%INC的键和值是否依赖于平台?

既然它是一个标准模块,那么使用 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;
}

下面是一个相当健壮的实现,它也适用于尚未加载的模块。

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;