Multiple ways to take IP addresses from Linux commands

The following command environment is the centos6.6 system;

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[[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:361/64Scope: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/loopback00:00:00:00:00:00 brd 00:00:00:00:00:00    inet 127.0.0.1/8scope host lo    inet6 ::1/128scope host       valid_lft forever preferred_lft forever2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000    link/ether00:0c: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:361/64scope 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

Get "(Labor income, do not like to spray)"

Multiple ways to take IP addresses from Linux commands