Make: Capture output of shell command and return code at same time

Question

In make, if I want to capture the output of a shell command, I do something like this

RESULT:=$(shell $(COMMAND))

If I want to check if a command executed properly, I do this

RETURN_CODE := $(shell $(COMMAND); echo $$?)

How can I do both simultaneously, i.e. execute the command once, store the output, but also check the return code?

EDIT Duplicate here although his solution is not pleasant: Makefile: Output and Exitcode to variable?

Alex Cohn · Accepted Answer · 2014-07-09T18:24:24.417

6

What about

OUTPUT_WITH_RC := $(shell $(COMMAND); echo $$?)
RETURN_CODE := $(lastword $(OUTPUT_WITH_RC))
OUTPUT := $(subst $(RETURN_CODE)QQQQ,,$(OUTPUT_WITH_RC)QQQQ)

If your command fails, it will probably write to stderr; you can use this to capture everything:

OUTPUT_WITH_RC := $(shell $(COMMAND) 2>$1; echo $$?)

edited Jul 09 '14 at 18:24

answered Jul 09 '14 at 16:22

Alex Cohn

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Didn't know about lastword, that's certainly nicer than the sed used in the linked answer. Is there a nice way to then get the output without the return code? – pythonic metaphor Jul 09 '14 at 16:37
see update; use something that cannot appear in output instead of `QQQ` – Alex Cohn Jul 09 '14 at 18:22

Make: Capture output of shell command and return code at same time

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