V(3pm)

NAME
V - Print version of the specified module(s).

SYNOPSIS
    $ perl -MV=V

or if you want more than one

    $ perl -MV=CPAN,V

Can now also be used as a light-weight module for getting versions of modules without loading them:

    require V;
    printf "%s has version '%s'\n", "V", V::get_version ("V");

Starting with version 0.17, V will show all "package"s or "class"es in a file that have a version. If one wants to see all packages/classes from that file, set the environment variable "PERL_V_SHOW_ALL" to a true value.

If you want all available files/versions from @INC:

    require V;
    my @all_V = V::Module::Info->all_installed ("V");
    printf "%s:\n", $all_V[0]->name;
    for my $file (@all_V) {
        my ($versions) = $file->version; # Must be list context
        if (@$versions > 1) {
            say "\t", $file->name;
            print "\t    %-30s: %s\n", $_->{pkg}, $_->{version} for @versions;
            }
        else {
            printf "\t%-50s - %s\n", $file->file, $versions->[0]{version};
            }
        }

Each element in that array isa "V::Module::Info" object with 3 attributes and a method:

attribute name
    The package name.

attribute file
    Full filename with directory.

attribute dir
    The base directory (from @INC) where the package-file was found.

method version
    This method will look through the file to see if it can find a version assignment in the file and uses that to determine the version. As of version 0.13_01, all versions found are passed through the version module.

    As of version 0.16_03 we look for all types of version declaration:

        package Foo;
        our $VERSION = 0.42;

    and

        package Foo 0.42;

    and

        package Foo 0.42 { ... }

    Not only do we look for the "package" keyword, but also for "class". In list context this method will return an arrayref to a list of structures:

    pkg The name of the "package"/"class".

    version
        The version for that "package"/"class". (Can be absent if $PERL_V_SHOW_ALL is true.)

    ord The ordinal number of occurrence in the file.

DESCRIPTION
This module uses stolen code from Module::Info to find the location and version of the specified module(s). It prints them and exit()s.

It defines "import ()" and is based on an idea from Michael Schwern on the perl5-porters list. See the discussion:

  https://www.nntp.perl.org/group/perl.perl5.porters/2002/01/msg51007.html

  V::get_version($pkg)
Returns the version of the first available file for this package as found by following @INC.

Arguments

1. $pkg
    The name of the package for which one wants to know the version.

Response

This "V::get_version ()" returns the version of the file that was first found for this package by following @INC or "undef" if no file was found.

SEE ALSO
There are numerous module on CPAN that (try to) extract the VERSION from modules. ExtUtils::MakeMaker maybe being th most important inspiration. Module::Info was used to copy code from.

AUTHOR
 Abe Timmerman -- 2002 - 2024 (✝ 2024-08-15 😢)
 H.Merijn Brand C<< <hmbrand@cpan.org> >> (2026 ...)

COPYRIGHT AND LICENSE
Copyright 2024-2026 H.Merijn Brand, All Rights Reserved. Copyright 2002-2024 Abe Timmerman, All Rights Reserved.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANT-ABILITY or FITNESS FOR A PARTICULAR PURPOSE.