linux下使用YUM安装GCC、gcc-c++

         在安装服务器的时候图快捷没有装一些系统软件，结果后来需要使用C++编译环境，由于系统本身没有C编译环境，所以不能下载源码进行安装，只能下载rpm文件进行安装，可是在使用rpm安装时，有许多的依赖安装包，又考虑到系统可以联网所以便使用了YUM安装GCC。

        先说下YUM的原理吧：CentOS先将发布的软件放置到YUM服务器内，然后分析这些软件的依赖属性，将软件内的记录信息写下来。然后将这些信息分析后记录成软件相关性的清单列表。当客户端有软件安装的需求时，客户端主机会主动想网络上面的yum服务器请求下载要安装的软件和相关的依赖性属性的软件。

     说了这么多直接上这两句高端大气上档次的语句吧：

 yum -y install gcc
 yum -y install gcc-c++

下图显示安装的过程：

[root@localhost ~]# yum -y install gcc
Loaded plugins: fastestmirror, rhnplugin, security
Repository base is listed more than once in the configuration
Repository updates is listed more than once in the configuration
Repository extras is listed more than once in the configuration
Repository centosplus is listed more than once in the configuration
Repository contrib is listed more than once in the configuration
This system is not registered with RHN.
RHN support will be disabled.
Loading mirror speeds from cached hostfile
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package gcc.i386 0:4.1.2-51.el5 set to be updated
--> Processing Dependency: glibc-devel >= 2.2.90-12 for package: gcc
--> Running transaction check
---> Package glibc-devel.i386 0:2.5-65 set to be updated
--> Processing Dependency: glibc-headers = 2.5-65 for package: glibc-devel
--> Processing Dependency: glibc-headers for package: glibc-devel
--> Running transaction check
---> Package glibc-headers.i386 0:2.5-65 set to be updated
--> Processing Dependency: kernel-headers >= 2.2.1 for package: glibc-headers
--> Processing Dependency: kernel-headers for package: glibc-headers
--> Running transaction check
---> Package kernel-headers.i386 0:2.6.18-274.3.1.el5 set to be updated
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================
 Package              Arch       Version                    Repository     Size
================================================================================
Installing:
 gcc                  i386       4.1.2-51.el5               base          5.2 M
Installing for dependencies:
 glibc-devel          i386       2.5-65                     base          2.0 M
 glibc-headers        i386       2.5-65                     base          604 k
 kernel-headers       i386       2.6.18-274.3.1.el5         updates       1.2 M

Transaction Summary
================================================================================
Install       4 Package(s)
Upgrade       0 Package(s)

Total download size: 9.1 M
Downloading Packages:
(1/4): glibc-headers-2.5-65.i386.rpm                     | 604 kB     00:06     
(2/4): kernel-headers-2.6.18-274.3.1.el5.i386.rpm        | 1.2 MB     00:14     
(3/4): glibc-devel-2.5-65.i386.rpm                       | 2.0 MB     00:11     
(4/4): gcc-4.1.2-51.el5.i386.rpm                         | 5.2 MB     00:27     
--------------------------------------------------------------------------------
Total                                           149 kB/s | 9.1 MB     01:02     
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing     : kernel-headers                                           1/4 
  Installing     : glibc-headers                                            2/4 
  Installing     : glibc-devel                                              3/4 
  Installing     : gcc                                                      4/4 

Installed:
  gcc.i386 0:4.1.2-51.el5                                                       

Dependency Installed:
  glibc-devel.i386 0:2.5-65                     glibc-headers.i386 0:2.5-65     
  kernel-headers.i386 0:2.6.18-274.3.1.el5     

Complete!
[root@localhost ~]#