#!/usr/bin/perl
use strict;
use warnings;
require 'sys/syscall.ph';

my $buffer = "                ";

open my $f, '</dev/null' or die "open: $!";

# This works
syscall(&SYS_read, fileno($f), $buffer, 1) != -1 or warn "write: $!";
defined read($f,  $buffer, 1) or die "First pass, read: $!";

# This closes $f
syscall(&SYS_read, fileno($f), $buffer, 1, $f) != -1 or warn "write: $!";
defined read($f,  $buffer, 1) or die "Second pass, read: $!";