while (1) {
        pipe(READER,WRITER);
        READER->autoflush(1);
        WRITER->autoflush(1);

        my $pid = fork();

        if($pid == 0){
                # Child-Prozess
        
                close READER;
                print WRITER $$;
                print "Ich bin das Kind:  ",$$,"\n";
                my $output = system("/usr/bin/firefox file:///home/uname/log/testseite.html");
                # print $output;                
                exit(0);
        }
        else{
                # Parent-Prozess
                print "Ich bin der Vater: ",$$,"\n";
                wait();

                close WRITER;

                my $i = 0;

                my @line = <READER>;
                while (1) {
                        print "$i Ich bin der Vater: ",$$,"\n";
                        print "$i Und mein Kind ist: ",$line[0],"\n";
                        $i++;
                        sleep(1);
                        if ($i >= 5) {
                                $i = 0;
                                exit(0);
                                # Child killen !
                        }
                }
        }
        print "besser dann doch abbrechen.";
        sleep(1);
}

my @line = <READER>;

my @line = <READER>;

use strict;
use warnings;
use POSIX;
use constant TIMEOUT => 20;

my $firefox;
unless ($firefox = fork) {
  die "Failed to fork: $!" unless (defined $firefox);
  exec '/woimmer/ich/bin/firefox', 'http://www.example.com/';
  die "Failed to spawn firefox: $!";
}
else {
  # remember time the browser was started
  my $start = time;
  my $remaining = TIMEOUT;

  # only loop while the browser is still running and the timeout is not over
  while (waitpid($firefox, WNOHANG) < 0 and $remaining > 0) {
    sleep $remaining;
    $remaining = $start + TIMEOUT - time;
  }

  # send the browser a TERM signal
  kill TERM => $firefox;
  # clean up the zombie process
  die "Problems cleaning up the browser process: $!" if (waitpid($firefox, 0) < 0);
}

unless(open(READ '-|')){
 while(1){
  print STDOUT "kind\n";
  sleep(1);
 }
}else{
 sleep(5);
 my @child=<READ>;
 print "@child";
 close(READ);
}
exit();

#!/usr/bin/perl

use POSIX;
use warnings;
use strict;

my $file = "lines.txt";
open(LINES, "<$file");

my @ar_lines = <LINES>;
print $ar_lines[0]."\n";
foreach my $link (@ar_lines) {
        print $link."\n";
        my $pid = fork();

        if($pid == 0){
                # Child-Prozess 
                print "Ich bin das Kind:  ",$$,"\n";

                # hier zu öffnender link, klappt alles nicht, auch nicht mit Backticks
                # my $ret_val = system("/usr/bin/firefox $link");
                # my $ret_val = exec("/usr/bin/firefox $link");
                # my $ret_val = `/usr/bin/firefox $link &`;
                # my $ret_val = system("/usr/bin/firefox $link &");
                system("/usr/bin/firefox test.html");

                sleep(35);
                exit(0);
        } else {
                # Parent-Prozess
                print "Ich bin der Vater: ",$$,"\n";    
                waitpid($pid, 0);

                print "Ich bin der Vater: ",$$,"\n";
                print "Und mein Kind ist: ",$pid,"\n";
        }
        sleep(20);
}