How to pass and use variables in a Makefile

Summary

$ FOO=1 make foo BAR=2

Note that make foo BAR will try and make foo and make bar.

Use a variable

Here is the sample file we’ll use for testing.

  • Makefile 
      foo:
    echo $(FOO)
    echo $${FOO}

Pass a variable

Use any approach below to get the same result.

Export environment variable

$ export FOO=bar
$ make foo

Pass environment

$ FOO=bar make foo

Pass known param to make

$ make foo FOO=bar

Result

Here is the output printed from any of the above commands:

echo bar
bar
echo ${FOO}
bar