$ time perl -e 'open my $fh, "<", "words.txt" or die; my @w = <$fh>;
> my $c;
> foreach $line(@w) {
>   if ($line =~ /s.*h/i) {
>       if ( ($line =~ /s.*s/i) || ($line =~ /h.*h/i) ) {
>           next;
>       }
>       $c++;
>   }
> }
> print "$c \n";
> '
2834

real    0m0.138s
user    0m0.093s
sys     0m0.016s

##</code><code>##

$ time perl -e 'open my $fh, "<", "words.txt" or die;
> my $c;
> foreach $line(<$fh>) {
>   if ($line =~ /s.*h/i) {
>       if ( ($line =~ /s.*s/i) || ($line =~ /h.*h/i) ) {
>           next;
>       }
>       $c++;
>   }
> }
> print "$c \n";
> '
2834

real    0m0.120s
user    0m0.093s
sys     0m0.015s