Automate CPAN module installations

Posted on 2016-12-06 12:53:16
by Geert Vandeweyer

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Automate CPAN module installations

Posted on 2016-12-06 12:53:16
by Geert Vandeweyer

1. Problem

• You have an installation script that needs to install several cpan modules
• You don't want to stick around to wait for user input : [yes] 

2. Solution

I've found several options around that should allow you to automate the CPAN questions, but the only solution that worked was the combination below. It performs the following tasks:

• Set the default answer to YES, using an environment variable.
• Intialises CPAN, automatically selecting a mirror
• Installs modules using a custom perl script, that first tests if the module is not available yet.

#!/bin/bash

# set default answer to yes
export PERL_MM_USE_DEFAULT=1

# init cpan
perl -MCPAN -e 'my $c = "CPAN::HandleConfig"; $c->load(doit => 1, autoconfig => 1); $c->edit(prerequisites_policy => "follow"); $c->edit(build_requires_install_policy => "yes"); $c->commit'

# install modules
perl getCpanModules.pl 'Number::Format'

3. getCpanModules.pl

#!/usr/bin/env perl

## get command line arg
my $module = $ARGV[0];
if ($module eq '') {
	print "No Module name provided. Installer will exit.\n";
	exit();
}
eval
{
  ( my $toload = "$module.pm") =~ s/::/\//g;
  require $toload;
  $module->import();
};

unless($@)
{
	print "Module $module exists. Skipping installation\n";
	exit();
}
print "Installing $module from CPAN: \n";
system("perl -MCPAN -e 'install $module'");

CPAN, Installation, Perl