A pice of code which automatically will install perl dependencies

autoinstalldeps.pm

use IO::Socket::INET; use File::Basename; use File::Path; BEGIN {
our $SOURCE = $ENV{'AUTO_INSTALL_DEPS_SOURCE'} || 'http://api.metacpan.org:80/source/%s';
our $LIB = "$ENV{'HOME'}/.perl5";
push @INC, $LIB, sub {
    my($module) = $_[1] =~ /(.*)\.pm$/; $module =~ s!/!::!g; 
    my($hostname) = $SOURCE =~ m!//([^/]+)!;
    my $s = IO::Socket::INET->new(PeerAddr => $hostname) or die "Cannot download required library from $hostname: $@";
    File::Path::make_path(dirname "$LIB/$_[1]");
    open my $FH, '+>', "$LIB/$_[1]" or die "Write $LIB/$_[1]: $!";
    printf STDERR "GET $SOURCE HTTP/1.1\n", $module if $ENV{'AUTO_INSTALL_DEPS_DEBUG'};
    $s->send(sprintf "GET $SOURCE HTTP/1.1\r\nHost: $hostname\r\nConnection: close\r\n\r\n", $module);
    while(1) { $s->recv($_, 0xfff); m!HTTP/1.1 (\d+)! and $1 != 200 and return; s!^.*\r\n\r\n!!s and last }
    while(1) { print $FH $_; $s->recv($_, 0xfff); length or last }
    seek $FH, 0, 0; $FH;
} } 1;

How nice: No more asking the user to download pure perl dependencies after downloading a script :)
The idea is that the code above can bootstrap an application by downloading the missing modules from http://metacpan.org. The downloaded modules will be installed in $HOME/.perl5 which is not really portable, but this is more a proof of concept.