20 foreach my $layer(qw(:unix :stdio :perlio :crlf)){
21 my $base_fd = do{ open my $in, '<', $0 or die $!; fileno $in };
25 if ($_ > 1 && $layer =~ /^:(unix|stdio)$/) {
26 $::TODO = "[perl #56644] PerlIO resource leaks on open() and then :pop in :unix and :stdio"
28 open my $fh, "<$layer", $0 or die $!;
30 is fileno($fh), $base_fd, $layer;