#!/usr/bin/perl -w

use warnings;
use Benchmark;

my $current_time = time();
my $filename = "test.txt";

sub file_open {
       open (FILE, "$filename");
       close FILE;
}

sub stat_change {
       utime($current_time, (stat($filename))[9], $filename);
}

timethese(3000000, {'openfile' => file_open(), 'changestat' => stat_change()});

##</code><code>##

[11:08:40 jhorner@gateway scripts]$ ./20000619-1.pl 
Benchmark: timing 3000000 iterations of changestat, openfile...
changestat:  0 wallclock secs ( 0.40 usr +  0.00 sys =  0.40 CPU) @ 7500000.00/s (n=3000000)
            (warning: too few iterations for a reliable count)
  openfile:  0 wallclock secs (-0.33 usr +  0.00 sys = -0.33 CPU) @ -9090909.09/s (n=3000000)
            (warning: too few iterations for a reliable count)

##</code><code>##

#!/usr/bin/perl -w

use warnings;
use Benchmark;

my $current_time = time();
my $filename = "test.txt";

sub file_open {
        open (FILE, "$filename");
        close FILE;
        my $i;
        $i++;
}

sub stat_change {
        utime($current_time, (stat($filename))[9], $filename);
        my $i;
        $i++;
}

timethese(3000000, {'openfile' => file_open(), 'changestat' => stat_change()});

##</code><code>##

[11:10:32 jhorner@gateway scripts]$ ./20000619-1.pl 
Benchmark: timing 3000000 iterations of changestat, openfile...
changestat:  1 wallclock secs ( 0.88 usr +  0.00 sys =  0.88 CPU) @ 3409090.91/s (n=3000000)
  openfile:  2 wallclock secs ( 0.91 usr +  0.00 sys =  0.91 CPU) @ 3296703.30/s (n=3000000)