#! /usr/local/bin/perl -w

use 5.006;
use strict;
use warnings;

use Switch;

my $exit = 0;

sub shell
{
   print $/; # Error goes away if you remove this line, or change to "\n";

   while(1)
   {
      switch ("cmd")
      {
         case /^quit/   { $exit = 1; }
         case /^help/   { help(); }
      }
      last if $exit;
   }
}