I'd suggest you'd take a look at José's Guide for creating Perl modules, because there's clearly more information there that you'll need.
Search for "PREREQ_PM" in that document. I think you'll find what you want.
HTH.
Perhaps we should be suggesting resources that detail the use of the new methods that do not rely on ExtUtils::MakeMaker? At least that is the feeling I get from reading slides from Michael Schwern's presentation "MakeMaker is Doomed". In this talk he recommends Module::Build. The quote that stuck in my mind that stuck in my mind from those slides was when Michael Schwern says:
I'm sick of maintaining MakeMaker, let it fade away."
Perhaps I should get stuck into updating that tutorial or writing a new one.
Perhaps we should be suggesting resources that detail the use of the new methods that do not rely on ExtUtils::MakeMaker? At least that is the feeling I get from reading slides from Michael Schwern's presentation "MakeMaker is Doomed". In this talk he recommends Module::Build.MakeMaker cannot really begin to fade away until Module::Build is part of the Perl core distribution. I've heard talk that that will happen with 5.10, but, AFAICT, it hasn't happened yet. And the fading won't get really serious until Module::Build is so well established that established module-authors (myself included) feel compelled to start including Build.PL scripts in their CPAN distros along with Makefile.PL. Then, in a later version, we can begin to imagine not including MakeMaker in the core distribution. That's a long ways off, IMH.
Having peered into MakeMaker's innards, I can well appreciate what Schwern goes through in attempting to maintain it.
All that being said, what I would welcome (and what you are welcome to volunteer for) is a supplement to cog's tutorial which provides a point-to-point guide for building a Build.PL file to accomplish what a Makefile.PL does at least for a pure Perl distribution.
jimk
My recollection is that the first module that I tried to install that needed Module::Build actually installed it as a prereq. And even then you can write a Makefile.PL that is just a wrapper around Build.PL for those that can't or won't be able to use the new build stuff. Is this inaccurate?
Isn't this person that we are trying to help build a module distribution not an established module author anyway?
You can't automatically install it as a prerequisite unless you know how to install it. It's a bit of a Catch-22: you can't process a Build.PL until you have Module::Build, and you can't install Module::Build (for the first time, at least) with a Build.PL. :)
brian d foy
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Of course Schwern says ExtUtils::MakeMaker is dead. He's the one trying to kill it. It's still the workhorse that gets modules installed, though.
I'm not going to worry about it until Module::Build is in the standard distribution and enough people have upgraded their perl distros.
brian d foy
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Inside your Makefile.PL, you have a WriteMakefile function. That function takes a list of key-value pairs which it will use to figure out what's going on and what to do when a user tries to install the module.
Inside that function, you should see an entry for PREREQ_PM => {}. This part allows you to specify all of the prerequisite modules along with their minimum versions. For example, this little snippet requires Foo::Bar version 1.02 or greater, Baz::Quux 2.70 or greater, and any version of CGI.pm.
WriteMakefile(
#...
PREREQ_PM => {
Foo::Bar => 1.02,
Baz::Quux => 2.70,
CGI => 0,
}
#...
);
Tools such as CPAN.pm and CPANPLUS can use this information to automatically install and update dependencies.
If you'd like to discover the module versions that you have installed, you can use a quick command line (among hundreds of other ways):
$ perl -MCGI -le 'print CGI->VERSION' 3.04
If you have the latest version (1.05) of my cpan(1) utility, you can use the -D switch to get module details. This is handy not only to check your installed version of the module, but to see what CPAN thinks is the current version.
$ cpan -D CGI
CGI
---------------------------------------------------------------------
(no description)
L/LD/LDS/CGI.pm-3.15.tar.gz
/usr/local/lib/perl5/5.8.4/CGI.pm
Installed: 3.04
CPAN: 3.15 Not up to date
Lincoln D. Stein (LDS)
lstein@cshl.org
Good luck :)
brian d foy
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If you install the tools with CPAN.pm, my cpan script, or CPAN++, they can automatically handle the dependencies for you. Simply running the Makefile.PL script won't do that for you.
brian d foy
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If you'd like to discover the module versions that you have installed, you can use a quick command line (among hundreds of other ways):
$ perl -MCGI -le 'print CGI->VERSION' # prints: 3.04
Is there a similar trick for scripts installed from CPAN, such as cpan itself?
I ask because I just installed the latest Bundle::CPAN distro and, when I called perldoc -m cpan, I saw this:
# $Id: cpan,v 1.5 2005/12/24 00:59:08 comdog Exp $
... which leads me to believe that this is version 1.5, not version 1.05 as you suggest farther down in your posting.
(Or is this an artifact of the way you set your $VERSION?
my $VERSION = sprintf "%d.%02d", q$Revision: 296 $ =~ m/ (\d+) \. (\d+) /xg;
jimk
There isn't a similar trick for scripts unless the script is specially written for it. It would need methods (so, it has to be class), and it would need one named VERSION.
Don't be fooled by the CVS file revision number. The distro was cpan-1.5 (the latest is cpan-1.51) which I set in Makefile.PL. The 1.05 is a mistake.
The latest cpan script has a -v switch, though. :)
brian d foy
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