my $pid = open3( $wtr, $rdr, $err, $httpd, '-v' );
my ($version, $builtondate) = <$rdr>;

##</code><code>##

print readline $err;

##</code><code>##

Use of uninitialized value in <HANDLE> at ./test.pl line 248.
readline() on unopened filehandle at ./test.pl line 248.