Are keys and values of %INC platform-dependent or not?

Question

I'd like to get the full filename of an included module. Consider this code:

package MyTest;

my $path = join '/', split /::/, __PACKAGE__;
$path .= ".pm";

print "$INC{$path}\n";

1;

---

$ perl -Ipath/to/module -MMyTest -e0
path/to/module/MyTest.pm

Will it work on all platforms?

perlvar

The hash %INC contains entries for each filename included via the do, require, or useoperators. The key is the filename you specified (with module names converted to pathnames), and the value is the location of the file found.

Are these keys platform-dependent or not? Should I use File::Spec or what? At least ActivePerl on win32 uses / instead of \.

Update: What about %INC values? Are they platform-dependent?

Answer 1

Given that it's a standard module, go with the approach from Module::Loaded:

sub is_loaded (*) { 
    my $pm      = shift;
    my $file    = __PACKAGE__->_pm_to_file( $pm ) or return;

    return $INC{$file} if exists $INC{$file};

    return;
}

sub _pm_to_file {
    my $pkg = shift;
    my $pm  = shift or return;

    my $file = join '/', split '::', $pm;
    $file .= '.pm';

    return $file;
}

Answer 2

Here's a reasonably robust implementation that will also work for modules that haven't been loaded yet.

use File::Find;
use File::Spec;

sub pkg2path (*) {
    my $file = join '[\\\/:]' =>
               map  "\Q$_"    =>
               split /::|'/   => "$_[0].pm";            # '

    /$file$/ and return File::Spec->rel2abs( $INC{$_} )
        for keys %INC;

    # omit the rest to only find loaded modules

    my $path; find {
        no_chdir => 1,
        wanted   => sub {
            $path = $_ and goto found if /$file$/
        }
    } => @INC;

    found: File::Spec->rel2abs($path or return)
}

say pkg2path Benchmark;
say pkg2path Devel::Trace;