How can I use a script to change the static IP address?

Question

How do I change the IP address of an interface from a script?

I should say that I don't want to use ifconfig and also I don't want to edit the /etc/network/interfaces file manually. I need a script.

Answer 1

If you are using ifup to configure the interface then you can define multiple so-called logical interface definitions for the interface and switch among them using ifup and ifdown. For example, you can define "iface home" and "iface work" in /etc/network/interfaces and then bring up eth0 either with "ifup eth0=home" or "ifup eth0=eth0-work". See ifup(8). Example of doing this from a script follows.

#!/bin/sh
ifdown eth0
ifup eth0=home

If you are using NetworkManager to configure the interface then you can define multiple so-called connections and switch between them using the nmcli command.

#!/bin/sh
nmcli con down id  'Wired connection work'
nmcli con up id  'Wired connection home'

If you are using neither ifupdown nor NetworkManager and you don't want to use ifconfig then you can use the ip utility. See ip(8).

#!/bin/sh
ip link set dev eth0 ...