#!/usr/local/bin/perl -w --
use Benchmark qw(timethese clearallcache);

$FILENAME = "datafile.txt";
$TEXT = "lease";
$COUNT = 100;

clearallcache;
&timethese($COUNT, 
    { 'w/o study or /o' => \&fn1,
        'w/o study with /o' => \&fn2,
        'with study w/o /o' => \&fn3,
        'with study and /o' => \&fn4 } );

sub fn1 {
    &mystat($FILENAME);
    print(STDERR "Searching for $TEXT\t");
    open(DF, $FILENAME);
        my $count = 0;
        while ($line = <DF>) {
            $count++    if ($line =~ m/$TEXT/);
        }
        print(STDERR "fn1 : Lines found : $count\n");
    close(DF);
}
sub fn2 {
    &mystat($FILENAME);
    print(STDERR "Searching for $TEXT\t");
    open(DF, $FILENAME);
        my $count = 0;
        while ($line = <DF>) {
            $count++    if ($line =~ m/$TEXT/o);
        }
        print(STDERR "fn2 : Lines found : $count\n");
    close(DF);
}
sub fn3 {
    &mystat($FILENAME);
    print(STDERR "Searching for $TEXT\t");
    open(DF, $FILENAME);
        my $count = 0;
        while ($line = <DF>) {
            study($line);
            $count++    if ($line =~ m/$TEXT/);
        }
        print(STDERR "fn3 : Lines found : $count\n");
    close(DF);
}
sub fn4 {
    &mystat($FILENAME);
    print(STDERR "Searching for $TEXT\t");
    open(DF, $FILENAME);
        my $count = 0;
        while ($line = <DF>) {
            study($line);
            $count++    if ($line =~ m/$TEXT/o);
        }
        print(STDERR "fn4 : Lines found : $count\n");
    close(DF);
}
sub mystat {
    local($filename) = @_;
    print(STDERR "Filename : $filename\tSize : ", 
        (stat($filename))[7], 
        "\t");
}