windows - Why doesn't this fork loop work as expected? -

why following code:

#!/usr/bin/perl use strict; use warnings; use parallel::forkmanager;    $pm = new parallel::forkmanager(5);  @all_data = ('a','b','c','d','e','f');  foreach $data (@all_data) {     # forks , returns pid child:     $pid = $pm->start , next;      print "hello $pid\n";     $pm->finish; # terminates child process } $pm->wait_all_children;   

print:

hello 0   hello 0   hello 0   hello 0   hello 0   

i new perl , trying catch on multiprocessing in perl

from docs start method:

this method fork. returns pid of child process parent, , 0 child process.

as happens, fork function same, why start mirrors it.

the parent may need child pid control child – sending signals , stuff – child knows own pid via $$ variable:

foreach $data (@all_data) {     $pm->start , next;      print "hello $$\n";     $pm->finish; } 

example output:

hello 22215 hello 22218 hello 22219 hello 22217 hello 22220 hello 22216