1、查询软件包；
面对成千上万的软件，我们可能无从下手，有时也不知道它的文件名；这时就要用到查询；我们可以用 yum list 来列出yum升级源上的包有文件；然后我们再来查看 info
有以下几个组合可以用；比如；
[root@localhost beinan]# yum list |more 加上一个管道 |，然后 more 一下，就能把所有的包分页显示出来。然后按一下空格键就能看下一页了。在显示的软件列表中，会有软件名称、版本、是否安装等；仔细的看一下吧。熟悉了就好了。也没有什么难的。 [root@localhost beinan]# yum list |more
Setting up repositories
Reading repository metadata in from local files
Installed Packages
4Suite.i386 1.0-8.b1 installed
Canna.i386 3.7p3-13 installed
Canna-devel.i386 3.7p3-13 installed 如果想知道软件的详细信息，可能得用上info参数了。比如： 用法：
[root@localhost beinan]# yum info 软件名 比如： [root@localhost beinan]# yum info bmp-mp3
Setting up repositories
updates-released 100% |=========================| 951 B 00:00
extras 100% |=========================| 1.1 kB 00:00
base 100% |=========================| 1.1 kB 00:00
freshrpms 100% |=========================| 951 B 00:00
Reading repository metadata in from local files
Installed Packages
Name : bmp-mp3
Arch : i386
Version: 0.9.7
Release: 1.2.fc4
Size : 234 k
Repo : freshrpms
Summary: MP3 playback plugin for the Beep Media Player
Description:
This package contains an MP3 playback plugin for BMP (Beep Media Player),
a media player that uses a skinned user interface based on Winamp 2.x skins,
and is based on ("forked off") XMMS. 在上面的例子中，如果Repo : freshrpms是这样的，表示您的系统没有安装这个软件，如果显示的是：Repo : installed，表示已经安装了。 查询软件包，也可以再加参数 grep ，比如我们想查询升级源上是否有内核的新版本，则我们可以用下面的命令查询；当然您也可以用 [root@localhost beinan]# yum search kernel |more ，也就是yum --help提供的参数，也是一样的；
[root@localhost beinan]# yum info kernel.i686
[root@localhost beinan]# yum info kernel.i686
Setting up repositories
updates-released 100% |=========================| 951 B 00:00
extras 100% |=========================| 1.1 kB 00:00
base 100% |=========================| 1.1 kB 00:00
freshrpms 100% |=========================| 951 B 00:00
Reading repository metadata in from local files
Installed Packages
Name : kernel
Arch : i686
Version: 2.6.11
Release: 1.1369_FC4
Size : 37 M
Repo : installed
Summary: Linux 内核(Linux 操作系统的核心)。
Description:
kernel 软件包包含 Linux 内核 (vmlinuz)，Red Hat Linux
操作系统的核心。内核处理操作系统的基本功能：
分配内存、处理分配、设备的输入和输出等等。
Available Packages
Name : kernel
Arch : i686
Version: 2.6.12
Release: 1.1398_FC4
Size : 14 M
Repo : updates-released
Summary: The Linux kernel (the core of the Linux operating system)
Description:
The kernel package contains the Linux kernel (vmlinuz), the core of any
Linux operating system. The kernel handles the basic functions
of the operating system: memory allocation, process allocation, device
input and output, etc. 通过上面的信息，我们可以看到 2.6.11的是已经安装了，因为已经显示的是Repo : installed ，下面还有一个Version: 2.6.12 ，告诉我们是Repo : updates-released，看来这个是升级用的了。 所以是否升级就看我们的了。 [root@localhost beinan]# yum update kernel 升级内核全景如下： [root@localhost beinan]# yum update kernel
Setting up Upgrade Process
Setting up repositories
updates-released 100% |=========================| 951 B 00:00
extras 100% |=========================| 1.1 kB 00:00
base 100% |=========================| 1.1 kB 00:00
freshrpms 100% |=========================| 951 B 00:00
Reading repository metadata in from local files
Resolving Dependencies
--> Populating transaction set with selected packages. Please wait.
---> Downloading header for kernel to pack into transaction set.
kernel-2.6.12-1.1398_FC4. 100% |=========================| 174 kB 00:18
---> Package kernel.i686 0:2.6.12-1.1398_FC4 set to be installed
--> Running transaction check
Dependencies Resolved
=============================================================================
Package Arch Version Repository Size
=============================================================================
Installing:
kernel i686 2.6.12-1.1398_FC4 updates-released 14 M
Transaction Summary
=============================================================================
Install 1 Package(s)
Update 0 Package(s)
Remove 0 Package(s)
Total download size: 14 M
Is this ok [y/N]: 是不是升级，只需要在 Is this ok [y/N]:行的后面输入y或者N；y是yes，就是点头同意的意思；N就是摇头No的意思。 对于软件包的查询，还有，比如：
[root@localhost beinan]# yum list available 列出所有升级源上的包；
[root@localhost beinan]# yum list updates 列出所有升级源上的可以更新包；
[root@localhost beinan]# yum list installed 列出已经安装的包； yum 的命令支持通配符； 比如； [root@localhost beinan]# yum list mp* |more
Setting up repositories
Reading repository metadata in from local files
Installed Packages
mpage.i386 2.5.4-5 installed
Available Packages
mpc.i386 0.11.2-3 extras
mpeg2dec.i386 0.4.0-5b.2.fc4 freshrpms
mpeg2dec-devel.i386 0.4.0-5b.2.fc4 freshrpms
mpg321.i386 0.2.10-6.2.fc4 freshrpms
mplayer.i386 1.0-0.16.pre7.2.fc4 freshrpms
mplayer-docs.i386 1.0-0.16.pre7.2.fc4 freshrpms
mplayer-fonts.noarch 1.1-3.fc freshrpms
mplayer-skins.noarch 1.7-1.fc freshrpms
[root@localhost beinan]# 2.安装和升级软件包；
安装和升级分别是 install 和 update 参数；比如；
[root@localhost beinan]# yum update firefox 这样我们就可以升级 firefox了。 [root@localhost beinan]# yum update firefox
Setting up Update Process
Setting up repositories
updates-released 100% |=========================| 951 B 00:00
extras 100% |=========================| 1.1 kB 00:00
base 100% |=========================| 1.1 kB 00:03
freshrpms 100% |=========================| 951 B 00:02
Reading repository metadata in from local files
Resolving Dependencies
--> Populating transaction set with selected packages. Please wait.
---> Package firefox.i386 0:1.0.6-1.1.fc4 set to be updated
--> Running transaction check
Dependencies Resolved
=============================================================================
Package Arch Version Repository Size
=============================================================================
Updating:
firefox i386 1.0.6-1.1.fc4 updates-released 18 M
Transaction Summary
=============================================================================
Install 0 Package(s)
Update 1 Package(s)
Remove 0 Package(s)
Total download size: 18 M
Is this ok [y/N]: 如果不加参数的 update 会是什么呢？？ [root@localhost beinan]# yum update 试着运行一下看看？会好长时间，对系统进行全面更新，我们要进行y和N了。
3.移除软件包要用到remove参数；比如；
在论坛中有好多，有兴趣的弟兄自己找找看吧；但也不要忘记了自救；呵。。。。 [root@localhost beinan]# yum --help
Usage: yum [options]
Options:
-c [config file] - specify the config file to use
-e [error level] - set the error logging level
-d [debug level] - set the debugging level
-y - answer yes to all questions
-R [time in minutes] - set the max amount of time to randomly run in
-C run from cache only - do not update the cache
--installroot=[path] - set the install root (default '/')
--version - output the version of yum
--exclude=package to exclude
--disablerepo=repository id to disable (overrides config file)
--enablerepo=repository id to enable (overrides config file)
-h, --help - this screen 还有更厉害的帮助；
