#!/usr/bin/perl -w
use strict;

use Win32API::File qw(
    GetOsFHandle
    GetHandleInformation
    SetHandleInformation HANDLE_FLAG_INHERIT
    CloseHandle
);

if(  @ARGV  ) {
    # This is cat.pl
    warn "Started child...\n";
    for(  @ARGV  ) {
        if(  /\D/  ) {
        } elsif(  CloseHandle($_)  ) {
            warn "Closed $_!\n";
        } else {
            warn "Couldn't close $_: $^E\n";
        }
    }
    while(<STDIN>) {
        warn "Child read line...\n";
        print;
        warn "Child printed line...\n";
    }
    warn "Child done...\n";
    close STDOUT
        or  die "Can't close STDOUT: $!\n";
    close STDIN
        or  die "Can't close STDIN: $!\n";
    exit( 0 );
}

pipe *KIDIN,   *TOKID
    or  die "Can't create first pipe: $!\n";
pipe *FROMKID, *KIDOUT
    or  die "Can't create second pipe: $!\n";
open( STDIN, "<&", \*KIDIN )
    or  die "Can't dup2 KIDIN to STDIN: $!\n";
open( STDOUT, ">&", \*KIDOUT )
    or  die "Can't dup2 KIDOUT to STDOUT: $!\n";
close KIDIN
    or  die "Can't close KIDIN: $!\n";
close KIDOUT
    or  die "Can't close KIDOUT: $!\n";

# Here is the missing part:

SetHandleInformation( GetOsFHandle(\*TOKID), HANDLE_FLAG_INHERIT(), 0 )
    or  die "Can't disable inherit for TOKID: $^E\n";
SetHandleInformation( GetOsFHandle(\*FROMKID), HANDLE_FLAG_INHERIT(), 0 )
    or  die "Can't disable inherit for FROMKID: $^E\n";

system( 1, $^X, $0, 'cat' ) # GetOsFHandle(\*TOKID), GetOsFHandle(\*FROMKID) )
    or  die "Can't exec self: $!\n";
# sleep 1;
close STDIN
    or  die "Can't close STDIN: $!\n";
close STDOUT
    or  die "Can't close STDOUT: $!\n";
print TOKID "first line\nsecond line\n";
close TOKID
    or  die "Can't close TOKID: $!\n";
warn "closed TOKID\n";
my @result= <FROMKID>;
print STDERR "RESULT:\n", @result, "\n";
close FROMKID
    or  die "Can't close FROMKID: $!\n";