Question

I have a bash script which iterates through different sub-projects directories and executes make target there.

Each of that makefile can have its own variable e.g. $(MY_FILTERS) assigned withing the makefile. So it is a makefile’s internal variable.

Is there a way I can export such variable to add it’s content to some system/shell variable accessible from the main script?

I hope this is not the case of parent process not being able to be modified by sub process??

Answer 1

I hope this is not the case of parent process not being able to be modified by sub process??

Hopes dashed, sorry, you have to use some sort of IPC. This is one way to do it:

#!/bin/bash
export pipe="/tmp/mypipe.$$"
trap 'rm "$pipe"' EXIT 
mkfifo "$pipe" 

make &

read myfilters < "$pipe"
echo "myfilters is $myfilters" 

Makefile:

all:
    echo ${MY_FILTERS} > ${pipe}

(note that the echo is indented with a tab)