Linux命令——yum
翻译自：20 Linux YUM (Yellowdog Updater, Modified) Commands for Package Management
前言
本篇文章将介绍如何使用RedHat开发的YUM（Yellowdog Updater Modified）工具，在Linux系统上安装，更新，删除，查找，管理软件包和软件仓库。
yum简介
yum，是Yellow dog Updater, Modified 的简称，是杜克大学为了提高RPM 软件包安装性而开发的一种软件包管理器。起初是由yellow dog 这一发行版的开发者Terra Soft 研发，用python 写成，那时还叫做yup(yellow dog updater)，后经杜克大学的Linux@Duke 开发团队进行改进，遂有此名。yum 的宗旨是自动化地升级，安装/移除rpm 包，收集rpm 包的相关信息，检查依赖性并自动提示用户解决。yum 的关键之处是要有可靠的repository，顾名思义，这是软件的仓库，它可以是http 或ftp 站点，也可以是本地软件池，但必须包含rpm 的header，header 包括了rpm 包的各种信息，包括描述，功能，提供的文件，依赖性等。正是收集了这些header 并加以分析，才能自动化地完成余下的任务。
yum 的理念是使用一个中心仓库(repository)管理一部分甚至一个distribution 的应用程序相互关系，根据计算出来的软件依赖关系进行相关的升级、安装、删除等等操作，减少了Linux 用户一直头痛的dependencies 的问题。这一点上，yum 和apt 相同。yum 可以同时配置多个资源库(Repository)，简洁的配置文件（/etc/yum.conf），自动解决增加或删除rpm 包时遇到的依赖性问题，保持与RPM 数据库的一致性。
yum命令使用示例
使用YUM安装包
要安装名为Firefox 14的软件包，只需运行以下命令，它将自动查找并安装Firefox所需的所有依赖项。
# yum install firefox Loaded plugins: fastestmirror Dependencies Resolved ================================================================================================ Package Arch Version Repository Size ================================================================================================ Updating: firefox i686 10.0.6-1.el6.centos updates 20 M Updating for dependencies: xulrunner i686 10.0.6-1.el6.centos updates 12 M Transaction Summary ================================================================================================ Install 0 Package(s) Upgrade 2 Package(s) Total download size: 32 M Is this ok [y/N]: y Downloading Packages: (1/2): firefox-10.0.6-1.el6.centos.i686.rpm | 20 MB 01:10 (2/2): xulrunner-10.0.6-1.el6.centos.i686.rpm | 12 MB 00:52 ------------------------------------------------------------------------------------------------ Total 63 kB/s | 32 MB 02:04 Updated: firefox.i686 0:10.0.6-1.el6.centos Dependency Updated: xulrunner.i686 0:10.0.6-1.el6.centos Complete!
在系统上安装任何软件包之前，上述命令将询问确认。如果要在不要求任何确认的情况下自动安装软件包，请使用选项-y，如下例所示。
yum -y install firefox
使用YUM删除包
删除包时，如果连依赖一起删除，只需要执行以下命令
yum remove firefox Loaded plugins: fastestmirror Setting up Remove Process Resolving Dependencies --> Running transaction check ---> Package firefox.i686 0:10.0.6-1.el6.centos set to be erased --> Finished Dependency Resolution Dependencies Resolved ==================================================================================================== Package Arch Version Repository Size ==================================================================================================== Removing: firefox i686 10.0.6-1.el6.centos @updates 23 M Transaction Summary ==================================================================================================== Remove 1 Package(s) Reinstall 0 Package(s) Downgrade 0 Package(s) Is this ok [y/N]: y Downloading Packages: Running rpm_check_debug Running Transaction Test Transaction Test Succeeded Running Transaction Erasing : firefox-10.0.6-1.el6.centos.i686 1/1 Removed: firefox.i686 0:10.0.6-1.el6.centos Complete!
同样，上面的命令会在删除包之前询问确认。要禁用确认提示，只需添加选项-y，如下所示。
yum -y remove firefox
yum remove有个弊端，例如yum remove -y vim，他只会匹配vim-xxx.rpm这个包，他的依赖包并不会被卸载。比如vim-minimal-7.4.160-4.el7.x86_64，必须单独写在才可以yum -y remove vim-minimal
使用YUM更新包
假设你有一个旧版本的MySQL，你希望将其更新为最新的稳定版本。只需运行以下命令，它将自动解决所有依赖项问题并安装它们。
# yum update mysql Loaded plugins: fastestmirror Dependencies Resolved ============================================================================================================ Package Arch Version Repository Size ============================================================================================================ Updating: vsftpd i386 2.0.5-24.el5_8.1 updates 144 k Transaction Summary ============================================================================================================ Install 0 Package(s) Upgrade 1 Package(s) Total size: 144 k Is this ok [y/N]: y Downloading Packages: Running rpm_check_debug Running Transaction Test Finished Transaction Test Transaction Test Succeeded Running Transaction Updating : vsftpd 1/2 Cleanup : vsftpd 2/2 Updated: vsftpd.i386 0:2.0.5-24.el5_8.1 Complete!
使用YUM列出包
使用list参数搜索具有名称的特定包。例如，要搜索名为openssh的包，使用命令
# yum list openssh Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirror.neu.edu.cn * epel: mirror.neu.edu.cn * extras: mirror.neu.edu.cn * rpmforge: mirror.nl.leaseweb.net * updates: mirror.nus.edu.sg Installed Packages openssh.i386 4.3p2-72.el5_6.3 installed Available Packages 4.3p2-82.el5
为了使您的搜索更准确，请使用其版本定义包名称，如果你知道的话。例如，搜索包的特定版本openssh-4.3p2
# yum list openssh-4.3p2
使用YUM搜索包
如果你不记得包的确切名称，请使用search参数搜索所有可用包以匹配你指定的包的名称。
# yum search vsftpd Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirror.neu.edu.cn * epel: mirror.neu.edu.cn * extras: mirror.neu.edu.cn * rpmforge: mirror.nl.leaseweb.net * updates: ftp.iitm.ac.in ============================== Matched: vsftpd ======================== ccze.i386 : A robust log colorizer pure-ftpd-selinux.i386 : SELinux support for Pure-FTPD vsftpd.i386 : vsftpd - Very Secure Ftp Daemon
使用YUM获取包的信息
假设您想在安装之前知道包的信息。要获取包的信息，只需发出以下命令。
# yum info firefox Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirror.neu.edu.cn * epel: mirror.neu.edu.cn * extras: mirror.neu.edu.cn * rpmforge: mirror.nl.leaseweb.net * updates: ftp.iitm.ac.in Available Packages Name : firefox Arch : i386 Version : 10.0.6 Release : 1.el5.centos Size : 20 M Repo : updates Summary : Mozilla Firefox Web browser URL : http://www.mozilla.org/projects/firefox/ License : MPLv1.1 or GPLv2+ or LGPLv2+ Description: Mozilla Firefox is an open-source web browser, designed for standards : compliance, performance and portability.
使用YUM列出所有可用包
要列出Yum数据库中的所有可用包，请使用以下命令。
# yum list | less
使用YUM列出所有已安装的软件包
要列出系统上所有已安装的软件包，只需发出以下命令，它将显示所有已安装的软件包。
# yum list installed | less
找出文件属于哪个软件包
provides参数用于查找特定文件所属的包。例如，如果您想知道包含/etc/httpd/conf/httpd.conf文件的包名称。
# yum provides /etc/httpd/conf/httpd.conf Loaded plugins: fastestmirror httpd-2.2.3-63.el5.centos.i386 : Apache HTTP Server Repo : base Matched from: Filename : /etc/httpd/conf/httpd.conf httpd-2.2.3-63.el5.centos.1.i386 : Apache HTTP Server Repo : updates Matched from: Filename : /etc/httpd/conf/httpd.conf httpd-2.2.3-65.el5.centos.i386 : Apache HTTP Server Repo : updates Matched from: Filename : /etc/httpd/conf/httpd.conf httpd-2.2.3-53.el5.centos.1.i386 : Apache HTTP Server Repo : installed Matched from: Other : Provides-match: /etc/httpd/conf/httpd.conf
使用whatprovides 效果是一样的
使用Yum检查可用更新
要查找系统上已安装的软件包有多少可用更新，请检查以下命令。
# yum check-update
使用Yum更新系统
如下命令将为系统安装所有最新补丁和安全更新。
# yum update
列出所有可用的Group Packages
在Linux中，若干个包可以捆绑到特定组。 你可以安装特定组（组中包的依赖会自动安装），而不是使用yum单个组内的软件包。 例如，要列出所有可用组，只需发出以下命令。
# yum grouplist Installed Groups: Administration Tools DNS Name Server Dialup Networking Support Editors Engineering and Scientific FTP Server Graphics Java Development Legacy Network Server Available Groups: Authoring and Publishing Base Beagle Cluster Storage Clustering Development Libraries Development Tools Eclipse Educational Software KDE (K Desktop Environment) KDE Software Development
安装Group Packages
要安装特定的软件包组，我们使用参数groupinstall。例如，要安装“MySQL数据库”，只需执行以下命令即可。
# yum groupinstall 'MySQL Database' Dependencies Resolved ================================================================================================= Package Arch Version Repository Size ================================================================================================= Updating: unixODBC i386 2.2.11-10.el5 base 290 k Installing for dependencies: unixODBC-libs i386 2.2.11-10.el5 base 551 k Transaction Summary ================================================================================================= Install 1 Package(s) Upgrade 1 Package(s) Total size: 841 k Is this ok [y/N]: y Downloading Packages: Running rpm_check_debug Running Transaction Test Finished Transaction Test Transaction Test Succeeded Running Transaction Installing : unixODBC-libs 1/3 Updating : unixODBC 2/3 Cleanup : unixODBC 3/3 Dependency Installed: unixODBC-libs.i386 0:2.2.11-10.el5 Updated: unixODBC.i386 0:2.2.11-10.el5 Complete!
更新Group Packages
使用参数groupupdate
# yum groupupdate 'DNS Name Server' Dependencies Resolved ================================================================================================================ Package Arch Version Repository Size ================================================================================================================ Updating: bind i386 30:9.3.6-20.P1.el5_8.2 updates 981 k bind-chroot i386 30:9.3.6-20.P1.el5_8.2 updates 47 k Updating for dependencies: bind-libs i386 30:9.3.6-20.P1.el5_8.2 updates 864 k bind-utils i386 30:9.3.6-20.P1.el5_8.2 updates 174 k Transaction Summary ================================================================================================================ Install 0 Package(s) Upgrade 4 Package(s) Total size: 2.0 M Is this ok [y/N]: y Downloading Packages: Running rpm_check_debug Running Transaction Test Finished Transaction Test Transaction Test Succeeded Running Transaction Updating : bind-libs 1/8 Updating : bind 2/8 Updating : bind-chroot 3/8 Updating : bind-utils 4/8 Cleanup : bind 5/8 Cleanup : bind-chroot 6/8 Cleanup : bind-utils 7/8 Cleanup : bind-libs 8/8 Updated: bind.i386 30:9.3.6-20.P1.el5_8.2 bind-chroot.i386 30:9.3.6-20.P1.el5_8.2 Dependency Updated: bind-libs.i386 30:9.3.6-20.P1.el5_8.2 bind-utils.i386 30:9.3.6-20.P1.el5_8.2 Complete!
移除Group Packages
使用参数groupremove
# yum groupremove 'DNS Name Server' Dependencies Resolved =========================================================================================================== Package Arch Version Repository Size =========================================================================================================== Removing: bind i386 30:9.3.6-20.P1.el5_8.2 installed 2.1 M bind-chroot i386 30:9.3.6-20.P1.el5_8.2 installed 0.0 Transaction Summary =========================================================================================================== Remove 2 Package(s) Reinstall 0 Package(s) Downgrade 0 Package(s) Is this ok [y/N]: y Downloading Packages: Running rpm_check_debug Running Transaction Test Finished Transaction Test Transaction Test Succeeded Running Transaction Erasing : bind 1/2 warning: /etc/sysconfig/named saved as /etc/sysconfig/named.rpmsave Erasing : bind-chroot 2/2 Removed: bind.i386 30:9.3.6-20.P1.el5_8.2 bind-chroot.i386 30:9.3.6-20.P1.el5_8.2 Complete!
列出已启用的Yum仓库
要列出系统中所有已启用的Yum存储库，请使用以下选项。
# yum repolist repo id repo name status base CentOS-5 - Base enabled: 2,725 epel Extra Packages for Enterprise Linux 5 - i386 enabled: 5,783 extras CentOS-5 - Extras enabled: 282 mod-pagespeed mod-pagespeed enabled: 1 rpmforge RHEL 5 - RPMforge.net - dag enabled: 11,290 updates CentOS-5 - Updates enabled: 743 repolist: 20,824
列出所有已启用和已禁用的Yum存储库
# yum repolist all repo id repo name status C5.0-base CentOS-5.0 - Base disabled C5.0-centosplus CentOS-5.0 - Plus disabled C5.0-extras CentOS-5.0 - Extras disabled base CentOS-5 - Base enabled: 2,725 epel Extra Packages for Enterprise Linux 5 - i386 enabled: 5,783 extras CentOS-5 - Extras enabled: 282 repolist: 20,824
从特定yum仓库安装包
要从特定的yum仓库（已启用或已禁用）安装特定软件包，必须在yum命令中使用-enablerepo选项。 例如，要安装PhpMyAdmin 3.5.2软件包，只需执行命令即可。
# yum --enablerepo=epel install phpmyadmin Dependencies Resolved ============================================================================================= Package Arch Version Repository Size ============================================================================================= Installing: phpMyAdmin noarch 3.5.1-1.el6 epel 4.2 M Transaction Summary ============================================================================================= Install 1 Package(s) Total download size: 4.2 M Installed size: 17 M Is this ok [y/N]: y Downloading Packages: phpMyAdmin-3.5.1-1.el6.noarch.rpm | 4.2 MB 00:25 Running rpm_check_debug Running Transaction Test Transaction Test Succeeded Running Transaction Installing : phpMyAdmin-3.5.1-1.el6.noarch 1/1 Verifying : phpMyAdmin-3.5.1-1.el6.noarch 1/1 Installed: phpMyAdmin.noarch 0:3.5.1-1.el6 Complete!
交互式yum shell
Yum提供自定义shell，可以在其中执行多个命令。
# yum shell Loaded plugins: fastestmirror Setting up Yum Shell > update httpd Loading mirror speeds from cached hostfile * base: mirrors.sin3.sg.voxel.net * epel: ftp.riken.jp * extras: mirrors.sin3.sg.voxel.net * updates: mirrors.sin3.sg.voxel.net Setting up Update Process >
清除Yum缓存
默认情况下，yum再/var/cache/yum及其子目录下保存已启用Yum仓库中的rpm包，要清除这些缓存下来的rpm包，需要定期运行以下命令来清理所有缓存并确保 没有什么不必要的空间正在使用。
# yum clean all
查看Yum历史
查看Yum命令的历史纪录
# yum history Loaded plugins: fastestmirror ID | Login user | Date and time | Action(s) | Altered ------------------------------------------------------------------------------- 10 | root | 2012-08-11 15:19 | Install | 3 9 | root | 2012-08-11 15:11 | Install | 1 8 | root | 2012-08-11 15:10 | Erase | 1 EE 7 | root | 2012-08-10 17:44 | Install | 1 6 | root | 2012-08-10 12:19 | Install | 2 5 | root | 2012-08-10 12:14 | Install | 3 4 | root | 2012-08-10 12:12 | I, U | 13 E< 3 | root | 2012-08-09 13:01 | Install | 1 > 2 | root | 2012-08-08 20:13 | I, U | 292 EE 1 | System | 2012-08-08 17:15 | Install | 560 history list
