C语言库mktime()函数

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

int main () {
   int ret;
   struct tm info;
   char buffer[80];

   info.tm_year = 2001 - 1900;
   info.tm_mon = 7 - 1;
   info.tm_mday = 4;
   info.tm_hour = 0;
   info.tm_min = 0;
   info.tm_sec = 1;
   info.tm_isdst = -1;

   ret = mktime(&info);
   if( ret == -1 ) {
      printf(Error: unable to make time using mktime\n);
   } else {
      strftime(buffer, sizeof(buffer), %c, &info );
      printf(buffer);
   }

   return(0);
}