#!/usr/bin/perl
#
# the system call to cat is easy, but is it expensive?
#

use Benchmark qw( cmpthese timethese);
use warnings;
use strict;

my $basefilename='MB_of_zeros.dat';
my $filename;

sub cat_file { 
   my @file_contents = `cat $filename`;
}

sub open_file {
   open (FILE_CONTENTS, $filename);
   my @file_contents = <FILE_CONTENTS>;
}


foreach my $size (qw(1 10 100)) {
   $filename = $size . $basefilename;
   print "Reading $filename\n";
   cmpthese (-30, {     # number indicates seconds to run the test for (-5 is 5seconds) or total test runs to do (if number +)
      'Cat File'  => sub { cat_file()  },
      'Open_File' => sub { open_file() }, 
   });
}