+/** Create an alias to a jirafeau's link.
+ * @param $alias alias name
+ * @param $destination reference of the destination
+ * @param $password password to protect alias
+ * @param $ip client's IP
+ * @return a string containing the edit code of the alias or the string "Error"
+ */
+function jirafeau_alias_create($alias, $destination, $password, $ip)
+{
+ /* Check that alias and password are long enough. */
+ if (strlen($alias) < 8 ||
+ strlen($alias) > 32 ||
+ strlen($password) < 8 ||
+ strlen($password) > 32) {
+ return 'Error';
+ }
+
+ /* Check that destination exists. */
+ $l = jirafeau_get_link($destination);
+ if (!count($l)) {
+ return 'Error';
+ }
+
+ /* Check that alias does not already exists. */
+ $alias = md5($alias);
+ $p = VAR_ALIAS . s2p($alias);
+ if (file_exists($p)) {
+ return 'Error';
+ }
+
+ /* Create alias folder. */
+ @mkdir($p, 0755, true);
+ if (!file_exists($p)) {
+ return 'Error';
+ }
+
+ /* Generate password. */
+ $md5_password = md5($password);
+
+ /* Store informations. */
+ $p .= $alias;
+ $handle = fopen($p, 'w');
+ fwrite($handle,
+ $md5_password . NL .
+ $ip . NL .
+ time() . NL .
+ $destination . NL);
+ fclose($handle);
+
+ return 'Ok';