How to pass argument to Makefile from command line?
How to pass argument to Makefile from command line?
I understand I can do
$ make action VAR="value"
$ value
with Makefile
VAR = "default"
action:
@echo $(VAR)
How do I get the following behavior?
$ make action value
value
How about
$make action value1 value2
value1 value2
You probably shouldn't do this; you're breaking the basic pattern of how Make works. But here it is:
action:
@echo action $(filter-out $@,$(MAKECMDGOALS))
%: # thanks to chakrit
@: # thanks to William Pursell
EDIT:
To explain the first command,
$(MAKECMDGOALS)
is the list of "targets" spelled out on the command line, e.g. "action value1 value2".
$@
is an automatic variable for the name of the target of the rule, in this case "action".
filter-out
is a function that removes some elements from a list. So $(filter-out bar, foo bar baz)
returns foo baz
(it can be more subtle, but we don't need subtlety here).
Put these together and $(filter-out $@,$(MAKECMDGOALS))
returns the list of targets specified on the command line other than "action", which might be "value1 value2".
Here is a generic working solution based on @Beta's
I'm using GNU Make 4.1 with SHELL=/bin/bash
atop my Makefile, so YMMV!
This allows us to accept extra arguments (by doing nothing when we get a job that doesn't match, rather than throwing an error).
%:
@:
And this is a macro which gets the args for us:
args = `arg="$(filter-out $@,$(MAKECMDGOALS))" && echo $${arg:-${1}}`
Here is a job which might call this one:
test:
@echo $(call args,defaultstring)
The result would be:
$ make test
defaultstring
$ make test hi
hi
Note! You might be better off using a "Taskfile", which is a bash pattern that works similarly to make, only without the nuances of Maketools. See https://github.com/adriancooney/Taskfile