implement %y and %C specifiers in strptime

src/time/strptime.c

@@ -11,6 +11,7 @@ char *strptime(const char *restrict s, const char *restrict f, struct tm *restri
 	int i, w, neg, adj, min, range, *dest, dummy;
 	const char *ex;
 	size_t len;
+	int want_century = 0, century = 0;
 	while (*f) {
 		if (*f != '%') {
 			if (isspace(*f)) for (; *s && isspace(*s); s++);
@@ -40,9 +41,9 @@ char *strptime(const char *restrict s, const char *restrict f, struct tm *restri
 			if (!s) return 0;
 			break;
 		case 'C':
-			/* FIXME */
-			dest = &dummy;
+			dest = &century;
 			if (w<0) w=2;
+			want_century |= 2;
 			goto numeric_digits;
 		case 'd': case 'e':
 			dest = &tm->tm_mday;
@@ -135,14 +136,15 @@ char *strptime(const char *restrict s, const char *restrict f, struct tm *restri
 			if (!s) return 0;
 			break;
 		case 'y':
-			/* FIXME */
-			dest = &dummy;
+			dest = &tm->tm_year;
 			w = 2;
+			want_century |= 1;
 			goto numeric_digits;
 		case 'Y':
 			dest = &tm->tm_year;
 			if (w<0) w=4;
 			adj = 1900;
+			want_century = 0;
 			goto numeric_digits;
 		case '%':
 			if (*s++ != '%') return 0;
@@ -187,5 +189,9 @@ char *strptime(const char *restrict s, const char *restrict f, struct tm *restri
 			;
 		}
 	}
+	if (want_century) {
+		if (want_century & 2) tm->tm_year += century * 100 - 1900;
+		else if (tm->tm_year <= 68) tm->tm_year += 100;
+	}
 	return (char *)s;
 }