When working on a different system or if you happen to have forgotten what modules were installed to Perl, there are several ways to obtain a list of what modules are installed.
If this happened to you, you can use the following ways to list all modules installed to Perl.
Using instmodsh:
instmodsh
Use the 'l' option to list all installed modules & then 'q' to quit.
Using perldoc:
There are 2 commands, depending of the kind of Perl module:
perldoc perlmodlib
The above command lists the modules that come pre-installed with the standard Perl package.
perldoc perllocal
The above command lists the optional modules that are installed in your system that don't come with Perl by default. This commands will also include a large amount of useful information, such as the the installation date, directory it was installed, module version number, etc...
Using a script:
perl -MFile::Find=find -MFile::Spec::Functions -Tlw -e 'find { wanted => sub { print canonpath $_ if /\.pm\z/ }, no_chdir => 1 }, @INC'
Using ActivePerl:
ppm query
When you are using ActivePerl in Windows, the above command will list the modules installed.
List of where Perl is looking for modules:
perl -e'print join "\n", @INC'
You could then list the contents of those directories.