#! perl -slw
use strict;
use threads;

sub test {
        my $t = shift;

        my $cmd = "c:/windows/system32/sort.exe test$t.dat";
        
        print "Thread $t\n";  # show things are in motion...

        sleep 1;  # kludge to insure all threads are up...

        system "$cmd >sorted$t.dat";

        open F, "<sorted$t.dat" or die $!;
        print "Via system:\n", do{ local $/; <F> };
        close F;
        
        print "Via backticks\n", `$cmd`;

        open F, "$cmd|" or die $!;
        print "Via pipe\n", <F>;
        close F;
}

sub spawnem
{
	my $t1 = async{ \&test(1); };
	my $t2 = async{ \&test(2); };
	my $t3 = async{ \&test(3); };
	my $t4 = async{ \&test(4); };

	$t1->join;
	$t2->join;
	$t3->join;
	$t4->join;
}

&spawnem;