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 by passing NULL as timezone name.
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 nothing in case of missing info.
Helped-by: Ulrich Mueller <ulm@xxxxxxxxxx>
Helped-by: Jeff King <peff@xxxxxxxx>
Signed-off-by: Rene Scharfe <l.s.r@xxxxxx>
---
Duplicates strbuf_expand to a certain extent, but not too badly, I
think. Leaves the door open for letting strftime handle the local
case.
date.c | 2 +-
strbuf.c | 42 ++++++++++++++++++++++++++++++++++++++----
strbuf.h | 11 ++++++++---
t/t6006-rev-list-format.sh | 12 ++++++++++++
4 files changed, 59 insertions(+), 8 deletions(-)
diff --git a/date.c b/date.c
index 63fa99685e..5580577334 100644
--- a/date.c
+++ b/date.c
@@ -246,7 +246,7 @@ const char *show_date(timestamp_t time, int tz, const struct date_mode *mode)
month_names[tm->tm_mon], tm->tm_year + 1900,
tm->tm_hour, tm->tm_min, tm->tm_sec, tz);
else if (mode->type == DATE_STRFTIME)
- strbuf_addftime(&timebuf, mode->strftime_fmt, tm);
+ strbuf_addftime(&timebuf, mode->strftime_fmt, tm, tz, "");
else
strbuf_addf(&timebuf, "%.3s %.3s %d %02d:%02d:%02d %d%c%+05d",
weekday_names[tm->tm_wday],
diff --git a/strbuf.c b/strbuf.c
index 00457940cf..b880107370 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -785,14 +785,47 @@ char *xstrfmt(const char *fmt, ...)
return ret;
}
-void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm)
+void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm,
+ int tz_offset, const char *tz_name)
{
+ struct strbuf munged_fmt = STRBUF_INIT;
size_t hint = 128;
size_t len;
if (!*fmt)
return;
+ /*
+ * There is no portable way to pass timezone information to
+ * strftime, so we handle %z and %Z here.
+ */
+ if (tz_name) {
+ for (;;) {
+ const char *percent = strchrnul(fmt, '%');
+ strbuf_add(&munged_fmt, fmt, percent - fmt);
+ if (!*percent)
+ break;
+ fmt = percent + 1;
+ switch (*fmt) {
+ case '%':
+ strbuf_addstr(&munged_fmt, "%%");
+ fmt++;
+ break;
+ case 'z':
+ strbuf_addf(&munged_fmt, "%+05d", tz_offset);
+ fmt++;
+ break;
+ case 'Z':
+ strbuf_addstr(&munged_fmt, tz_name);
+ fmt++;
+ break;
+ default:
+ strbuf_addch(&munged_fmt, '%');
+ }
+ }
+ fmt = munged_fmt.buf;
+ }
+
strbuf_grow(sb, hint);
len = strftime(sb->buf + sb->len, sb->alloc - sb->len, fmt, tm);
@@ -804,17 +837,18 @@ void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm)
* output contains at least one character, and then drop the extra
* character before returning.
*/
- struct strbuf munged_fmt = STRBUF_INIT;
- strbuf_addf(&munged_fmt, "%s ", fmt);
+ if (fmt != munged_fmt.buf)
+ strbuf_addstr(&munged_fmt, fmt);
+ strbuf_addch(&munged_fmt, ' ');
while (!len) {
hint *= 2;
strbuf_grow(sb, hint);
len = strftime(sb->buf + sb->len, sb->alloc - sb->len,
munged_fmt.buf, tm);
}
- strbuf_release(&munged_fmt);
len--; /* drop munged space */
}
+ strbuf_release(&munged_fmt);
strbuf_setlen(sb, sb->len + len);
}
diff --git a/strbuf.h b/strbuf.h
index 80047b1bb7..39d5836abd 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -339,9 +339,14 @@ __attribute__((format (printf,2,0)))
extern void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap);
/**
- * Add the time specified by `tm`, as formatted by `strftime`.
- */
-extern void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm);
+ * Add the time specified by `tm`, as formatted by `strftime`. `tz_offset`
+ * and `tz_name` are used to expand %z and %Z internally, unless `tz_name`
+ * is NULL. `tz_offset` is in decimal hhmm format, e.g. -600 means six
+ * hours west of Greenwich.
+ */
+extern void strbuf_addftime(struct strbuf *sb, const char *fmt,
+ const struct tm *tm, int tz_offset,
+ const char *tz_name);
/**
* Read a given size of data from a FILE* pointer to the buffer.
diff --git a/t/t6006-rev-list-format.sh b/t/t6006-rev-list-format.sh
index a1dcdb81d7..dc0bed8d90 100755
--- a/t/t6006-rev-list-format.sh
+++ b/t/t6006-rev-list-format.sh
@@ -483,4 +483,16 @@ test_expect_success 'unused %G placeholders are passed through' '
test_cmp expect actual
'
+test_expect_success 'date format "%F %T %z" is the same as iso' '
+ git log -1 --format="%ad" --date=iso >expect &&
+ git log -1 --format="%ad" --date="format:%F %T %z" >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'date format "%%z" expands to percent zed' '
+ echo "%z" >expect &&
+ git log -1 --format="%ad" --date="format:%%z" >actual &&
+ test_cmp expect actual
+'
+
test_done
--
2.13.0