Multiple ways to take IP addresses from Linux commands

Often encountered in the command line to take the IP address, or write a script reference IP address, need to use the command to take out; The following method is adjusted according to the actual situation

The following command environment is the centos6.6 system;

[[email protected] ~]# ifconfig eth0eth0      link  encap:ethernet  hwaddr 00:0c:29:2a:03:61             inet addr:192.168.20.50  bcast:192.168.20.255  mask:255.255.255.0           inet6 addr: fe80::20c:29ff:fe2a:361/64  scope:link          up broadcast running  MULTICAST  MTU:1500  Metric:1           RX packets:339 errors:0 dropped:0 overruns:0 frame:0           TX packets:270 errors:0 dropped:0 overruns:0  carrier:0          collisions:0 txqueuelen:1000           rx bytes:30384  (29.6 kib)   TX bytes:30677  (29.9  KiB)           interrupt:18 base address:0x2000                       [[email protected] ~]# ip add1: lo: <loopback,up,lower_up > mtu 65536 qdisc noqueue state unknown    link/loopback  00:00:00:00:00:00 brd 00:00:00:00:00:00    inet 127.0.0.1/8  scope host lo    inet6 ::1/128 scope host        valid_lft forever preferred_lft forever2: eth0: <broadcast, Multicast,up,lower_up> mtu 1500 qdisc pfifo_fast state unknown qlen  1000    link/ether 00:0c:29:2a:03:61 brd ff:ff:ff:ff:ff:ff    inet  192.168.20.50/24 brd 192.168.20.255 scope global eth0    inet6  fe80::20c:29ff:fe2a:361/64 scope link       valid_lft  Forever preferred_lft forever

Grep+cut Method:

[Email protected] ~]# ifconfig eth0|grep ' inet addr: ' |cut-d:-f2|cut-d ' "-f1

192.168.20.50

Sed method: Replace with regular

[[email protected] ~]# ifconfig eth0|sed-nr ' 2s#^.*addr: (. *) Bca.*$#\1#g ' P
192.168.20.50

Sed method (not very well understood)

Match/inet/This line is replaced 2 times, replaced by empty, the rest is the IP address;

[Email protected] ~]# ifconfig eth0|sed-n '/inet/{s/.*addr://;s/. *//;p} '

192.168.20.50

Awk method:

[Email protected] ~]# ifconfig Eth0|awk '/inet addr:/ {print $} ' |awk-f: ' {print $} '

192.168.20.50

Awk a command method: (depending on the actual environment, check the IP row to adjust)

[[Email protected] ~]# IP add|awk-f ' [/]+ ' nr==8 {print $} '

192.168.20.50

This article is from the "Model Student's Learning blog" blog, please be sure to keep this source http://mofansheng.blog.51cto.com/8792265/1721127

Multiple ways to take IP addresses from Linux commands