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authorJim Meyering <jim@meyering.net>1996-04-08 04:53:54 +0000
committerJim Meyering <jim@meyering.net>1996-04-08 04:53:54 +0000
commit4da76e0c6fc47da53fd84ffaf844f4abfefeade4 (patch)
tree5e1449add031645b1f894e1517beacd07e552c34 /lib
parent39c92b4dc4dd9719a9d8afaffcfcf18ff2d47cca (diff)
downloadcoreutils-4da76e0c6fc47da53fd84ffaf844f4abfefeade4.tar.xz
(mon_week_ISO): New function to implement new %V format.
(sun_week): Make TM parameter `const'. (mon_week): Likewise. (mon_week): Rewrite to correctly implement %W format..
Diffstat (limited to 'lib')
-rw-r--r--lib/strftime.c58
1 files changed, 44 insertions, 14 deletions
diff --git a/lib/strftime.c b/lib/strftime.c
index 5cf5f0d17..2b8f3600d 100644
--- a/lib/strftime.c
+++ b/lib/strftime.c
@@ -67,6 +67,7 @@
%j day of year (001..366)
%m month (01..12)
%U week number of year with Sunday as first day of week (00..53)
+ %V FIXME
%w day of week (0..6)
%W week number of year with Monday as first day of week (00..53)
%x locale's date representation (mm/dd/yy)
@@ -233,38 +234,63 @@ add_num_tz (string, max, minutes_east)
return length;
}
-/* Return the week in the year of the time in TM, with the weeks
- starting on Sundays. */
+/* Implement %U. Return the week in the year of the time in TM,
+ with the weeks starting on Sundays. */
static int
sun_week (tm)
- struct tm *tm;
+ const struct tm *tm;
{
int dl;
/* %U Week of the year (Sunday as the first day of the week) as a decimal
- number [00-53]. All days in a new year preceding the first Sunday are
+ number [00-53]. All days in a new year preceding the first Sunday are
considered to be in week 0. */
dl = tm->tm_yday - tm->tm_wday;
return dl < 0 ? 0 : dl / 7 + 1;
}
-/* Return the week in the year of the time in TM, with the weeks
- starting on Mondays. */
+/* Implement %V. Similar to mon_week (%W), but there is no 0'th week --
+ they're numbered [01-53]. And if the week containing January 1 has
+ four or more days in the new year, then it is considered week 1;
+ otherwise, it is week 53 of the previous year, and the next week is
+ week 1. (See the ISO 8601: 1988 standard.) */
+
+static int
+mon_week_ISO (tm)
+ const struct tm *tm;
+{
+ int dl, n_days_before_first_monday;
+ int week_num;
+
+ n_days_before_first_monday = (tm->tm_yday + 7 - tm->tm_wday + 1) % 7;
+ dl = tm->tm_yday - n_days_before_first_monday;
+ week_num = dl < 0 ? 0 : dl / 7 + 1;
+ if (n_days_before_first_monday >= 4)
+ {
+ week_num = (week_num + 1) % 54;
+ if (week_num == 0)
+ week_num = 1;
+ }
+ if (week_num == 0)
+ week_num = 53;
+
+ return week_num;
+}
+
+/* Implement %W. Return the week in the year of the time in TM,
+ with the weeks starting on Mondays. */
static int
mon_week (tm)
- struct tm *tm;
+ const struct tm *tm;
{
- int dl, wday;
+ int dl, n_days_before_first_monday;
- if (tm->tm_wday == 0)
- wday = 6;
- else
- wday = tm->tm_wday - 1;
- dl = tm->tm_yday - wday;
- return dl <= 0 ? 0 : dl / 7 + (dl % 7 != 0);
+ n_days_before_first_monday = (tm->tm_yday + 7 - tm->tm_wday + 1) % 7;
+ dl = tm->tm_yday - n_days_before_first_monday;
+ return dl < 0 ? 0 : dl / 7 + 1;
}
#if !defined(HAVE_TM_ZONE) && !defined(HAVE_TZNAME)
@@ -499,6 +525,10 @@ strftime (string, max, format, tm)
length +=
add_num2 (&string[length], sun_week (tm), max - length, pad);
break;
+ case 'V':
+ length += add_num2 (&string[length], mon_week_ISO (tm),
+ max - length, pad);
+ break;
case 'w':
add_char (tm->tm_wday + '0');
break;