the scenario is: I get datetime in format "YYYY-MM-DD HH:MM:SS" with libexif. To minimize the saving cost, I wanna convert the datetime to unix timestamp or alike which only cost 64bit or 32bit. Is there any explicit way with c?
+2
A:
Convert each part of the date/time into an integer to populate a struct tm, then convert that into a time_t using mktime.
Mark Ransom
2009-06-16 16:33:29
+10
A:
You could try a combination of strptime and mktime
struct tm tm;
time_t epoch;
if ( strptime(timestamp, "%Y-%m-%d %H:%M:%S", &tm) != NULL )
epoch = mktime(&tm);
else
// badness
Kjetil Jorgensen
2009-06-16 16:35:28
I knew there had to be something like strptime, but I couldn't find it. I use Microsoft 99% of the time, and they don't support it.
Mark Ransom
2009-06-16 16:40:44
+1: I was thinking of strptime, but I couldn't remember the function name for it.
R. Bemrose
2009-06-16 16:42:17
As a side note, if you're using Windows, see this question: http://stackoverflow.com/questions/321849/strptime-equivalent-on-windows
R. Bemrose
2009-06-16 16:44:43
A:
Here is a wired solution in c/pseudo code I just hacked together. Good luck!
char * runner = NULL;
char *string_orig = "YYYY-MM-DD HH:MM:SS";
time_t time = 0;
struct tm tmp;
use strstr(string_orig, "-") and atoi foreach
tmp->tm_year ..
tmp->tm_mon ..
tmp->tm_mday ..
tmp->tm_hour ..
tmp->tm_min ..
tmp->tm_sec ..
with *runner as help
time = mktime(&tm)
merkuro
2009-06-16 16:38:35