获取每个ip address/ifconfig接口命令的前3行Linux

Question

我正在尝试从某些虚拟机获取 ip address/ifconfig 的前 3 行 - 其中一些是运行在 Ubuntu 上，一些在 CentOS 上。

例如：

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9001
        inet 172.31.106.100  netmask 255.255.240.0  broadcast 172.31.111.255
        inet6 fe80::10c5:1dff:fec0:803e  prefixlen 64  scopeid 0x20<link>
        ether 12:c5:1d:c0:80:3e  txqueuelen 1000  (Ethernet)
        RX packets 7483  bytes 7706844 (7.3 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2998  bytes 470781 (459.7 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

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 1000  (Local Loopback)
        RX packets 12100  bytes 3865475 (3.6 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 12100  bytes 3865475 (3.6 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

从这行代码中，我只需要得到以下部分：

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9001
        inet 172.31.106.100  netmask 255.255.240.0  broadcast 172.31.111.255
        inet6 fe80::10c5:1dff:fec0:803e  prefixlen 64  scopeid 0x20<link>

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>

同样适用于 ip 地址命令。有什么方法可以使用 Linux 命令来实现吗？

非常感谢，

罗曼

Answer 1

您可以使用 sed 来做到这一点，

ifconfig | sed -En '/^[^[:space:]]/,+2p; /^[[:space:]]*$/p'

简要说明，

管道结果将由 sed
/^[^[:space:]]/,+2p: 搜索并打印不是以空白开头的行，同时打印以下2行
/^[[:space:]]*$/p：搜索并打印空行

获取每个ip address/ifconfig接口命令的前3行Linux

Get the first 3 lines of each ip address/ifconfig interface command Linux

linux

ipconfig

ifconfig