Makefile environment based on targets

Question

This code doesn't work:

$ cat Makefile
dev:
        AWS_PROFILE=foobar-$@ echo $$AWS_PROFILE

demo:
        AWS_PROFILE=foobar-$@ echo $$AWS_PROFILE

Based on my target, I want the AWS_PROFILE correctly setup for the commands in the target. How does one achieve this with GNU Make 4.2.1?

That works! but what about next lines, or do the next commands need to be ; seperated on one long line? — hendry, Apr 04 '19 at 08:23
Possible duplicate of [this](https://stackoverflow.com/questions/2711963/change-makefile-variable-value-inside-the-target-body) question. — AmeyaVS, Apr 04 '19 at 08:26
@hendry you can use line continuation (`\`) to break long lines. See my answer for an example. — Renaud Pacalet, Apr 04 '19 at 08:46
`what about next lines` You can use [.ONESHELL](https://www.gnu.org/software/make/manual/html_node/One-Shell.html). — Matt, Apr 04 '19 at 11:45

score 0 · Answer 1 · answered Apr 04 '19 at 08:45

Add a semi-colon before the echo command:

dev:
    AWS_PROFILE=foobar-$@; echo $$AWS_PROFILE

Each line of a recipe is sent to a different shell. So, if you want to propagate shell variables you must define and use them on the same line, in the same shell list. You could also use && or || to join your individual shell commands.

Note that, for better readability, you can use the line continuation:

dev:
    AWS_PROFILE=foobar-$@; \
    echo $$AWS_PROFILE

Makefile environment based on targets

1 Answers1