#!perl -w
use strict;
use Win32API::File qw(:Func :HANDLE_FLAG_);

open my $fh,">&2";
my $os_handle=GetOsFHandle($fh) or die "Can't GetOSFHandle: $^E,\nstopped";
GetHandleInformation($os_handle, my $flags);
print "flags was=$flags\n";

print "HANDLE_FLAG_PROTECT_FROM_CLOSE=",HANDLE_FLAG_PROTECT_FROM_CLOSE,"\n";

$flags |= HANDLE_FLAG_INHERIT|HANDLE_FLAG_PROTECT_FROM_CLOSE;
print "Trying for flags=$flags\n";
SetHandleInformation($os_handle, $flags, $flags) or die "Can't
SetHandleInformation: $^E,\nstopped";

GetHandleInformation($os_handle, my $newflags);
print "flags now=$newflags\n";