1. 查看内核版本命令：

1) 方法1

[root@localhost ~]# cat /proc/version
Linux version 2.6.32-220.17.1.el6.x86_64 (mockbuild@c6b5.bsys.dev.centos.org) (gcc version 4.4.6 20110731 (Red Hat 4.4.6-3) (GCC) ) #1 SMP Wed May 16 00:01:37 BST 2012
You have new mail in /var/spool/mail/root

2) 方法2

[root@q1test01 ~]# uname -a
Linux q1test01 2.6.9-22.ELsmp #1 SMP Mon Sep 19 18:00:54 EDT 2005 x86_64 x86_64 x86_64 GNU/Linux

3)

[root@q1test01 ~]# uname -r
2.6.9-22.ELsmp

2. 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@localhost ~]# lsb_release -a
LSB Version: :core-4.0-amd64:core-4.0-noarch:graphics-4.0-amd64:graphics-4.0-noarch:printing-4.0-amd64:printing-4.0-noarch
Distributor ID: CentOS
Description: CentOS Linux release 6.0 (Final)
Release: 6.0
Codename: Final

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@localhost ~]# cat /etc/issue
CentOS Linux release 6.0 (Final)
Kernel \r on an \m

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

# cat /etc/redhat-release
Red Hat Enterprise Linux AS release 4 (Nahant Update 2)

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:

# rpm -q redhat-release
redhat-release-4AS-3

注: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

另:第3)、4)两种方法只对Redhat Linux有效

5)

[root@localhost ~]# file /bin/bash
/bin/bash: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.18, stripped

6)

[root@localhost ~]# file /bin/cat
/bin/cat: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.18, stripped