今天笔试的题目。可惜啊，一时脑残，不记得
ifconfig eth0
的输出结果了。
ifconfig eth0 | grep IP
这个不对的吧？诶~ 
个人觉得面试不过是应该的：
ifconfig wlan0 | grep “inet addr”
myip () {
MY_IP=$(/usr/bin/ip addr show eth0 | awk '/inet/ { print $2 } ')
echo ${MY_IP:-"Not connected"}
}
怎么感觉ip的输出改了, inet后面没跟addr了
phoenix@Phoenix-X201i ~ % ifconfig
enp0s25: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.100 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::f2de:f1ff:fe39:6317 prefixlen 64 scopeid 0x20<link>
ether f0:de:f1:39:63:17 txqueuelen 1000 (Ethernet)
RX packets 195717 bytes 110037488 (104.9 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 165282 bytes 17962082 (17.1 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 20 memory 0xf2500000-f2520000
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 0 (Local Loopback)
RX packets 45 bytes 9632 (9.4 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 45 bytes 9632 (9.4 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
wlp2s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.106 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80::8ea9:82ff:fe02:a772 prefixlen 64 scopeid 0x20<link>
ether 8c:a9:82:02:a7:72 txqueuelen 1000 (Ethernet)
RX packets 371 bytes 93836 (91.6 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 24 bytes 3212 (3.1 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
phoenix@Phoenix-X201i ~ % ip addr
1: 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
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: enp0s25: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether f0:de:f1:39:63:17 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.100/24 brd 192.168.1.255 scope global enp0s25
valid_lft forever preferred_lft forever
inet6 fe80::f2de:f1ff:fe39:6317/64 scope link
valid_lft forever preferred_lft forever
3: wlp2s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
link/ether 8c:a9:82:02:a7:72 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.106/24 brd 192.168.1.255 scope global wlp2s0
valid_lft forever preferred_lft forever
inet6 fe80::8ea9:82ff:fe02:a772/64 scope link
valid_lft forever preferred_lft forever
只有 inet 和 inet6 看你要 v4 还是 v6
如果当然有电脑给我试试，也许可以改过来。and ifconfig eth0 | grep “inet addr” 出来的结果除了 IP 地址之外还有其它的一些东西，貌似可以用 awk 处理，不过不会 awk，我想，先把结果存档，然后用 sed 处理一下，应该也 ok 吧
ifconfig 的输出格式我见过两种了。
ip addr show enp3s0 | grep -oP ‘(?<=inet )\d.]+’
如果你的 grep 支持 -P 的话。
ip addr show eth0|sed -n '/inet /p'|awk '{print $2}'|sed 's/\/.*//g'
ifconfig eth0|awk -F':' '/inet addr/{print $2}'|awk '{print $1}'