perlfaq3 shows how to do this with the ExtUtils::Installed module in "How do I find which modules are installed on my system?". There is also an example which uses the File::Find module, and a hint to look at the Module::CoreList module to identify core modules in different versions of perl.

Note: this particular FAQ is present in the docs for perl 5.8.7, but not in the docs for 5.6.1.

HTH

• Script to List all Install Modules
  See especially my reply that links many more related threads
• Installed Module

Super Search is your friend. You may also wish to look at the following:

What modules are we actually using?
Listing all installed modules
Finding All Installed Modules
Script to List all Install Modules

HTH,

Additionally there is the little known "instmodsh" (Installed Modules Shell) which comes with MakeMaker and I believe is installed these days with modern perls.

$ instmodsh
Available commands are:
   l            - List all installed modules
   m <module>   - Select a module
   q            - Quit the program
cmd? m YAML
Available commands are:
   f [all|prog|doc]   - List installed files of a given type
   d [all|prog|doc]   - List the directories used by a module
   v                  - Validate the .packlist - check for missing fil
+es
   t <tarfile>        - Create a tar archive of the module
   q                  - Quit the module
YAML cmd? d
all directories in YAML are:
   /usr/bin
   /usr/local/man/man1
   /usr/local/man/man3
   /usr/local/share/perl/5.8.7
   /usr/local/share/perl/5.8.7/Test
   /usr/local/share/perl/5.8.7/YAML
   /usr/local/share/perl/5.8.7/YAML/Dumper
   /usr/local/share/perl/5.8.7/YAML/Loader
YAML cmd?
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