This seems crazy but it actually works! Tests show this only happens if the module doesn't use other modules or compile. If dependencies can be handled then Perl could use even more CPAN modules that are not installed! Thoughts? 

#!/usr/bin/perl -l
# Use a CPAN module that is *not* installed! Is this a good idea?
# Posted to perlmonks.org by an Anonymous Monk on Sun Jun 17 2018
#
# In this example, if the Astro::MoonPhase module is not installed,
# the use_cpan sub will parse the error, download the module page 
# from metacpan, parse that for the source code uri, download the
# raw module source, eval that string, and proceed normally as if 
# the module was installed! It does not work with all modules and 
# the concept is presented to the Monastery for contemplation.
#__QKB__

use strict;
use warnings;

eval { require Astro::MoonPhase };
use_cpan($@) if $@;

my @phases = Astro::MoonPhase::phasehunt();
print q~LOCALTIME     = ~, scalar localtime time;
print q~New Moon      = ~, scalar localtime $phases[0];
print q~First quarter = ~, scalar localtime $phases[1];
print q~Full moon     = ~, scalar localtime $phases[2];
print q~Last quarter  = ~, scalar localtime $phases[3];
print q~New Moon      = ~, scalar localtime $phases[4];

sub use_cpan
{
    my ($module) = @_;
    if ($module =~ /install the (\S+) module/) {
        my $modname = $1;
            require  HTTP::Tiny;
            my $pm = HTTP::Tiny->new->get("https://metacpan.org/pod/$m
+odname");
            for ($pm->{content} =~ /Source<\/a>\s*\(<a href="([^"]+)">
+raw/) {
                $pm = HTTP::Tiny->new->get($1);
            eval $pm->{content};
            last
        }
    }
}

[download]

Hack away...

In reply to Use a CPAN module that is not installed! Is this a good idea? by Anonymous Monk

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