touch: implement -d --date (our own testsuite needs that)

function                                             old     new   delta
static.uname_longopts                                  -     137    +137
touch_main                                           231     360    +129
static.touch_longopts                                  -      32     +32
validate_tm_time                                       -      28     +28
packed_usage                                       26616   26624      +8
date_main                                            687     686      -1
static.longopts                                      162       -    -162
------------------------------------------------------------------------------
(add/remove: 3/1 grow/shrink: 2/1 up/down: 334/-163)          Total: 171 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/libbb/time.c b/libbb/time.c
index 30b760f71..1cf2a050e 100644
--- a/libbb/time.c
+++ b/libbb/time.c
@@ -71,6 +71,15 @@ void FAST_FUNC parse_datestr(const char *date_str, struct tm *tm_time)
         }
 }
 
+time_t FAST_FUNC validate_tm_time(const char *date_str, struct tm *tm_time)
+{
+        time_t t = mktime(tm_time);
+        if (t == (time_t) -1L) {
+                bb_error_msg_and_die(bb_msg_invalid_date, date_str);
+        }
+        return t;
+}
+
 #if ENABLE_MONOTONIC_SYSCALL
 
 #include <sys/syscall.h>