本脚本适用Centos 6 和Centos 7

1.脚本

#!/bin/bash
version=`cat /etc/redhat-release|sed -r 's/.* ([0-9]+)\..*/\1/'`

if [ $version == 6 ];then
echo "系统版本6是:"$version

elif [ $version == 7 ];then
echo "系统版本7是:"$version

fi

2.示例：