求等效于pip freeze的Perl工具：获取指定目录下Perl模块及版本

Got it, let's figure out how to get that list of Perl modules (and their versions) from your custom install directory—just like Python's pip freeze --user does for user-specific packages. Here are a couple of solid methods to make this happen:

Method 1: Custom Perl Script (No Extra Dependencies) #

If you don't want to install any extra tools, a quick Perl script can traverse your target directory, parse module names, and pull their versions. This works with any standard Perl setup.

Save this as perl_freeze.pl:

#!/usr/bin/perl
use strict;
use warnings;
use File::Find;

# Replace this with your actual module directory
my $target_dir = '/soft/foo/1.0.0/lib/perl5';

# Walk through all .pm files in the directory
find(sub {
    # Skip non-.pm files
    return unless $_ =~ /\.pm$/;

    # Convert file path to Perl module name (e.g., Foo/Bar.pm → Foo::Bar)
    my $full_path = $File::Find::name;
    my $module_path = $full_path;
    $module_path =~ s/^\Q$target_dir\E//;  # Remove base directory
    $module_path =~ s/\.pm$//;             # Strip .pm extension
    $module_path =~ s/\//::/g;             # Replace slashes with ::
    $module_path =~ s/^:://;               # Clean up leading ::

    # Load the module and fetch its version
    eval {
        require $full_path;
        my $version = ${"${module_path}::VERSION"};
        # Handle modules without a defined VERSION
        print "$module_path==" . (defined $version ? $version : '0') . "\n";
    };
    # Warn if a module fails to load (e.g., missing dependencies)
    warn "Skipping $module_path: $@" if $@;
}, $target_dir);

Then run it with:

chmod +x perl_freeze.pl
./perl_freeze.pl

This will output lines like Data::Dumper==2.183—exactly the format you need for reproducibility.

Method 2: Use cpanm (If You Have It Installed) #

If you use cpanminus (a popular Perl package installer), you can leverage its built-in --list flag to get a clean list. First, point Perl to your custom directory, then run:

PERL5LIB=/soft/foo/1.0.0/lib/perl5 cpanm --list

This will output lines like Data::Dumper /soft/foo/1.0.0/lib/perl5/Data/Dumper.pm. If you want the Module==Version format, pipe it to a quick awk command to extract the version:

PERL5LIB=/soft/foo/1.0.0/lib/perl5 cpanm --list | awk '{
    module=$1;
    path=$2;
    # Run a tiny Perl command to get the version from the module file
    cmd="perl -e '\''require qq("$path"); print \$" module "::VERSION || 0'\''";
    cmd | getline version;
    close(cmd);
    print module "==" version;
}'

Notes to Keep In Mind #

• Some modules don’t define a $VERSION variable—both methods will default to 0 for these cases.
• If a module fails to load (e.g., it depends on another module not in your custom directory), the script will warn you but keep processing other modules.
• For binary Perl modules (in the arch subdirectory), the script will still handle their accompanying .pm files correctly.

内容的提问来源于stack exchange，提问作者Eric Deveaud