...
    use constant LEVEL_1_LOOP_MAXIMUM => 1400;  # This code keeps the 
+program from looping forever.
    my $level_1_loop_counter;
  FOLLOW_LEVEL_1_LINK:
    for (
        $level_1_loop_counter = 1 ;
        $level_1_loop_counter <= LEVEL_1_LOOP_MAXIMUM ;
        $level_1_loop_counter++
      )
    {

        #------------------------------------------
        print $fh_log "Level_1_loop_counter: $level_1_loop_counter\n";
        if ( $level_1_loop_counter > LEVEL_1_LOOP_MAXIMUM ) {
            die "Runaway program.\n";
        }
        ...
[download]

Notice the belt and suspenders approach.