use strict;

my ($start_time, $end_time, $time_used);
my $input;

print "Hit enter to start\n";
while (<STDIN> !~ /q/) {
  $start_time = time;

  print "Hit enter to stop\n";
  $input = <STDIN>;
  $end_time = time;
  $time_used = $end_time - $start_time;

  print "That took $time_used\n";
  print "Hit enter to start, q <enter> to quit\n";
}