多进程：

#!/usr/bin/perl

use strict;
use warnings;

print "Starting main program\n";
my @childs;

for ( my $count = 1; $count <= 10; $count++) {
	my $pid = fork();
	if ($pid) {
		# parent
		#print "pid is $pid,parent $$\n";
		push(@childs,$pid);
	} 
	elsif ($pid == 0) {
		# child
		sub1($count);
		exit 0;
	} 
	else{
		die "couldnt fork: $!\n";
	}
}

foreach (@childs) {
	my $tmp = waitpid($_,0);
	print "done with pid $tmp\n";
}       

print "End of main program\n";

sub sub1 {
	my $num = shift;
	print "started child process for  $num\n";
	sleep $num;
	print "done with child process for $num\n";
	return $num;
} 

多线程：

#!/usr/bin/perl

use strict;
use warnings;
use threads;
use threads::shared;

print "Starting main program\n";

my @threads;
for ( my $count = 1; $count <= 10; $count++) {
	my $t = threads->new(\&sub1,$count,"hello,word");
	push(@threads,$t);
}
foreach (@threads) {
	my $num = $_->join;
	print "done with $num\n";
}
print "End of main program\n";

sub sub1 {
	my ($num,$str) = @_;
	print "started thread $num,$str\n";
	sleep $num;
	print "done with thread $num\n";
	return $num . " haha...";
}