary packages. Packages are targeted for i686 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 Arch Build System.

Arch Linux focuses on simplicity of design, meaning that the main focus involves creating an environment that is straight-forward and relatively easy for the user to understand directly, rather than providing polished point-and-click style management tools — the package manager, for example, does not have an official graphical front-end. This is largely achieved by encouraging the use of succinctly commented, clean configuration files that are arranged for quick access and editing.[7] This has earned it a reputation as a distribution for "intermediate and advanced Linux users who aren't afraid of the command line".[10]

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[11]

Installation

The Arch Linux website supplies ISO images that can be run from CD or USB. A simple command line script (pacstrap) is used to install the base system.[12] The installation of additional packages, which are not part of the base system (for example, desktop environments), can be done with either pacstrap, or pacman after booting (or chrooting) into the new installation.

An alternative to using CD or USB images for installation is to use the static version of the package manager Pacman, from within another Linux based operating system.[13] The user can mount their newly formatted drive partition, and use pacstrap (or Pacman with the appropriate command-line switch) to install base and additional packages with the mountpoint of the destination device as the root for its operations. This method is useful when installing Arch Linux onto USB flash drives, or onto a temporarily mounted device which belongs to another system.

Either way, further actions need to be taken before the new system is ready for use, most notably installing a bootloader, creating an initramfs, and configuring the new system.

Package management

Pacman

To facilitate regular package changes, pacman was developed by Judd Vinet to provide Arch with its own package manager able to track dependencies.[14]

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 compiled for either i686 or x86-64 architectures. It uses binary packages in the tar.xz format,[15] with .pkg placed before this to indicate that it is a Pacman package (giving .pkg.tar.xz).[16]

Repositories

Currently, the following basic official binary repositories exist:[17]

  • 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
  • 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".
  • multilib, a centralized repository for x86_64 users to more readily support 32-bit applications in a 64-bit environment.

In addition, there also exist testing repositories that include binary package candidates for other repositories. Currently, the following testing repositories exist:

  • testing, with packages for core and extra.
  • community-testing, with packages for community.
  • multilib-testing, with packages for multilib.

The staging and community-staging repositories are used for some rebuilds to avoid broken packages in testing.

The unstable repository was dropped in July 2008 and most of the packages moved to other repositories.[18] In addition to the official repositories, there are a number of unofficial user repositories.

The most well-known unofficial repository is the Arch User Repository, or AUR, hosted on the Arch Linux site. However, the AUR does not host binary packages, instead hosting a collection of build scripts known as PKGBUILDs.

Repository security

Until pacman version 4.0.0[19] Arch Linux's package manager lacked support for signed packages.[20] Packages and metadata were not verified for authenticity by pacman during the download-install process. Without package authentication checking, tampered-with or malicious repository mirrors can compromise the integrity of a system.[21] Pacman 4 allowed verification of the package database and packages, but it was disabled by default. In November 2011 package signing became mandatory for new package builds, and as of 21 March 2012 every official package is signed.[22]

In June 2012, package signing verification became official and is now enabled by default in the installation process.[23][24]

Arch Build System (ABS)

The Arch Build System (ABS) is a ports-like source packaging system that compiles source tarballs into binary packages, which are installed via Pacman.[25] The Arch Build System provides a directory tree of shell scripts, called PKGBUILDs, that enable any and all official Arch packages to be customized and compiled. Rebuilding the entire system using modified compiler flags is also supported by the Arch Build System. The Arch Build System makepkg tool can be used to create custom pkg.tar.xz packages from third-party sources. The resulting packages are also installable and trackable via Pacman.[26]

Arch User Repository (AUR)

In addition to the repositories, the Arch User 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 the Arch Linux web site.[27] Arch User Repository 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.[28][specify]

Users can create packages compatible with pacman using the Arch Build System and custom PKGBUILD scripts.[29] This functionality has helped support the Arch User Repository, which consists of user contributed packages to supplement the official repositories.[30]

The Arch User Repository 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 Arch User Repository 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 Arch User Repository also contains many variations on the official packaging as well as beta versions of software that is contained within the repositories as stable releases.
  • Rarity of the software. Some new or rarely used programs have not been added to the official repositories (yet).

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

Versions

Rolling releases

Similar to Gentoo, and unlike other major distributions such as Ubuntu and Fedora, Arch Linux does not schedule releases for specific dates but uses a "rolling release" system, with new packages provided daily. Its package management allows users to keep systems up-to-date easily.[31] 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 usually makes no difference from which release Arch gets installed if updates are installed afterwards, but occasionally manual interventions are required for certain updates, with instructions posted on the news section of the Arch Linux website. In fact, some members of the Arch forums take pride in showing the age of the installation.[32]

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 4 months.[33] Monthly updated ISOs are released on every first week of a month. As of 10 April 2014, the latest image is 2014.04.01 released on 1 April 2014.[34]

Other kernels

There are some projects porting the Arch Linux ideas and tools to other kernels: ArchBSD[35] and Archhurd,[36] based on FreeBSD and the GNU Hurd kernel respectively.

Other architectures

There is Arch Linux ARM[37] which aims to port Arch Linux to ARM-based devices, including the Raspberry Pi.

See also

References

  1. ^ Aaron Griffin, Lead Developer at ArchLinux
  2. ^ Licenses, wiki.archlinux.org, 2011-09-24, retrieved 2011-10-02
  3. ^ Pronnounciation [sic] of our beloved distribution's name, Osdir.com, 2005-08-24, retrieved 2009-10-19
  4. ^ "Arch Linux - About". Archlinux.org. Retrieved 2011-09-27.
  5. ^ "Explaining Why We Don't Endorse Other Systems". Gnu.org. Retrieved 2011-09-28.
  6. ^ "Arch Linux". Distrowatch.com. Retrieved 2011-09-28.
  7. ^ a b "The Arch Way". Wiki.archlinux.org. 2009-10-09. Retrieved 2013-03-18.
  8. ^ "Rolling with Arch Linux". lwn.net. 2010-03-10. Retrieved 2011-09-30.
  9. ^ "Arch Leadership". Arch Linux Forums. Bbs.archlinux.org. Retrieved 2009-10-19.
  10. ^ "Archlinux". Wiki.polishlinux.org. Retrieved 2009-10-19.
  11. ^ Archway, phraktured.net, 2007-11-09, retrieved 2012-01-22
  12. ^ "News: Install media 2012.07.15 released". archlinux.org. 2012-07-22. Retrieved 2012-08-23.
  13. ^ "Install From Existing Linux". Wiki.archlinux.org. 2009-11-21. Retrieved 2009-12-05.
  14. ^ "Arch Linux: Why It Rocks". osnews.com. 2005-03-21. Retrieved 2011-09-30.
  15. ^ Pierre Schmitz (2010-03-23). "Switching to xz compression for new packages". Archlinux.org. Archived from the original on 28 March 2010. Retrieved 2010-03-23. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  16. ^ "pacman - ArchWiki". Wiki.archlinux.org. Retrieved 2014-03-25.
  17. ^ Official Repositories, wiki.archlinux.org, retrieved 2012-11-23
  18. ^ "Arch Linux Newsletter 08-04-2008". Archlinux.org. 2008-08-04. Retrieved 2009-10-19.
  19. ^ Pacman NEWS file as of 4.0.0, retrieved 14 October 2011
  20. ^ "FS#5331 - Signed packages". Retrieved 2011-08-07.
  21. ^ "Attacks on Package Managers". cs.arizona.edu. 2008-07-10. Archived from the original on 5 September 2010. Retrieved 2010-09-14. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  22. ^ Allan McRae (2011-12-17). "Pacman Package Signing – 4: Arch Linux". Retrieved 2012-02-29.
  23. ^ "Having pacman verify packages". Gaetan Bisson. 2012-06-04. Retrieved 2012-06-04.
  24. ^ "Install media 2012.07.15 released". archlinux.org. 2012-07-22. Retrieved 2012-08-13.
  25. ^ "Arch Build System". wiki.archlinux.org. Retrieved 2009-10-19.
  26. ^ "Makepkg". wiki.archlinux.org. Retrieved 2013-02-15.
  27. ^ "AUR (en) - Home". Aur.archlinux.org. Retrieved 2014-02-05.
  28. ^ "Arch Linux: Popular KISS distro – Interview – Part II". Hardware.no. Retrieved 2009-10-19.
  29. ^ "Using the Arch Build System". library.linode.com. 2011-09-08. Retrieved 2011-09-30.
  30. ^ "Arch Linux". linuxdistroreview.com. 2011-03-08. Retrieved 2011-09-30.
  31. ^ "Arch Linux Review". DVD-Guides.com. Retrieved 2009-10-19.
  32. ^ "Age of your linux installation?". Arch Linux Forums. Bbs.archlinux.org. Retrieved 2014-03-24.
  33. ^ Aaron Griffin (2009-02-16), 2009.02 ISO Release
  34. ^ "Latest installation medium", Arch Linux – Download, 2014-04-01
  35. ^ "Arch BSD". Arch BSD. Retrieved 2014-03-25.
  36. ^ "Arch Hurd". Arch Hurd. Retrieved 2014-03-25.
  37. ^ "Arch Linux ARM". Arch Linux ARM. Retrieved 2014-03-25.
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