一。查看内核版本命令：

1） [root@SOR_SYS ~]# cat /proc/version
Linux version 2.6.18-238.el5 (mockbuild@x86-012.build.bos.redhat.com) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-50)) #1 SMP Sun Dec 19 14:22:44 EST 2010
[root@SOR_SYS ~]#

2）[root@SOR_SYS ~]# uname -r
2.6.18-238.el5
3）[root@SOR_SYS ~]# uname -a
Linux SOR_SYS.99bill.com 2.6.18-238.el5 #1 SMP Sun Dec 19 14:22:44 EST 2010 x86_64 x86_64 x86_64 GNU/Linux
[root@SOR_SYS ~]#

二。查看linux版本：

1) 登录到服务器执行 lsb_release -a ,即可列出所有版本信息,例如:

[root@SOR_SYS ~]# lsb_release -a
LSB Version:    :core-4.0-amd64:core-4.0-ia32:core-4.0-noarch:graphics-4.0-amd64:graphics-4.0-ia32:graphics-4.0-noarch:printing-4.0-amd64:printing-4.0-ia32:printing-4.0-noarch
Distributor ID: RedHatEnterpriseAS
Description:    Red Hat Enterprise Linux AS release 4 (Nahant Update 4)
Release:        4
Codename:       NahantUpdate4
[root@SOR_SYS ~]#

注:这个命令适用于所有的linux，包括Redhat、SuSE、Debian等发行版。

2) 登录到linux执行cat /etc/issue,例如如下:

[root@SOR_SYS ~]# cat /etc/issue
Red Hat Enterprise Linux Server release 5.6 (Tikanga)
Kernel \r on an \m

[root@SOR_SYS ~]#

3) 登录到linux执行cat /etc/redhat-release ,例如如下:

[root@SOR_SYS ~]# cat /etc/redhat-release
Red Hat Enterprise Linux AS release 4 (Nahant Update 4)
[root@SOR_SYS ~]#

注:这种方式下可以直接看到具体的版本号，比如 AS4 Update 1

4)登录到linux执行rpm -q redhat-release ,例如如下:

[root@SOR_SYS ~]# rpm -q redhat-release
redhat-release-5Server-5.6.0.3
[root@SOR_SYS ~]#

注:这种方式下可看到一个所谓的release号，比如上边的例子是5

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

另:第3)、4)两种方法只对Redhat Linux有效

5) [root@SOR_SYS ~]# file /bin/bash
/bin/bash: ELF 64-bit LSB executable, AMD x86-64, version 1 (SYSV), for GNU/Linux 2.6.9, dynamically linked (uses shared libs), for GNU/Linux 2.6.9, stripped
[root@SOR_SYS ~]#

6) [root@SOR_SYS ~]# file /bin/cat
/bin/cat: ELF 64-bit LSB executable, AMD x86-64, version 1 (SYSV), for GNU/Linux 2.6.9, dynamically linked (uses shared libs), for GNU/Linux 2.6.9, stripped
[root@SOR_SYS ~]#