1  use POSIX qw(setsid);
 2
 3  chdir '/'                 or die "Can't chdir to /: $!";
 4  umask 0;
 5  open STDIN, '/dev/null'   or die "Can't read /dev/null: $!";
 6  #open STDOUT, '>/dev/null' or die "Can't write to /dev/null: $!";
 7  open STDERR, '>/dev/null' or die "Can't write to /dev/null: $!";
 8  defined(my $pid = fork)   or die "Can't fork: $!";
 9  exit if $pid;
10  setsid                    or die "Can't start a new session: $!";
11
12  while(1) {
13     sleep(5);
14     print "Hello...\n";
15  }