思路：卸载Red Hat Enterprise Linux 6.4自带yum，然后下载CentOS的yum，安装后修改配置文件
1、首先到http://mirrors.163.com/centos下载软件包
x86 地址：http://mirrors.163.com/centos/6/os/i386/Packages/
x86_64 地址：http://mirrors.163.com/centos/6/os/x86_64/Packages/
必要下载的软件包有（以64位系统为例）：
a python-iniparse-0.3.1-2.1.el6.noarch.rpm
b yum-3.2.29-40.el6.centos.noarch.rpm
c yum-metadata-parser-1.1.2-16.el6.x86_64.rpm
d yum-plugin-fastestmirror-1.1.30-14.el6.noarch.rpm
下载命令：
wget http://mirrors.163.com/centos/6/os/x86_64/Packages/python-iniparse-0.3.1-2.1.el6.noarch.rpm
wget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-metadata-parser-1.1.2-16.el6.x86_64.rpm
wget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-3.2.29-40.el6.centos.noarch.rpm
wget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.30-14.el6.noarch.rpm
[注] :版本不一定要最新的
2、卸载RedHat自带的yum
rpm -qa | grep yum | xargs rpm -e --nodeps
注：a、xargs是一条Unix和类Unix操作系统的常用命令。它的作用是将参数列表转换成小块分段传递给其他命令，以避免参数列表过长的问题
b、--nodeps 强制卸载,不管依赖性
3、安装下载的centos的yum包：
rpm -ivh python-iniparse-0.3.1-2.1.el6.noarch.rpm
rpm -ivh yum-metadata-parser-1.1.2-16.el6.x86_64.rpm
rpm -ivh yum-3.2.29-40.el6.centos.noarch.rpm yum-plugin-fastestmirror-1.1.30-14.el6.noarch.rpm
[注] :最后2个需要一起安装，否则会出现依赖性错误
4、到http://mirrors.163.com的 centos帮助文档 中下载CentOS6-Base-163.repo文件，存放到/etc/yum.repo.d中
wget http://mirrors.163.com/.help/CentOS6-Base-163.repo
5、编辑CentOS6-Base-163.repo文件，将其中的$releasever更改为centos的版本号
下面是修改好的：
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-6 - Base - 163.com
baseurl=http://mirrors.163.com/centos/6/os/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=os
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#released updates
[updates]
name=CentOS-6 - Updates - 163.com
baseurl=http://mirrors.163.com/centos/6/updates/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=updates
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#additional packages that may be useful
[extras]
name=CentOS-6 - Extras - 163.com
baseurl=http://mirrors.163.com/centos/6/extras/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=extras
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-6 - Plus - 163.com
baseurl=http://mirrors.163.com/centos/6/centosplus/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=centosplus
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#contrib - packages by Centos Users
[contrib]
name=CentOS-6 - Contrib - 163.com
baseurl=http://mirrors.163.com/centos/6/contrib/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=contrib
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
6、yum clean all 清除原有缓存
7、yum makecache 获取yum列表
出现下面提示，表示yum更改完成：
Metadata Cache Created
Red Hat Enterprise 6.4配置CentOS 6.4软件源另一篇：
1. 用su 命令切换到root
2. 删除rhel6.4自带的yum，命令如下：
rpm -aq|grep yum|xargs rpm -e --nodeps
3. 下载CentOS 6.4的yum，命令如下：
wget http://mirrors.163.com/centos/6.4/os/x86_64/Packages/python-iniparse-0.3.1-2.1.el6.noarch.rpm
wget http://mirrors.163.com/centos/6.4/os/x86_64/Packages/yum-3.2.29-40.el6.centos.noarch.rpm
wget http://mirrors.163.com/centos/6.4/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.30-14.el6.noarch.rpm
wget http://mirrors.163.com/centos/6.4/os/x86_64/Packages/yum-metadata-parser-1.1.2-16.el6.x86_64.rpm
4.安装yum
rpm -ivh python-iniparse-0.3.1-2.1.el6.noarch.rpm
rpm -ivh yum-metadata-parser-1.1.2-16.el6.x86_64.rpm
rpm -ivh
yum-3.2.29-40.el6.centos.noarch.rpm yum-plugin-fastestmirror-1.1.30-14.el6.noarch.rpm
5.配置repo文件
新建CentOS-Base.repo文件，内容为：
[base]
name=CentOS-6 - Base
repo=os
baseurl=http://mirrors.163.com/centos/6.4/os/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#released updates
[update]
name=CentOS-6 - Updates
baseurl=http://mirrors.163.com/centos/6.4/updates/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#packages used/produced in the build but not released
#[addons]
#name=CentOS-6 - Addons
#baseurl=http://mirrors.163.com/centos/6.4/addons/$basearch/
#gpgcheck=1
#gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#additional packages that may be useful
[extras]
name=CentOS-6 - Extras
baseurl=http://mirrors.163.com/centos/6.4/extras/$basearch/
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-6 - Plus
baseurl=http://mirrors.163.com/centos/6.4/centosplus/$basearch/
gpgcheck=1
enabled=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#contrib - packages by Centos Users
[contrib]
name=CentOS-6 - Contrib
baseurl=http://mirrors.163.com/centos/6.4/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
保存后将CentOS-Base.repo移到/etc/yum.repos.d/ 里面，命令如下：
mv ./CentOS-Base.repo /etc/yum.repos.d/
6.清除yum缓存
clean yum all
7.试试能不能用 yum install gcc-c++-4.4.7-3.el6
来源：Linux社区
