usr207@cvs-srv:~/perl> cat dollar_null.pl
#!/usr/bin/perl
use strict;
use warnings;
print "Hier laeuft das Skript '$0'\n";
sleep 10;
system('ps');
$0 = "chrrrrrchrrrrchrrrr";
print "Hier laeuft das Skript '$0'\n";
sleep 10;
system('ps');
$0 = "tschuess";
print "Das wars dann von '$0'\n";
system('ps');

usr207@cvs-srv:~/perl> dollar_null.pl
Hier laeuft das Skript './dollar_null.pl'
  PID TTY          TIME CMD
 2173 pts/6    00:00:00 bash
 2340 pts/6    00:00:00 dollar_null.pl
 2341 pts/6    00:00:00 ps
Hier laeuft das Skript 'chrrrrrchrrrrchrrrr'
  PID TTY          TIME CMD
 2173 pts/6    00:00:00 bash
 2340 pts/6    00:00:00 dollar_null.pl
 2342 pts/6    00:00:00 ps
Das wars dann von 'tschuess'
  PID TTY          TIME CMD
 2173 pts/6    00:00:00 bash
 2340 pts/6    00:00:00 dollar_null.pl
 2343 pts/6    00:00:00 ps
usr207@cvs-srv:~/perl>