Update: To clarify the solution I'm seeking -- it's not an alternative for the fork. I'm aware that there are probably better alternatives on Win32. The question is (I think): given that a fork has been done, is there a way of redirectly STDOUT safely in a way that doesn't also affect the parent so that system gets the right filehandle? If this can't be done, then IPC::Run3 will probably just need to skip the fork tests on Win32.

It can't be done, since perl just calls the win32 c runtime system

Demo

C:\>more perl.stdout.fork.pl
use strict;
use warnings;

if (my $pid=fork() ) {
    sleep(1);
    print "parent\n";
} else {
    close STDOUT;
    open STDOUT, '>'. __FILE__.'.temp' or die $!;
    print "print child$/";
    system("echo echo child"); # printed to console, not to .temp
}

C:\>perl perl.stdout.fork.pl
echo child
parent

C:\>more perl.stdout.fork.pl.temp
print child
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