+int parent_of_path(const char *path, char **_r) {
+ const char *e, *a = NULL, *b = NULL, *p;
+ char *r;
+ bool slash = false;
+
+ assert(path);
+ assert(_r);
+
+ if (!*path)
+ return -EINVAL;
+
+ for (e = path; *e; e++) {
+
+ if (!slash && *e == '/') {
+ a = b;
+ b = e;
+ slash = true;
+ } else if (slash && *e != '/')
+ slash = false;
+ }
+
+ if (*(e-1) == '/')
+ p = a;
+ else
+ p = b;
+
+ if (!p)
+ return -EINVAL;
+
+ if (p == path)
+ r = strdup("/");
+ else
+ r = strndup(path, p-path);
+
+ if (!r)
+ return -ENOMEM;
+
+ *_r = r;
+ return 0;
+}
+
+