linux yum 命令
yum（ Yellow dog Updater, Modified）是一个在Fedora和RedHat以及SUSE中的Shell前端软件包管理器。
基於RPM包管理，能够从指定的服务器自动下载RPM包并且安装，可以自动处理依赖性关系，并且一次安装所有依赖的软体包，无须繁琐地一次次下载、安装。
yum提供了查找、安装、删除某一个、一组甚至全部软件包的命令，而且命令简洁而又好记。
yum 语法
yum [options] [command] [package ...]
- options：可选，选项包括-h（帮助），-y（当安装过程提示选择全部为"yes"），-q（不显示安装的过程）等等。
- command：要进行的操作。
- package操作的对象。
yum常用命令
- 1.列出所有可更新的软件清单命令：yum check-update
- 2.更新所有软件命令：yum update
- 3.仅安装指定的软件命令：yum install <package_name>
- 4.仅更新指定的软件命令：yum update <package_name>
- 5.列出所有可安裝的软件清单命令：yum list
- 6.删除软件包命令：yum remove <package_name>
- 7.查找软件包 命令：yum search <keyword>
- 8.清除缓存命令:
- yum clean packages: 清除缓存目录下的软件包
- yum clean headers: 清除缓存目录下的 headers
- yum clean oldheaders: 清除缓存目录下旧的 headers
- yum clean, yum clean all (= yum clean packages; yum clean oldheaders) :清除缓存目录下的软件包及旧的headers
国内 yum 源
网易（163）yum源是国内最好的yum源之一 ，无论是速度还是软件版本，都非常的不错。
将yum源设置为163 yum，可以提升软件包安装和更新的速度，同时避免一些常见软件版本无法找到。
[root@localhost ~]# cd /etc/yum.repos.d [root@localhost yum.repos.d]# ll total 24 -rw-r--r--. 1 root root 1991 Mar 28 2017 CentOS-Base.repo -rw-r--r--. 1 root root 647 Mar 28 2017 CentOS-Debuginfo.repo -rw-r--r--. 1 root root 289 Mar 28 2017 CentOS-fasttrack.repo -rw-r--r--. 1 root root 630 Mar 28 2017 CentOS-Media.repo -rw-r--r--. 1 root root 7989 Mar 28 2017 CentOS-Vault.repo [root@localhost yum.repos.d]# mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup [root@localhost yum.repos.d]# ll total 24 -rw-r--r--. 1 root root 1991 Mar 28 2017 CentOS-Base.repo.backup -rw-r--r--. 1 root root 647 Mar 28 2017 CentOS-Debuginfo.repo -rw-r--r--. 1 root root 289 Mar 28 2017 CentOS-fasttrack.repo -rw-r--r--. 1 root root 630 Mar 28 2017 CentOS-Media.repo -rw-r--r--. 1 root root 7989 Mar 28 2017 CentOS-Vault.repo [root@localhost yum.repos.d]# wget http://mirrors.163.com/.help/CentOS6-Base-163.repo --2019-12-04 01:17:41-- http://mirrors.163.com/.help/CentOS6-Base-163.repo Resolving mirrors.163.com... 59.111.0.251 Connecting to mirrors.163.com|59.111.0.251|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 2006 (2.0K) [application/octet-stream] Saving to: “CentOS6-Base-163.repo” 100%[=================================================================================================================>] 2,006 --.-K/s in 0s 2019-12-04 01:17:42 (349 MB/s) - “CentOS6-Base-163.repo” saved [2006/2006] [root@localhost yum.repos.d]# mv CentOS6-Base-163.repo CentOS-Base.repo [root@localhost bin]# yum clean all Loaded plugins: fastestmirror, refresh-packagekit, security Cleaning repos: base extras updates Cleaning up Everything Cleaning up list of fastest mirrors [root@localhost bin]# yum makecache Loaded plugins: fastestmirror, refresh-packagekit, security Determining fastest mirrors base | 3.7 kB 00:00 base/group_gz | 242 kB 00:00 base/filelists_db | 6.4 MB 00:02 base/primary_db | 4.7 MB 00:01 base/other_db | 2.8 MB 00:00 extras | 3.4 kB 00:00 extras/filelists_db | 24 kB 00:00 extras/prestodelta | 2.2 kB 00:00 extras/primary_db | 29 kB 00:00 extras/other_db | 14 kB 00:00 updates | 3.4 kB 00:00 updates/filelists_db | 5.2 MB 00:06 updates/prestodelta | 258 kB 00:00 updates/primary_db | 7.5 MB 00:02 updates/other_db | 330 kB 00:00 Metadata Cache Created [root@localhost bin]#
实例 1
安装 pam-devel
[root@localhost bin]# yum install pam-devel Loaded plugins: fastestmirror, refresh-packagekit, security Setting up Install Process Loading mirror speeds from cached hostfile Resolving Dependencies --> Running transaction check ---> Package pam-devel.x86_64 0:1.1.1-24.el6 will be installed --> Finished Dependency Resolution Dependencies Resolved =========================================================================================================================================================== Package Arch Version Repository Size =========================================================================================================================================================== Installing: pam-devel x86_64 1.1.1-24.el6 base 205 k Transaction Summary =========================================================================================================================================================== Install 1 Package(s) Total download size: 205 k Installed size: 547 k Is this ok [y/N]: y Downloading Packages: pam-devel-1.1.1-24.el6.x86_64.rpm | 205 kB 00:00 Running rpm_check_debug Running Transaction Test Transaction Test Succeeded Running Transaction Installing : pam-devel-1.1.1-24.el6.x86_64 1/1 Verifying : pam-devel-1.1.1-24.el6.x86_64 1/1 Installed: pam-devel.x86_64 0:1.1.1-24.el6 Complete! [root@localhost bin]#
实例 2
移除 pam-devel
[root@localhost bin]# yum remove pam-devel Loaded plugins: fastestmirror, refresh-packagekit, security Setting up Remove Process Resolving Dependencies --> Running transaction check ---> Package pam-devel.x86_64 0:1.1.1-24.el6 will be erased --> Finished Dependency Resolution Dependencies Resolved =========================================================================================================================================================== Package Arch Version Repository Size =========================================================================================================================================================== Removing: pam-devel x86_64 1.1.1-24.el6 @base 547 k Transaction Summary =========================================================================================================================================================== Remove 1 Package(s) Installed size: 547 k Is this ok [y/N]: y Downloading Packages: Running rpm_check_debug Running Transaction Test Transaction Test Succeeded Running Transaction Erasing : pam-devel-1.1.1-24.el6.x86_64 1/1 Verifying : pam-devel-1.1.1-24.el6.x86_64 1/1 Removed: pam-devel.x86_64 0:1.1.1-24.el6 Complete! [root@localhost bin]#
实例 3
利用 yum 的功能，找出以 yum 为开头的软件名称有哪些？
[root@localhost bin]# yum list yum* Loaded plugins: fastestmirror, refresh-packagekit, security Loading mirror speeds from cached hostfile Installed Packages yum.noarch 3.2.29-81.el6.centos @anaconda-CentOS-201703281317.x86_64/6.9 Available Packages yum.noarch 3.2.29-81.el6.centos.0.1 updates [root@localhost bin]#