+
+int parse_fractional_part_u(const char **p, size_t digits, unsigned *res) {
+ size_t i;
+ unsigned val = 0;
+ const char *s;
+
+ s = *p;
+
+ /* accept any number of digits, strtoull is limted to 19 */
+ for(i=0; i < digits; i++,s++) {
+ if (*s < '0' || *s > '9') {
+ if (i == 0)
+ return -EINVAL;
+
+ /* too few digits, pad with 0 */
+ for (; i < digits; i++)
+ val *= 10;
+
+ break;
+ }
+
+ val *= 10;
+ val += *s - '0';
+ }
+
+ /* maybe round up */
+ if (*s >= '5' && *s <= '9')
+ val++;
+
+ s += strspn(s, DIGITS);
+
+ *p = s;
+ *res = val;
+
+ return 0;
+}