https://www.cnblogs.com/qiu-freedom/articles/10799524.html
配置文件：/etc/yum.conf
下载安装：yum install gcc
更新：yum update
安装：yum install xxx
移除：yum remove xxx
清除已经安装过的档案（/var/cache/yum/）：yum clean all
搜寻：yum search xxx
列出所有档案：yum list
查询档案讯息：yum info xxx
