use strict;
use warnings;
use POSIX;
use POSIX "sys_wait_h";

local $SIG{CHLD} = \&REAPER;

my $wert = system('ls');
print "Rueckgabe: $wert\n";

if ($wert == 0) {
   print "Ok\n";
}
else {
   print "Fehler\n";
}
exit 0;

sub REAPER {
  my $sig = shift;
  my $pid;
  while (($pid = waitpid(-1, WNOHANG)) > 0) {
    print "child $pid terminated - status $?\n";
    print "sig: $sig\n";
  }
  $SIG{CHLD} = \&REAPER;
}