How to run a bash script from a Makefile?

Question

I have a Makefile from which I want to call another external bash script to do another part of the building. How would I best go about doing this?

Answer 1

Each of the actions in the makefile rule is a command that will be executed in a subshell. You need to ensure that each command is independent, since each one will be run inside a separate subshell.

For this reason, you will often see line breaks escaped when the author wants several commands to run in the same subshell:

targetfoo:
        command_the_first foo bar baz
        command_the_second wibble wobble warble
        command_the_third which is rather too long \
            to fit on a single line so \
            intervening line breaks are escaped
        command_the_fourth spam eggs beans