Use IO::Handle;

pipe(READHANDLE, WRITEHANDLE);

WRITEHANDLE->autoflush(1);
READHANDLE->autoflush(1);

if ($processed = fork) {
   close(READHANDLE);
   print WRITEHANDLE "Here is some text";
   close(WRITEHANDLE);
   waitpid($processed, 0);
} else {
   close(WRITEHANDLE);
   while (defined($text = <READHANDLE>)) {
      print $text;
   };
   exit;
}