use warnings;
use subs 'die'; 

#our own print, but it doesn't override the built-in
sub print {
CORE::print scalar(localtime),": "; 
CORE::print(@_);
}

#our own die, will override the built-in
sub die { print "goodbye cruel world\n";}

#calls our custom print
#notice you have to use &print() notation
&print( "hello world\n");

#calls built in print
print "goodbye\n";

#calls our overriden die
die "hello";

##</code><code>##

Mon May 28 10:41:21 2001: hello world
goodbye
goodbye cruel world

##</code><code>##

#mydie.pm
#a package to export a global die, overriding the perl builtin
#reference perldoc perlsub
package mydie;
require Exporter;
use vars qw/@ISA @EXPORT/;
  
@ISA = 'Exporter';
@EXPORT_OK = qw/die/;
	  
sub import {
	my $pkg = shift;
	return unless @_;
	my $sym = shift;
	my $where = ($sym =~ s/^GLOBAL_// ? 'CORE::GLOBAL' : caller(0));
	$pkg->export($where, $sym, @_);
	Exporter::import($pkg,@_);
}
				  
sub die {
	print "goodbye cruel world\n";
	CORE::die $_[0];
}

##</code><code>##

#!/usr/local/bin/perl
use warnings;
use strict;
use mydie qw(die);

print "hello world\n";
#calls the die exported by mydie.pm
die "argh!!!";

##</code><code>##

hello world
goodbye cruel world
argh!!! at mydie.pm line 20.