Installing Perl modules

Many Perl modules have numerous dependencies, and different modules can have conflicting dependencies. The current ‘best practices’ regarding Perl modules is therefore to install your own modules, and even have separate modules installed for different projects/programs. Thus, on our HPC systems, we only install a small set of modules that are heavily used, or are compiled against special versions of libraries.

It is easy to install your own Perl modules. Most Perl modules are available on CPAN. This section describes how you can install Perl modules from CPAN in your home directory.

# First load an appropriate Perl module (use `module avail Perl` to see all)
module load Perl/5.32.0-GCCcore-10.2.0
# Make Perl install Perl modules in your $HOME:
eval $(perl -Mlocal::lib)
# `PERL_CPANM_HOME` is the directory where cpanm builds the modules, not where they are installed
export PERL_CPANM_HOME=/tmp/cpanm_$USER
# Install for example Perl module Chess:
cpanm Chess

Other useful commands

# Check if the Perl module installed correctly:
perl -MChess -e ’print "ok\n"’
# Check all installed Perl modules:
instmodsh
cmd? l
# Check where a Perl module is installed:
cmd? m Chess
d
# Uninstall a Perl module:
cpanm --uninstall Chess

Advanced Options

Install from local file:

wget http://www.cpan.org/authors/id/M/MA/MAKAMAKA/JSON-2.90.tar.gz
cpanm JSON-2.90.tar.gz

Install to a separate directory (good for keeping projects separate or have in a shared directory):

eval $(perl -Mlocal::lib=/the/path)
cpanm Some::Module