While working on how to make a single user MUD-type text adventure, I decided to test real quick how to make it into a module. I had made some minor modules before, so I basically knew what to do. Before continuing, here is the code:

#!/usr/bin/perl
use strict;
use warnings;
package module;

my $state = 1;
my @exits = ("Major Motoko Kusanagi wishes you well!","Come back soon,
+ ya hear?","Bah, coward!","Go with God.","Stellaaaaaa!","Namo Kuan Yi
+n.");

sub welcome {
      print "Welcome to my game! Do you want to move:\n\n";
      print "North?\n";
      print "South?\n";
      print "East?\n";
      print "West?\n\n";
      }

sub movement {
      while ($state == 1) {
        welcome();
        print "<120/120hps 50/50mana 100/100mvs> ";
        chomp(my $move = <STDIN>);
        if ($move =~ /^(north|south|east|west)$/i) {
             print "\nYou have moved $move.\n\n";
           } elsif ($move =~ /^quit$/i) {
             print "\n$exits[rand @exits]\n\n";
             $state = 0;
           } else {
             print "\nThat is not a valid option.\n\n";
      }     
   }
}
movement();
1;
[download]

Okay, so I do everything I'm supposed to do, right? When I finally make a test script for it, and run it through perl -c, it actually executes the program, in addition to returning whether or not the syntax is ok.

After a bit of trial and testing of other things, looking through older modules, even looked in warning.pm, I finally figured out what the problem was:

I had left the invocation from the original script in, when I modified it to be a module! I took out the invocation movement(); and all was well.

So the lesson there is, sometimes the simplest things can trip you up, if you forget about them.

EDIT: Code updated, per ysth's recommendations.