Perl fork() example with multiple child processes involved

n_child_forking.pl

use strict;
use warnings;

my $spawn_processes = 5;
my $forked = 0;
my $err = 0;
print "($$) parent has started\n";

foreach(1..$spawn_processes) {
    my $child_pid = fork();
    if(defined $child_pid && $child_pid > 0) {
    	## Parent
        $forked++;
    } elsif(defined $child_pid){
        ## Child
        print "($$) has started\n";
        for(1..100000000) {
            my $x = $_ + 123;
        }
	## Never forget to exit since the finalization part
        ## should only be executed by the parent process
        exit;
    } else {
	## unable to fork
	$err++;
    }
}

## Only parent gets here
## Waiting for all the successful child processes to finish
for(1..$forked) {
    my $pid = wait();
    print "($$) $pid has finished\n";
}

print "$$ parent process has finished with:\n";
print " -> $forked child processes finishing just fine\n";
print " -> $err child processes breaking\n";