//查看系统构架
[root@localhost ~]# uname
Linux

//显示主机名/内核/硬件平台等全部信息
[root@localhost ~]# uname -a
Linux localhost.localdomain 2.6.32-504.el6.x86_64 #1 SMP Wed Oct 15 04:27:16 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

//查看具体小版本
[root@localhost ~]# cat /etc/redhat-release 
CentOS release 6.6 (Final)

//查看主机名称
[root@localhost ~]# hostname
localhost.localdomain

//设置主机名
[root@localhost ~]# hostname final.free.com
[root@localhost ~]# hostname 
final.free.com

//查看第一块网卡信息
[root@localhost ~]# ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:0C:29:CC:3D:CF  
          inet addr:192.168.20.129  Bcast:192.168.20.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fecc:3dcf/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2698 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2592 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:241180 (235.5 KiB)  TX bytes:162138 (158.3 KiB)
          
//更改ip地址
[root@final ~]# ifconfig eth0 192.168.100.100
[root@final ~]# ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:0C:29:CC:3D:CF  
          inet addr:192.168.100.100  Bcast:192.168.100.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fecc:3dcf/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:3087 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2834 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:274372 (267.9 KiB)  TX bytes:192382 (187.8 KiB)
          
//查看cpu信息
[root@final ~]# cat /proc/cpuinfo 
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 60
model name	: Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz
...

//查看内存信息
[root@final ~]# cat /proc/meminfo 
MemTotal:        1906492 kB
MemFree:         1645616 kB
...

//显示当前目录
[root@final ~]# pwd
/root

//打开目录
[root@final ~]# cd /etc/pki/CA/private/
[root@final private]# pwd
/etc/pki/CA/private

//返回上一个目录
[root@final private]# cd ..
[root@final CA]# pwd
/etc/pki/CA

//返回上两个目录
[root@final CA]# cd ../../
[root@final etc]# pwd
/etc

//查看当前目录信息
[root@final ~]# ls

//查看当前目录详细信息
[root@final ~]# ls -l

//保存内存缓存信息
[root@final etc]# sync

//服务器还有15分钟关闭维护
[root@final etc]# shutdown -h +15 "the server will shutdown in 15 minutes"
Broadcast message from root@final.free.com
    (/dev/pts/2) at 5:53 ...

The system is going down for halt in 15 minutes!
the server will shutdown in 15 minutes