In Linux, how does one obtain ip addresses only through commands? in linux, how does one obtain ip addresses?

In Linux, how does one obtain ip addresses only through commands? in linux, how does one obtain ip addresses?

A friend of a colleague is taking the test. When he encounters such a problem, he can help solve the problem. As a result, the colleague finds him and helps him solve the problem. I really feel: in some aspects, I really don't know if it is a good thing! The question is roughly as follows. Generally, we use ifconfig to view the NIC information. What command can you use to output only the IP address 192.168.42.128?

A seemingly simple problem is not easy to implement. Let's take a look at the following ideas.

[root@DB-Server ~]# ifconfig eth0

eth0      Link encap:Ethernet  HWaddr 00:0C:29:9E:70:0E  

          inet addr:192.168.42.128  Bcast:192.168.42.255  Mask:255.255.255.0

          inet6 addr: fe80::20c:29ff:fe9e:700e/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:135 errors:0 dropped:0 overruns:0 frame:0

          TX packets:216 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000 

          RX bytes:14062 (13.7 KiB)  TX bytes:26007 (25.3 KiB)

 

[root@DB-Server ~]# ifconfig eth0 | grep "inet addr"

          inet addr:192.168.42.128  Bcast:192.168.42.255  Mask:255.255.255.0

This step is very simple, and we need to use awk to implement it, as shown below, to solve this problem.

[root@DB-Server ~]# ifconfig eth0 | grep "inet addr" | awk '{ print $2}'

addr:192.168.42.128

[root@DB-Server ~]# ifconfig eth0 | grep "inet addr" | awk '{ print $2}' | awk -F: '{print $2}'

192.168.42.128