CPAN Local Directories and Files

Perl Tutorials - Herong's Tutorial Examples

∟CPAN (Comprehensive Perl Archive Network)

∟CPAN Local Directories and Files

This section provides an introduction of local directories and files used when installing Perl modules from the CPAN repository.

If you are using the CPAN shell or "cpan" command to install and manage Perl modules, it will create a number of local directories and files:

The working directory - .cpan, located in your home directory. It contains sub-directories and files to support the CPAN working sessions:

build - Sub-directory to hold working files when installing a Perl module.
CPAN - Sub-directory to hold CPAN local configuration.
metadata - Database file to hold information about the CPAN repository.
sources - Sub-directory to hold information about Perl module packages and authors.

The lock file - .cpan/.lock, located in your home directory. It is used as locker to ensure that there is only a single CPAN session running.

home/herong/.cpan/.lock

Installation locations - Located in /usr/local directory. That's where Perl modules will be installed.

Perl uses 3 sets of variables to control where modules are installed:

1. "perl" - For standard modules included with Perl itself.

# build specific modules
installarchlib='/usr/lib/x86_64-linux-gnu/perl/5.26';

# generic modules
installprivlib='/usr/share/perl/5.26';

2. "vendor" - For modules installed by the provider of your Perl engine.

# build specific modules
installvendorarch='/usr/lib/x86_64-linux-gnu/perl5/5.26';

# generic modules
installvendorlib='/usr/share/perl5';

3. "site" - For modules installed using CPAN.

# build specific modules
installsitearch='/usr/local/lib/x86_64-linux-gnu/perl/5.26.1';

# generic modules
installsitelib='/usr/local/share/perl/5.26.1';

You can use the "-V" option to view Perl variables:

herong$ perl -V:'install.*'

installarchlib='/usr/lib/x86_64-linux-gnu/perl/5.26';
installprivlib='/usr/share/perl/5.26';
installvendorarch='/usr/lib/x86_64-linux-gnu/perl5/5.26';
installvendorlib='/usr/share/perl5';
installsitearch='/usr/local/lib/x86_64-linux-gnu/perl/5.26.1';
installsitelib='/usr/local/share/perl/5.26.1';
...

You can get a list of installed Perl modules from the CPAN repository by looking at the installation locations:

herong$ ls -l /usr/local/lib/x86_64-linux-gnu/perl/5.26.1
  drwxrwxr-x 37 root root   4096 Sep  2 09:49 auto
  drwxrwxr-x  3 root root   4096 Sep  2 09:47 Class
  drwxrwxr-x  2 root root   4096 Sep  2 09:50 DateTime
  -r--r--r--  1 root root 137251 Feb 18  2025 DateTime.pm
  drwxrwxr-x  2 root root   4096 Sep  2 09:46 Devel
  drwxrwxr-x  2 root root   4096 Jul  9  2023 Digest
  drwxrwxr-x  3 root root   4096 Sep  2 09:44 List
  ...

herong$ ls -l /usr/local/share/perl/5.26.1
  drwxrwxr-x  2 root root  4096 Sep  2 09:48 Capture
  drwxrwxr-x  5 root root  4096 Sep  2 09:49 Class
  drwxrwxr-x  3 root root  4096 Sep  2 09:44 CPAN
  drwxrwxr-x  4 root root  4096 Sep  2 09:49 DateTime
  drwxrwxr-x  3 root root  4096 Sep  2 09:46 Devel
  drwxrwxr-x  2 root root  4096 Jul  9  2023 Digest
  -r--r--r--  1 root root 11225 Aug 24  2021 Digest.pm
  drwxrwxr-x  3 root root  4096 Sep  2 09:46 Dist
...