#!/usr/bin/perl -w
use strict;

my $begin = time();
open (BIG, "<fiveHundredMB") or die "cannot open file for 500MB read";
open (OUT, ">bigfile") or die "cannot open bigfile for write";

while (<BIG>)
{
   print OUT $_;
}

close OUT;
my $end = time();
print "elasped time for 500MB file is: ", $end-$begin, " seconds\n";

__END__
prints:
elasped time for 500MB file is: 13 seconds