@http://graybull.is-programmer.com/posts/37702.htmlRedhat Enterprise Linux 6.1 x86_64 使用官方yum源是需要收费的，本文将讲解如何使用免费的CentOS的yum源来安装/更新软件。分成以下几步：卸载已有的yum下载CentOS的yum包安装CentOS的yum包更新repo文件清除旧缓存使用测试1.卸载已有的yum查看已安装的yum包有哪些：#rpm -aq|grep yum卸载已安装的yum包：#rpm -aq|grep yum | xargs rpm -e --nodeps从这里发现xargs犇死了。2.下载CentOS的yum包从163镜像（http://mirrors.163.com/centos/6/os/x86_64/Packages/）下载以下几个包（不同时间下载包的版本或许不同）： python-iniparse-0.3.1-2.1.el6.noarch.rpmyum-3.2.29-30.el6.centos.noarch.rpmyum-metadata-parser-1.1.2-16.el6.x86_64.rpmyum-plugin-fastestmirror-1.1.30-14.el6.noarch.rpm 下载方法：可以直接从镜像网站下载；或者使用wget下载：wget http://mirrors.163.com/centos/6/os/x86_64/Packages/python-iniparse-0.3.1-2.1.el6.noarch.rpmwget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-3.2.29-30.el6.centos.noarch.rpmwget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-metadata-parser-1.1.2-16.el6.x86_64.rpmwget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.30-14.el6.noarch.rpm  3.安装CentOS的yum包#rpm -ivh *.rpm4.更新repo文件进入配置目录：#cd /etc/yum.repos.d如果目录中没有rhel-debuginfo.repo文件，则新建一个，修改内容为： [base]name=CentOS-$releasever - Basebaseurl=http://mirrors.163.com/centos/6/os/$basearch/gpgcheck=1gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-6#released updates[updates]name=CentOS-$releasever - Updatesbaseurl=http://mirrors.163.com/centos/6/updates/$basearch/gpgcheck=1gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-6#packages used/produced in the build but not released#[addons]#name=CentOS-$releasever - Addons#baseurl=http://mirrors.163.com/centos/$releasever/addons/$basearch/#gpgcheck=1#gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-6#additional packages that may be useful[extras]name=CentOS-$releasever - Extrasbaseurl=http://mirrors.163.com/centos/6/extras/$basearch/gpgcheck=1gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-6#additional packages that extend functionality of existing packages[centosplus]name=CentOS-$releasever - Plusbaseurl=http://mirrors.163.com/centos/6/centosplus/$basearch/gpgcheck=1enabled=0 5.清除旧缓存#yum clean all6.使用测试列举yum包：#yum list安装g++g++为何物？g++可以用来编译C++代码啦。linux默认安装gcc，但往往没有安装g++。首先查找g++：#yum list gcc-c++返回的信息中包含有：gcc-c++.x86_64 所以，安装g++的命令为：#yum install gcc-c++.x86_64安装过程中，如果提示需要安装某些依赖的包，那么根据指示安装即可。若要验证是否成功安装g++，查看版本吧：#g++ -v