#! perl -slw
use strict;
use threads;

sub test {
        system qq[ c:/windows/system32/sort.exe test.dat > sorted.dat ];
        open F, '<sorted.dat' or die $!;
        print "Via system:\n", do{ local $/; <F> };
        close F;
        
        print "Via backticks\n", `c:/windows/system32/sort.exe test.dat`;
        
        open F, "c:/windows/system32/sort.exe test.dat |" or die $!;
        print "Via pipe\n", <F>;
        close F;
}

async( \&test )->join;