服务器输出：[root@web4 ~]# rpm -q redhat-release
redhat-release-5Server-5.6.0.7
[root@web4 ~]#
这种方式下可看到一个所谓的release号，比如上边的例子是3
这个release号和实际的版本之间存在一定的对应关系，如下：
redhat-release-3AS-1 → Redhat Enterprise Linux AS 3
redhat-release-3AS-7.4 → Redhat Enterprise Linux AS 3 Update 4
redhat-release-4AS-2 → Redhat Enterprise Linux AS 4
redhat-release-4AS-2.4 → Redhat Enterprise Linux AS 4 Update 1
redhat-release-4AS-3 → Redhat Enterprise Linux AS 4 Update 2
redhat-release-4AS-4.1 → Redhat Enterprise Linux AS 4 Update 3
redhat-release-4AS-5.5 → Redhat Enterprise Linux AS 4 Update 4