See @ARGV in perlvar resp. Getopt::Long if you want to take selected elements out of @ARGV.

I can't find any method to pass variables to the Makefile other than by the environment, but

• It's simple and clean to pass environment variable to the Makefile
• It's simple and clean to use environment variable in the Makefile (in sh, ksh, bash and zsh at least)
• The environment variables can be passed to the Perl script as arguments even if they were passed to the Makefile as environment variables.

$ cat echo.pl
#!/usr/bin/perl
print("$ARGV[0]\n");

$ cat Makefile
testing:
        echo.pl $(TEXT) > $@

$ TEXT=moo make testing
echo.pl moo > testing

$ cat testing
moo
[download]

I feel this meets your needs. If not, let us know how it doesn't.

Thanks for the input!

I use ExtUtils::MakeMaker, so messing with Makefile itself is something I'd like to avoid. If you think that env variables are something I can use to tweak the details of the build process without shame, then I'm very much satisfied. I'll simply take care of the environment variables in the script, that's no problem.

Thank you once again.

use strict; use warnings; print "Just Another Perl Hacker\n";

echo.pl $(TEXT) > $@

Note that you will have a really hard time making sure that there are no shell special characters in TEXT. Unfortunately, there is no such thing as system() with several arguments in make. I believe some make programs provide implementation-specific means for quoting strings. However, if you expect TEXT to have strange characters, you'd be better off using the environment.

pb:/tmp> cat Makefile
testing:
        @echo "extern : myvar='$(myvar)'"
        @echo "default: CPP='$(CPP)'"

pb:/tmp> make
extern : myvar=''
default: CPP='cc -E'

pb:/tmp> make myvar=Tim\ Towdy
extern : myvar='Tim Towdy'
default: CPP='cc -E'

pb:/tmp> make myvar=gcc  CPP='$(myvar)'
extern : myvar='gcc'
default: CPP='gcc'
[download]

Hell yeah, I was looking for exactly this. I'll add this mechanism and keep the environment variables for compatibility with dumber make's. Thanks pal.

Update: Oh wait, can I add this functionality from Makefile.PL?

use strict; use warnings; print "Just Another Perl Hacker\n";

The 'normal' way to pass run-time arguments to a make(1) script is via make(1) macros declared on the CLI e.g. if using Test::More, a verbose listing can be generated using either of the 2 following equivalent methods...

Assuming Windoze...

set TEST_VERBOSE=t
dmake test
[download]

Assuming sh (or variant thereof:-)...

export TEST_VERBOSE=t
dmake test
[download]

dmake test TEST_VERBOSE=t

Note that environment variables are referenced in the same way as macros within the make(1) script, hence CLI macros override any environment variable(s) of the same name.

HTH

Wow, then this means that... I can assume environment variables in the script and then with no change to the makefile use the format

make VAR=value

and it will work!

... goes and tests it ...

... and it works! :-)

Then my problem is solved and I need not do anything, only document it. :-)) Great, thanks.

use strict; use warnings; print "Just Another Perl Hacker\n";