why does strptime (c++) seem to not correctly parse date/time string????

lxvor · 02-08-2010, 03:15 PM

so I'll come right to the point. here is the problem code using strptime() function.

==================
#include <stdio.h>
#include <string.h>
#include <time.h>

int main()
{
memset(&tm_obj, 0 , sizeof(tm_obj));
strptime("2009-12-24T9:47:06", "%Y-%m-%dT%H:%M:%S", &tm_obj);

printf("year: %d\n", tm_obj.tm_year);
printf("month: %d\n", tm_obj.tm_mon);
printf("day: %d\n", tm_obj.tm_mday);
printf("hour: %d\n", tm_obj.tm_hour);
printf("min: %d\n", tm_obj.tm_min);
printf("sec: %d\n", tm_obj.tm_sec);
return 0;
}
output:
-----------
year: 109
month: 11
day: 24
hour: 9
min: 47
sec: 6
===================

Why are the Month and Year so messed up?? I am using strptime() according to the man page. Does anyone have a clue.

I would really appreciate if somebody could explain this to me.

Thanks.

nadroj · 02-08-2010, 03:23 PM

Ive never used any of these functinons. However, a quick look at a man page of the function seems that strptime creates a time structure, from the given string representation of a time. However, the time struct it creates is still not useful to directly extract the day, etc, out of it. It seems there is another function strftime that has similar specifiers to extract the necessary information and put it in a buffer.

The man page I saw was this: http://linux.about.com/library/cmd/blcmdl3_strptime.htm. See the "Example" section, for both creation of the struct and extracting fields from it.

David1357 · 02-08-2010, 05:08 PM

Quote:

Originally Posted by lxvor

Why are the Month and Year so messed up?

The month and year are correct. Here is the definition of "struct tm" from the man page for "localtime":

Code:

       Broken-down time is stored in the structure tm which is
       defined in <time.h> as follows:

              struct tm {
                  int tm_sec;         /* seconds */
                  int tm_min;         /* minutes */
                  int tm_hour;        /* hours */
                  int tm_mday;        /* day of the month */
                  int tm_mon;         /* month */
                  int tm_year;        /* year */
                  int tm_wday;        /* day of the week */
                  int tm_yday;        /* day in the year */
                  int tm_isdst;       /* daylight saving time */
              };

       The members of the tm structure are:

       tm_sec The number of seconds after the minute, normally in the
       range 0 to 59, but can be up to 60 to allow for leap seconds.

       tm_min The number of minutes after the hour, in the range 0 to
       59.

       tm_hour
              The number of hours past midnight, in the range 0 to 23.

       tm_mday
              The day of the month, in the range 1 to 31.

       tm_mon The number of months since January, in the range 0 to 11.

       tm_year
              The number of years since 1900.

       tm_wday
              The number of days since Sunday, in the range 0 to 6.

       tm_yday
              The number of days since January 1, in the range 0 to 365.

       tm_isdst
              A  flag that indicates whether daylight saving time is in
              effect at the time described.  The value is positive if
              daylight saving time is in effect, zero if it is not, and
              negative if the information is not available.

Note that "tm_mon" is in the range 0 to 11 inclusive (Thus the month 11 in your output) and that "tm_year" starts at 1900 (Thus the year 109 in your output).