CODEWITHSUNDEEP
linuxbashshellmakefile
CAJ
CAJ

Reputation: 301

using makefile variables in shell script without running make

We have a big make file that defines a lot of useful variables, like TEST_ENV. I'd like to make a shell script that lives in the same directory, and was wondering if there is any way to use the variables defined in the Makefile from the shell script. The variables I'm interested in are all defined like this

TEST_ENV := PATH=/path/to/thing \
            CONFDIR=/another/path

or

host_installdir = /still/a/path

The reason I want the script use the Makefile is so that if the variable ever needs to be changed inside the Makefile, the shell script won't get out of date.

I found this related question, but was hoping there might be a way to do this without having to run make first.

I considered the possibility of somehow using grep on the Makefile, but some of the variables are defined across multiple lines, which makes it tricky and breakable (for instance, if I do grep -A 3 for a variable defined across 3 lines, what if a 4th line is added later?).

Upvotes: 2

Views: 274

Answers (2)

Etan Reisner
Etan Reisner

Reputation: 80931

You could use (a modified version of) the print-% target from Makefile hacks: print the value of any variable in your makefile to let you query it for values.

print-%:
        @echo '$(subst ','\'',$($*))'

Upvotes: 2

John Kugelman
John Kugelman

Reputation: 361615

TEST_ENV=$(make -qp | awk -F' = ' '$1=="TEST_ENV" {print $2}')

I'm sure there are edge cases this doesn't handle, but it's a decent start. Rudimentary testing shows this handles multi-line variables.

Upvotes: 1

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