How can I find the version of an installed Perl module?

Solution 1:

Most modules (especially ones from The CPAN) have a $VERSION variable:

perl -MSome::Module -le 'print $Some::Module::VERSION'

Solution 2:

Why are you trying to get the version of the module? Do you need this from within a program, do you just need the number to pass to another operation, or are you just trying to find out what you have?

I have this built into the cpan (which comes with perl) with the -D switch so you can see the version that you have installed and the current version on CPAN:

$ cpan -D Text::CSV_XS

Text::CSV_XS
-------------------------------------------------------------------------
        Fast 8bit clean version of Text::CSV
        H/HM/HMBRAND/Text-CSV_XS-0.54.tgz
        /usr/local/lib/perl5/site_perl/5.8.8/darwin-2level/Text/CSV_XS.pm
        Installed: 0.32
        CPAN:      0.54  Not up to date
        H.Merijn Brand (HMBRAND)
        [email protected]

If you want to see all of the out-of-date modules, use the -O (capital O) switch:

$ cpan -O
Module Name                                Local    CPAN
-------------------------------------------------------------------------
Apache::DB                                0.1300  0.1400
Apache::SOAP                              0.0000  0.7100
Apache::Session                           1.8300  1.8700
Apache::SizeLimit                         0.0300  0.9100
Apache::XMLRPC::Lite                      0.0000  0.7100
... and so on

If you want to see this for all modules you have installed, try the -a switch to create an autobundle.

Solution 3:

VERSION is a UNIVERSAL method of all Perl classes. You can use it to get the module version (if it has been set which it usually has).

Here is a one liner where you only have to add the module name once:

perl -le 'eval "require $ARGV[0]" and print $ARGV[0]->VERSION' Some::Module

Solution 4:

There is a less-typing trick, that works provided your module doesn't have something insane like a Unix timestamp as a version number.

perl -MFoo::Bar\ 9999

This works because what it translates to is

use Foo::Bar 9999;

i.e. a version of Foo::Bar that's at least version 9999 or newer. And what you get is

Foo::Bar version 9999 required--this is only version 1.1.
BEGIN failed--compilation aborted.

(Neat trick I learned from Matt Trout.)