my $cmd_one = '';
my $cmd_two = '';
if(open(CMD_ONE,"$cmd_one |")){
  while(my $line = <CMD_ONE>){
    print "Ausgabe Prog1: ",$line,"\n";
  }
  close CMD_ONE;
  if(open(CMD_TWO,"$cmd_two |")){
    while(my $line = <CMD_TWO>){
      print "Ausgabe Prog2: ",$line,"\n";
    }
    close CMD_TWO;
  }
  else{
    print $cmd_two," konnte nicht ausgeführt werden! \n";
  }
else{
  print $cmd_one," konnte nicht ausgeführt werden!\n";
}