automatically install missing modules from CPAN

Question

If I want to distribute a Perl script, what is the best way to painlessly install any required modules that are missing on the user's system? Extra credit if there is a way to even install/upgrade Perl itself if it is missing or "too old".

Answer 1

Auto-installing software is the best way to make both end users and sysadmins very angry with you. Forget about this approach.

You can simply ship all your dependencies with your application distro, the inc directory is customary.

Answer 2

Usually this ends with CPAN-like package creation. So, when you need to install all dependencies you type make installdeps

See perldoc perlmodlib Also Module::Install may be useful for you and some Makefile.PL example

Makefile.PL allows you to define deps and required perl version. Also you may add

use 5.010;

To your script in order to require minimal version of perl to run. See perldoc -f use for details.

Answer 3

Why not use pp (PAR Packager) that creates an executable. No need for Perl or anything on the target machine.

Answer 4

If you look at cpanminus, this you can install by simply executing one file:

curl -L http://cpanmin.us | perl - --self-upgrade

This might be the behaviour you're looking for; it's done with App::Fatpacker. Check it out:

https://metacpan.org/module/App::FatPacker