date,touch: allow timezone offsets in dates
Allow ISO 8601 style dates to include a timezone offset. Like
the '@' format these dates aren't relative to the user's current
timezone and shouldn't be subject to DST adjustment.
- The implementation uses the strptime() '%z' format specifier.
This an extension which may not be available so the use of
timezones is a configuration option.
- The 'touch' applet has been updated to respect whether DST
adjustment is required, matching 'date'.
function old new delta
parse_datestr 624 730 +106
static.fmt_str 106 136 +30
touch_main 388 392 +4
date_main 818 819 +1
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/0 up/down: 141/0) Total: 141 bytes
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/libbb/Config.src b/libbb/Config.src
index f97de8e..58c5fad 100644
--- a/libbb/Config.src
+++ b/libbb/Config.src
@@ -395,3 +395,14 @@
default y
help
Support for printing infiniband addresses in network applets.
+
+config FEATURE_TIMEZONE
+ bool "Allow timezone in dates"
+ default y
+ depends on DESKTOP
+ help
+ Permit the use of timezones when parsing user-provided data
+ strings, e.g. '1996-04-09 12:45:00 -0500'.
+
+ This requires support for the '%z' extension to strptime() which
+ may not be available in all implementations.
diff --git a/libbb/time.c b/libbb/time.c
index 365b1df..41a69c7 100644
--- a/libbb/time.c
+++ b/libbb/time.c
@@ -8,7 +8,9 @@
*/
#include "libbb.h"
-void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm)
+/* Returns 0 if the time structure contains an absolute UTC time which
+ * should not be subject to DST adjustment by the caller. */
+int FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm)
{
char end = '\0';
#if ENABLE_DESKTOP
@@ -27,6 +29,10 @@
"%b %d %T %Y" "\0" /* month_name d HH:MM:SS YYYY */
"%Y-%m-%d %R" "\0" /* yyyy-mm-dd HH:MM */
"%Y-%m-%d %T" "\0" /* yyyy-mm-dd HH:MM:SS */
+#if ENABLE_FEATURE_TIMEZONE
+ "%Y-%m-%d %R %z" "\0" /* yyyy-mm-dd HH:MM TZ */
+ "%Y-%m-%d %T %z" "\0" /* yyyy-mm-dd HH:MM:SS TZ */
+#endif
"%Y-%m-%d %H" "\0" /* yyyy-mm-dd HH */
"%Y-%m-%d" "\0" /* yyyy-mm-dd */
/* extra NUL */;
@@ -38,8 +44,28 @@
fmt = fmt_str;
while (*fmt) {
endp = strptime(date_str, fmt, ptm);
- if (endp && *endp == '\0')
- return;
+ if (endp && *endp == '\0') {
+#if ENABLE_FEATURE_TIMEZONE
+ if (strchr(fmt, 'z')) {
+ time_t t;
+ struct tm *utm;
+
+ /* we have timezone offset: obtain Unix time_t */
+ ptm->tm_sec -= ptm->tm_gmtoff;
+ ptm->tm_isdst = 0;
+ t = timegm(ptm);
+ if (t == (time_t)-1)
+ break;
+ /* convert Unix time_t to struct tm in user's locale */
+ utm = localtime(&t);
+ if (!utm)
+ break;
+ *ptm = *utm;
+ return 0;
+ }
+#endif
+ return 1;
+ }
*ptm = save;
while (*++fmt)
continue;
@@ -124,7 +150,7 @@
struct tm *lt = localtime(&t);
if (lt) {
*ptm = *lt;
- return;
+ return 0;
}
}
end = '1';
@@ -241,6 +267,7 @@
if (end != '\0') {
bb_error_msg_and_die(bb_msg_invalid_date, date_str);
}
+ return 1;
}
time_t FAST_FUNC validate_tm_time(const char *date_str, struct tm *ptm)