+
+int sethostname_idempotent(const char *s) {
+ int r;
+ char buf[HOST_NAME_MAX + 1] = {};
+
+ assert(s);
+
+ r = gethostname(buf, sizeof(buf));
+ if (r < 0)
+ return -errno;
+
+ if (streq(buf, s))
+ return 0;
+
+ r = sethostname(buf, strlen(buf));
+ if (r < 0)
+ return -errno;
+
+ return 1;
+}