+function file_lock($fname, $is_exclusive)
+{
+ if (($res = fopen($fname, "r+")) == FALSE) {
+ return (FALSE);
+ }
+
+ if (flock($res, ($is_exclusive ? LOCK_EX : LOCK_SH)) == FALSE) {
+ fclose($res);
+ return (FALSE);
+ }
+
+ return ($res);
+}
+
+function file_unlock($res)
+{
+ if ($res != FALSE) {
+ flock($res, LOCK_UN);
+ fclose($res);
+ }
+}
+