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Automatic module installation

by Juerd (Abbot)
on May 23, 2002 at 08:03 UTC ( #168693=CUFP: print w/replies, xml ) Need Help??

Let's assume you have a recent Perl and CPANPLUS installed. You want your brand new script to automatically install any modules that are not found. Well, maybe you don't. I'm sure I don't, but I couldn't resist the temptation and made The module name describes exactly what it does, or... no it doesn't... but I needed a name.

My first try had a $SIG{__DIE__} handler and die "Try again :)\n", but it still didn't look nice. I did this because you cannot resurrect scripts. Kane had the idea of using exec($^X, $0, @ARGV) instead, which worked perfectly. But then, lathos suggested using a code ref in @INC. With the help of this node, I created this:

use strict; use CPANPLUS; push @INC, sub { my ($code, $file) = @_; my $module = $file; $module =~ s!/!::!g; $module =~ s!\.pm$!!g; install($module); for (@INC) { next if ref; if (-e "$_/$file" and -r _) { open my $fh, '<', "$_/$file" or die $!; return $fh; } } return undef; };
Please note that real programmers don't use CPANPLUS but CPANPLUS::Backend, and use the great backend. I was lazy and used CPANPLUS with the simple install() function, but that is bad.

Example script:

use Blah; use Acme::Time::Baby; print babytime(), "\n";

Example output:

3;0 root@ouranos:/home/juerd/modtest# perl Checking if your kit is complete... Looks good Writing Makefile for Acme::Time::Baby PERL_DL_NONLAZY=1 /usr/bin/perl -Iblib/arch -Iblib/lib -I/usr/lib/perl +/5.6.1 -I/ usr/share/perl/5.6.1 -e 'use Test::Harness qw(&runtests $verbose); $ve +rbose=(eva l(chr(36).q(|=1))-1); runtests @ARGV;' t/*.t t/00_en..........ok t/01_du..........ok t/02_custom......ok t/03_noimport....ok t/04_chef........ok t/05_warez.......ok t/06_de..........ok t/07_fr..........ok t/08_no..........ok t/09_it..........ok All tests successful. Files=10, Tests=12972, 6 wallclock secs ( 2.33 cusr + 0.17 csys = 2 +.50 CPU) Installing of Acme::Time::Baby succesfull The big hand is on the eight and the little hand is on the ten 3;0 root@ouranos:/home/juerd/modtest# perl The big hand is on the nine and the little hand is on the ten

- Yes, I reinvent wheels.
- Spam: Visit eurotraQ.

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Re: Automatic module installation
by Corion (Pope) on May 23, 2002 at 09:11 UTC

    Abigail once did something similar in Re: The Future - Managing Modules with The::Net, except that Abigail didn't use CPANPLUS and that the module is not available on CPAN for reasons unknown to me. So a possible name for your module might either be The::Net indeed, as The::Net might be unclaimed at the moment (ask Abigail about this :-) ) or The::Net::CPANPLUS, as that is what you do.

    perl -MHTTP::Daemon -MHTTP::Response -MLWP::Simple -e ' ; # The $d = new HTTP::Daemon and fork and getprint $d->url and exit;#spider ($c = $d->accept())->get_request(); $c->send_response( new #in the HTTP::Response(200,$_,$_,qq(Just another Perl hacker\n))); ' # web

      Abigail once did something similar in Re: The Future - Managing Modules

      I knew that already. That node helped me to understand subrefs in @INC.

      And no, this isn't ever going into CPAN. I'm not even going to use it. Just wanted it to be possible :)

      - Yes, I reinvent wheels.
      - Spam: Visit eurotraQ.

      Not available on CPAN? So, what's in then? You won't find it when searching because 'The' isn't a registered namespace, and the search functionality isn't checking what has really been uploaded.

      Note that The::Net doesn't install the module - it will fetch it each time.

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