请教下关于resetstd方法的问题

global $STDOUT, $STDERR;
$handle = fopen(self::$stdoutFile, "a");
if ($handle) {
    unset($handle);
    @fclose(STDOUT);
    @fclose(STDERR);
    $STDOUT = fopen(self::$stdoutFile, "a");
    $STDERR = fopen(self::$stdoutFile, "a");
} else {
    throw new Exception('can not open stdoutFile ' . self::$stdoutFile);
}