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>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 7d6ab4a93..1ec8d2d3b 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -690,7 +690,7 @@ struct BUG_too_small {
 };
 
 
-void parse_datestr(const char *date_str, struct tm *ptm) FAST_FUNC;
+int parse_datestr(const char *date_str, struct tm *ptm) FAST_FUNC;
 time_t validate_tm_time(const char *date_str, struct tm *ptm) FAST_FUNC;
 char *strftime_HHMMSS(char *buf, unsigned len, time_t *tp) FAST_FUNC;
 char *strftime_YYYYMMDDHHMMSS(char *buf, unsigned len, time_t *tp) FAST_FUNC;