1.查看Linux内核版本
	1.1 $ cat /proc/version
[heima01@heima01 ~]$ cat /proc/version
Linux version 2.6.32-573.el6.i686 ([email protected]) (gcc version 4.4.7 20120313 (Red Hat 4.4.7-16) (GCC) ) #1 SMP Thu Jul 23 12:37:35 UTC 2015

	1.2 $ uname -a
[heima01@heima01 ~]$ uname -a
Linux heima01 2.6.32-573.el6.i686 #1 SMP Thu Jul 23 12:37:35 UTC 2015 i686 i686 i386 GNU/Linux

	1.3 $ uname -r
[heima01@heima01 ~]$ uname -r
2.6.32-573.el6.i686

2.查看Linux发行版本
	2.1 $ lsb_release -a
[heima01@heima01 ~]$ lsb_release -a
LSB Version:	:base-4.0-ia32:base-4.0-noarch:core-4.0-ia32:core-4.0-noarch:graphics-4.0-ia32:graphics-4.0-noarch:printing-4.0-ia32:printing-4.0-noarch
Distributor ID:	CentOS
Description:	CentOS release 6.7 (Final)
Release:	6.7
Codename:	Final

	2.2 $ cat /etc/issue
[heima01@heima01 ~]$ cat /etc/issue
CentOS release 6.7 (Final)
Kernel \r on an \m

	2.3 $ cat /etc/redhat-release
		$ cat /etc/*release*
[heima01@heima01 ~]$ cat /etc/redhat-release
CentOS release 6.7 (Final)

[heima01@heima01 ~]$ cat /etc/*release*
CentOS release 6.7 (Final)
LSB_VERSION=base-4.0-ia32:base-4.0-noarch:core-4.0-ia32:core-4.0-noarch:graphics-4.0-ia32:graphics-4.0-noarch:printing-4.0-ia32:printing-4.0-noarch
cat: /etc/lsb-release.d: Is a directory
CentOS release 6.7 (Final)
CentOS release 6.7 (Final)
cpe:/o:centos:linux:6:GA

3.查看是否联网
	$ ping www.baidu.com
使用：
	因为使用yum工具安装软件可能需要网络。


	1.没有联网
[heima01@heima01 ~]$ ping www.baidu.com
PING www.a.shifen.com (182.61.200.6) 56(84) bytes of data.
^Z
[2]+  Stopped                 ping www.baidu.com
	2.已经联网
[root@instance-fjii60o3 ~]# ping www.baidu.com
PING www.a.shifen.com (220.181.38.150) 56(84) bytes of data.
64 bytes from 220.181.38.150 (220.181.38.150): icmp_seq=1 ttl=53 time=3.69 ms
64 bytes from 220.181.38.150 (220.181.38.150): icmp_seq=2 ttl=53 time=3.50 ms
64 bytes from 220.181.38.150 (220.181.38.150): icmp_seq=3 ttl=53 time=3.66 ms