Debian/Ubuntu 报错解决：-bash: ifconfig: command not found

晚上在虚拟机里安装了最新的 Debian 9，然后想查看ip地址的时候报错了：

[email protected]:~$ ifconfig
-bash: ifconfig: command not found

出现这个问题的原因是新版本的Debian 默认不带 ifconfig，官方推荐使用ip命令查看ip：

[email protected]:~$ ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
    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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:2b:61:d3 brd ff:ff:ff:ff:ff:ff
    inet 192.168.32.155/24 brd 192.168.32.255 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe2b:61d3/64 scope link 
       valid_lft forever preferred_lft forever

如果还想使用ifconfig命令，需要安装包：

sudo apt-get install net-tools

然后ifconfig会被安装：

[email protected]:/home/zhang# whereis ifconfig
ifconfig: /sbin/ifconfig /usr/share/man/man8/ifconfig.8.gz

你可以给ifconfig起个别名：

[email protected]:~$ alias ifconfig='/sbin/ifconfig'
[email protected]:~$ ifconfig 
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.32.155  netmask 255.255.255.0  broadcast 192.168.32.255
        inet6 fe80::20c:29ff:fe2b:61d3  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:2b:61:d3  txqueuelen 1000  (Ethernet)
        RX packets 527  bytes 44816 (43.7 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 394  bytes 55245 (53.9 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 1  (Local Loopback)
        RX packets 2  bytes 78 (78.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2  bytes 78 (78.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0