Arch has an easy-to-use binary package management system (PACMAN), which allows you to upgrade the whole system with one command. Pacman is written in C language, which is light, simple and fast. Arch also provides an Arch Build system similar to ports. Through this system, you can easily build and install software packages from the source code, and you can complete synchronization with one command. You can even rebuild the whole system with one command. The official source code of Arch provides thousands of high-quality i686/x86-64 binary packages to meet your software requirements. In addition, in order to encourage the community to develop and contribute code, Arch also provides the Arch User Repository, which contains thousands of PKGBUILD scripts maintained by users, and cooperates with the makepkg tool, from compilation to packaging in one go. Users can also easily build and maintain their own customized software sources. As soon as the software package is upgraded, a pacman command can upgrade the whole system. The time required depends on the usage time of the system. This command will synchronize the non-local software repositories and upgrade the software packages of the system: # pacman -Syu Warning: Due to the rolling upgrade feature of Arch, upgrading the system will produce unpredictable results. Therefore, unless you have free time and are ready to deal with unexpected problems, please upgrade cautiously. The second pacman package manager is a highlight of Arch Linux. It combines a simple binary package format with an easy-to-use build system (see makepkg and ABS). Pacman can easily manage whether the software package comes from the official Arch library or is created by users themselves. Pacman updates the system by synchronizing the software package list with the main server, which makes the maintenance of security-oriented system administrators easy. This server/client mode can download/install the software package with one command and install the necessary dependent packages at the same time. Pacman is written in c language and packaged into pkg.tar.xz format. 3. The configuration file for configuring pacman is located at/etc/pacman.conf ... manpacman.conf. You can view more information about the configuration file. General Options General options are in the Options section. For information and usage, please read the man manual or view the default pacman.conf 1 Do not upgrade the package. If for some reason, the user does not want to upgrade the software package, you can add the following: IgnorePkg = software package name. Multiple packages can be separated by spaces or glob mode. If you only want to skip one upgrade, you can use the-ignore option. Ignored packages can be upgraded through pacman -S 2. Just like software packages, you can also skip the installation of some folders without upgrading a software package group: IgnoreGroup = gnome3, and you can put them in NoExtract. For example, if you don't want to install the systemd unit file: noextract = usr/lib/systemd/system/* 4, the software warehouse defined in this part is referenced in /etc/pacman.conf, which can be set directly or included in other files. All official software warehouses use the same /etc/pacman.d/mirrorlist file containing' $repo', so only one list needs to be maintained. In the following example, the official software repository is used to set up an example of mirroring using mirrorlist. #[testing]# SIG level = package required # Include =/etc/pacman . d/mirror list[core]SIG level = PackageRequiredInclude =/etc/pacman . d/ mirror list[extra]SIG level = PackageRequiredInclude =/etc/pacman . d/mirror list #[community-testing]# SIG level = package required # Include =/etc/ Pacman. d/mirror list # If you plan to run 3 # [mulib-testing] # siglevel = package equired # include =/etc/pacman.d/mirrorlist # [mulib] # Siglevel = packagequired # include =/etc/pacman.d/mirrorlist # For an example of customizing a depot, please refer to the pacman man page to learn how to create a depot. # [custom] # siglevel = optional trustall # server = file://home/custompkgs Warning: Be careful when using the [testing] warehouse. The warehouse is being actively developed, which may cause some software packages to fail to run. It is suggested that users who use [testing] subscribe to the arch-dev-public mailing list to get the latest information. Security of software packages pacman 4 supports software package signing. The statement SIG level = Required Database Optional will enable global signature verification, but it will be overwritten by the siglevel line of each depot. See pacman-key for details. For other examples of using pacman, please read man pacman. The following is just a small demonstration of what can be done. Install packages Install the specified packages Install or upgrade a single package or a series of packages (including dependent packages). Use the following commands: # Pacman-s package _ name1package _ name2 ... Install multiple packages with regular expressions (see Pacman prompt and this post): # pacman-s $ (pacman-ssq package _ regex) Sometimes in different software warehouses, a package has multiple versions (such as [extra] and [testing]. You can choose an installation: # pacman-ssextra/package _ name installation package group Some packages belong to a package group that can be installed at the same time. For example, running the following command # pacman -S gnome will prompt the user to select the package to install in gnome. Some package groups contain a large number of software packages, and sometimes users only need a few of them. In addition to entering serial numbers one by one, pacman also supports selecting or excluding software packages within a certain interval: enter a selection (default is all): 1-10/5 This will select software packages with serial numbers from1to10 and 15. And enter a selection (default = all): 5-8 2 All packages except serial numbers 5 to 8 and 2 will be selected. To see which packages belong to the gnome group, run: # pacman -Sg gnome or visit/repo/example.pkg.tar.xz. Partial upgrade is not supported. Arch Linux is a rolling distribution, and new library versions will be pushed to the source code continuously. Developers and trusted users will rebuild all software packages in the source code as needed. If there are locally installed versions (such as AUR packages), they need to be recompiled when their dependencies upgrade soname. In other words, partial upgrade is not supported. Do not use pacman -Sy package or equivalent command before pacman-s package, such as pacman -Sy. Please update the source code and upgrade before installing the software package. Similarly, please pay special attention to the use of IgnorePkg/IgnoreGroup. If a partial upgrade is made, the binary package will be damaged because the link library cannot be found. Don't fix it by simple symbolic links. Libraries upgrade soname because they are no longer forward compatible. As long as pacman can run, these problems can be fixed by using the updated source code of pacman -Syu. General Precautions Warning: Use the-force switch carefully. Improper use will cause big problems. Please use it only when Arch news requests it. Pacman comes with many utilities to make the system more convenient to use. All tool functions can be viewed through the-help switch. Run: $ pacman-qlpacman | awk-f "[/]"'/\/usr \/bin/{print $5}' See https://wiki.archlinux.org/index.php/pacman _ (%E7% AE% 80% E4%).