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authorRich Felker <dalias@aerifal.cx>2013-06-28 12:38:42 -0400
committerRich Felker <dalias@aerifal.cx>2013-06-28 12:38:42 -0400
commitaea79190326cf81d6c8ec81ab163137591c6dac8 (patch)
tree17132e9af070662887c0b0011c4baddb5c0db1c0 /src/time/strftime.c
parent062446a85db9b58b4900df82e17cb8c07ec50453 (diff)
downloadmusl-aea79190326cf81d6c8ec81ab163137591c6dac8.tar.gz
implement week-based-year year numbers in strftime
in the process, I refactored the week-number code so it can be used by the week-based-year formats to determine year adjustments at the boundary values. this also improves indention/code readability.
Diffstat (limited to 'src/time/strftime.c')
-rw-r--r--src/time/strftime.c61
1 files changed, 34 insertions, 27 deletions
diff --git a/src/time/strftime.c b/src/time/strftime.c
index b60197df..57687058 100644
--- a/src/time/strftime.c
+++ b/src/time/strftime.c
@@ -17,6 +17,32 @@ static int is_leap(int y)
return !(y%4) && ((y%100) || !(y%400));
}
+static int week_num(const struct tm *tm)
+{
+ int val = (tm->tm_yday + 7 - (tm->tm_wday+6)%7) / 7;
+ /* If 1 Jan is just 1-3 days past Monday,
+ * the previous week is also in this year. */
+ if ((tm->tm_wday - tm->tm_yday - 2 + 371) % 7 <= 2)
+ val++;
+ if (!val) {
+ val = 52;
+ /* If 31 December of prev year a Thursday,
+ * or Friday of a leap year, then the
+ * prev year has 53 weeks. */
+ int dec31 = (tm->tm_wday - tm->tm_yday - 1 + 7) % 7;
+ if (dec31 == 4 || (dec31 == 5 && is_leap(tm->tm_year%400-1)))
+ val++;
+ } else if (val == 53) {
+ /* If 1 January is not a Thursday, and not
+ * a Wednesday of a leap year, then this
+ * year has only 52 weeks. */
+ int jan1 = (tm->tm_wday - tm->tm_yday + 371) % 7;
+ if (jan1 != 4 && (jan1 != 3 || !is_leap(tm->tm_year)))
+ val = 1;
+ }
+ return val;
+}
+
size_t strftime(char *restrict s, size_t n, const char *restrict f, const struct tm *restrict tm)
{
nl_item item;
@@ -67,14 +93,15 @@ do_fmt:
fmt = "%Y-%m-%d";
goto recu_strftime;
case 'g':
- // FIXME
- val = 0; //week_based_year(tm)%100;
- fmt = "%02d";
- goto number;
case 'G':
- // FIXME
- val = 0; //week_based_year(tm);
fmt = "%04d";
+ val = tm->tm_year + 1900;
+ if (tm->tm_yday < 3 && week_num(tm) != 1) val--;
+ else if (tm->tm_yday > 360 && week_num(tm) == 1) val++;
+ if (*f=='g') {
+ fmt = "%02d";
+ val %= 100;
+ }
goto number;
case 'H':
val = tm->tm_hour;
@@ -133,27 +160,7 @@ do_fmt:
fmt = "%02d";
goto number;
case 'V':
- val = (tm->tm_yday + 7 - (tm->tm_wday+6)%7) / 7;
- /* If 1 Jan is just 1-3 days past Monday,
- * the previous week is also in this year. */
- if ((tm->tm_wday - tm->tm_yday - 2 + 371) % 7 <= 2)
- val++;
- if (!val) {
- val = 52;
- /* If 31 December of prev year a Thursday,
- * or Friday of a leap year, then the
- * prev year has 53 weeks. */
- int dec31 = (tm->tm_wday - tm->tm_yday - 1 + 7) % 7;
- if (dec31 == 4 || (dec31 == 5 && is_leap(tm->tm_year%400-1)))
- val++;
- } else if (val == 53) {
- /* If 1 January is not a Thursday, and not
- * a Wednesday of a leap year, then this
- * year has only 52 weeks. */
- int jan1 = (tm->tm_wday - tm->tm_yday + 371) % 7;
- if (jan1 != 4 && (jan1 != 3 || !is_leap(tm->tm_year)))
- val = 1;
- }
+ val = week_num(tm);
fmt = "%02d";
goto number;
case 'w':