#!/usr/bin/perl
use strict;
use warnings;
use Benchmark::Forking qw( timethese cmpthese ); # UnixOS
# use Benchmark qw(:all) ; # WindowsOS

sub test_grep {
    my @matched = grep { $_ =~ /AGGT/ } <>;

    if (@matched) {
	for(@matched) { chomp $_;
			print "Grep: " . length($_) . "\n";}
    }
    close ARGV if eof;
}

sub test_while {
    my $count;
    while (<>) {
	if ($_ =~ /^>hsa/){
	    chomp (my $line = <>);
	    $count .= length($line);
	    $count .= " ";
	}
    } continue {
	close ARGV if eof; # reset $. each file
    }
    print "While: " . $count . "\n";
}

# test_grep(); # Works fine separate but not combined
test_while(); # Works fine separate but not combined

__DATA__

$ perl test.pl test.txt
Grep: 107
Grep: 251
^C
$ perl test.pl test.txt
While: 107 251
^C
__END__

my $results = timethese( 2, { 'Grep' => sub {  },
			      'While' => sub {  },
			 },
			 'none'
    );
cmpthese( $results );