locks up until the perl program exits ... I just wrote a new perl program

Just a five cents - maybe I misundertood you, but if you want to prevent your program from hanging up in loop forever, you can use timer as a watchdog inside your perl program. The hanlder should exit if some global variable doesn't change, and when everything is going rigth, you explicitly change it in main program loop. This is just an example usage for the idea.

#!/usr/bin/env perl

use strict;
use warnings;

our $flag = 0;

$SIG{ALRM} = \&Watchdog;

sub Watchdog {
    print "--- Tick ".$main::flag++."---\n";
    if ($main::flag >3) {
        print "--- Bark! Bark! ---\n";
        exit 1;
    }
    alarm 1;
}

alarm 1;

while(1) {
    print "main loop...\n";
        while(1){};
    print "done\n";
    $main::flag = 0;
}
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