emo/busybox
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

date,touch: allow timezone offsets in dates

Browse Source 
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>
This commit is contained in:
Ron Yorston
2021-09-16 10:26:14 +01:00
committed by Denys Vlasenko
parent 83e20cb81c
commit 9fe1548bbf
6 changed files with 83 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
libbb/Config.src
View File

@@ -395,3 +395,14 @@ config FEATURE_HWIB
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.

35
libbb/time.c
View File

@@ -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 @@ void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm)
"%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 @@ void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm)
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 @@ void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm)
struct tm *lt = localtime(&t);
if (lt) {
*ptm = *lt;
return;
return 0;
}
}
end = '1';
@@ -241,6 +267,7 @@ void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm)
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)