+int get_proc_cmdline_key(const char *key, char **value) {
+ _cleanup_free_ char *line = NULL, *ret = NULL;
+ bool found = false;
+ const char *p;
+ int r;
+
+ assert(key);
+
+ r = proc_cmdline(&line);
+ if (r < 0)
+ return r;
+
+ p = line;
+ for (;;) {
+ _cleanup_free_ char *word = NULL;
+ const char *e;
+
+ r = unquote_first_word(&p, &word, true);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ break;
+
+ /* Filter out arguments that are intended only for the
+ * initrd */
+ if (!in_initrd() && startswith(word, "rd."))
+ continue;
+
+ if (value) {
+ e = startswith(word, key);
+ if (!e)
+ continue;
+
+ r = free_and_strdup(&ret, e);
+ if (r < 0)
+ return r;
+
+ found = true;
+ } else {
+ if (streq(word, key))
+ found = true;
+ }
+ }
+
+ if (value) {
+ *value = ret;
+ ret = NULL;
+ }
+
+ return found;
+
+}
+