有以下命令可以查看：
rpm -q centos-release
# lsb_release -a
LSB Version: :core-3.1-ia32:core-3.1-noarch:graphics-3.1-ia32:graphics-3.1-noarch
Distributor ID: CentOS
Description: CentOS release 5.4 (Final)
Release: 5.4
Codename: Final
这个命令适用于所有的linux，包括Redhat、SuSE、Debian、Centos等发行版。
root@MyMail ~ # uname
Linux
root@MyMail ~ # uname -r
2.6.18-164.el5
[root@localhost ~]# uname -a
Linux localhost.localdomain 2.6.18-194.el5 #1 SMP Fri Apr 2 14:58:35 EDT 2010 i686 i686 i386 GNU/Linux
以下二种方法适用于RedHat,CentOS
root@MyMail ~ # cat /etc/redhat-release
CentOS release 5.4 (Final)
登录到linux执行rpm -q redhat-release
#rpm -q redhat-release
或CentOS
root@MyMail ~ # rpm -q centos-release
centos-release-5-4.el5.centos.1
当前centos 版本与redhat对应的版本的命令
# cat /proc/version
Linux version 2.6.9-78.ELsmp (mockbuild@builder16.centos.org) (gcc version 3.4.6 20060404 (Red Hat 3.4.6-10)) #1 SMP Fri Jul 25 00:04:28 EDT 2008