use strict;
use warnings;

use Time::HiRes qw(time);
use constant TIMEOUT => 1;

my $bigString = pack "C*", 33 .. 126;
$bigString = $bigString x 1_000_000;
my $time_to_die = time + TIMEOUT;

eval {
    local $SIG{ALRM} = sub { die "regex timed out at ", time, "\n" };
    alarm TIMEOUT;

    print "time to die at $time_to_die\n";
    print "begin regex at ", time, "\n";
    my ( $foo, $bar, $baz ) = $bigString =~ /(?{1})(abc).*(def).*(ghi)/;
    print "foo = $foo, bar = $bar, baz = $baz\n";
    print "end regex at ", time, "\n";

    alarm 0;
};

print "error while regex. $@\n" if $@;

use Benchmark qw(:all);

cmpthese ( 5, {
    'mit  ' => sub { $bigString =~ /(?{1})(abc).*(def).*(ghi)/ },
    'ohne ' => sub { $bigString =~ /(abc).*(def).*(ghi)/ }
} );