Re: saving matching pattern with flip-flop operator

[bart]

You could use $1, but I expect problems with retained old values if the regex didn't match.

So I prefer to directly, explicitly capture the captured value. Like this:

while (<>) {
    if(/START/ ... (my($time) = /END TIME (.+)/)) {
     unless(defined $time) {
        next if /START/ || /^\s*$/;
        print;
     } else {
        print "End time at $time\n";
     }
   }
}

BTW | is for bitwise or; you (ought to) want either or or ||.