strbuf: let strbuf_addftime handle %z and %Z itself
There is no portable way to pass timezone information to strftime. Add parameters for timezone offset and name to strbuf_addftime and let it handle the timezone-related format specifiers %z and %Z internally. Callers can opt out for %Z by passing NULL as timezone name. %z is always handled internally -- this helps on Windows, where strftime would expand it to a timezone name (same as %Z), in violation of POSIX. Modifiers are not handled, e.g. %Ez is still passed to strftime. Use an empty string as timezone name in show_date (the only current caller) for now because we only have the timezone offset in non-local mode. POSIX allows %Z to resolve to an empty string in case of missing information. Helped-by: Ulrich Mueller <ulm@gentoo.org> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
René Scharfe committed
Jun 15, 2017 at 14:29 UTC
c3fbf81a8534cf88ff948d12004eb94929ec1174
5 files changed
+54
-8
Documentation/rev-list-options.txt
+2
-1
@@ -764,7 +764,8 @@ timezone value.
764
1970). As with `--raw`, this is always in UTC and therefore `-local`
765
has no effect.
766
+
767
-`--date=format:...` feeds the format `...` to your system `strftime`.
767
+`--date=format:...` feeds the format `...` to your system `strftime`,
768
+except for %z and %Z, which are handled internally.
769
Use `--date=format:%c` to show the date in your system locale's
770
preferred format. See the `strftime` manual for a complete list of
771
format placeholders. When using `-local`, the correct syntax is
date.c
+1
-1
@@ -233,7 +233,7 @@ const char *show_date(unsigned long time, int tz, const struct date_mode *mode)
233
month_names[tm->tm_mon], tm->tm_year + 1900,
234
tm->tm_hour, tm->tm_min, tm->tm_sec, tz);
235
else if (mode->type == DATE_STRFTIME)
236
- strbuf_addftime(&timebuf, mode->strftime_fmt, tm);
236
+ strbuf_addftime(&timebuf, mode->strftime_fmt, tm, tz, "");
237
else
238
strbuf_addf(&timebuf, "%.3s %.3s %d %02d:%02d:%02d %d%c%+05d",
239
weekday_names[tm->tm_wday],
strbuf.c
+37
-4
@@ -785,14 +785,48 @@ char *xstrfmt(const char *fmt, ...)
785
return ret;
786
}
787
788
-void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm)
788
+void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm,
789
+ int tz_offset, const char *tz_name)
790
{
791
+ struct strbuf munged_fmt = STRBUF_INIT;
792
size_t hint = 128;
793
size_t len;
794
795
if (!*fmt)
796
return;
797
798
+ /*
799
+ * There is no portable way to pass timezone information to
800
+ * strftime, so we handle %z and %Z here.
801
+ */
802
+ for (;;) {
803
+ const char *percent = strchrnul(fmt, '%');
804
+ strbuf_add(&munged_fmt, fmt, percent - fmt);
805
+ if (!*percent)
806
+ break;
807
+ fmt = percent + 1;
808
+ switch (*fmt) {
809
+ case '%':
810
+ strbuf_addstr(&munged_fmt, "%%");
811
+ fmt++;
812
+ break;
813
+ case 'z':
814
+ strbuf_addf(&munged_fmt, "%+05d", tz_offset);
815
+ fmt++;
816
+ break;
817
+ case 'Z':
818
+ if (tz_name) {
819
+ strbuf_addstr(&munged_fmt, tz_name);
820
+ fmt++;
821
+ break;
822
+ }
823
+ /* FALLTHROUGH */
824
+ default:
825
+ strbuf_addch(&munged_fmt, '%');
826
+ }
827
+ }
828
+ fmt = munged_fmt.buf;
829
+
830
strbuf_grow(sb, hint);
831
len = strftime(sb->buf + sb->len, sb->alloc - sb->len, fmt, tm);
832
@@ -804,17 +838,16 @@ void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm)
838
* output contains at least one character, and then drop the extra
839
* character before returning.
840
*/
807
- struct strbuf munged_fmt = STRBUF_INIT;
808
- strbuf_addf(&munged_fmt, "%s ", fmt);
841
+ strbuf_addch(&munged_fmt, ' ');
842
while (!len) {
843
hint *= 2;
844
strbuf_grow(sb, hint);
845
len = strftime(sb->buf + sb->len, sb->alloc - sb->len,
846
munged_fmt.buf, tm);
847
}
815
- strbuf_release(&munged_fmt);
848
len--; /* drop munged space */
849
}
850
+ strbuf_release(&munged_fmt);
851
strbuf_setlen(sb, sb->len + len);
852
}
853
strbuf.h
+8
-2
@@ -340,8 +340,14 @@ extern void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap);
340
341
/**
342
* Add the time specified by `tm`, as formatted by `strftime`.
343
- */
344
-extern void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm);
343
+ * `tz_name` is used to expand %Z internally unless it's NULL.
344
+ * `tz_offset` is in decimal hhmm format, e.g. -600 means six hours west
345
+ * of Greenwich, and it's used to expand %z internally. However, tokens
346
+ * with modifiers (e.g. %Ez) are passed to `strftime`.
347
+ */
348
+extern void strbuf_addftime(struct strbuf *sb, const char *fmt,
349
+ const struct tm *tm, int tz_offset,
350
+ const char *tz_name);
351
352
/**
353
* Read a given size of data from a FILE* pointer to the buffer.
t/t0006-date.sh
+6
@@ -51,6 +51,12 @@ check_show iso-local "$TIME" '2016-06-15 14:13:20 +0000'
51
check_show raw-local "$TIME" '1466000000 +0000'
52
check_show unix-local "$TIME" '1466000000'
53
54
+check_show 'format:%z' "$TIME" '+0200'
55
+check_show 'format-local:%z' "$TIME" '+0000'
56
+check_show 'format:%Z' "$TIME" ''
57
+check_show 'format:%%z' "$TIME" '%z'
58
+check_show 'format-local:%%z' "$TIME" '%z'
59
+
60
# arbitrary time absurdly far in the future
61
FUTURE="5758122296 -0400"
62
check_show iso "$FUTURE" "2152-06-19 18:24:56 -0400" LONG_IS_64BIT