년월일시분초 C버전

#include 
#include 
#include 
#include 

int main() {
  char buffer[26];
  int millisec;
  struct tm* tm_info;
  struct timeval tv;

  gettimeofday(&tv, NULL);

  millisec = lrint(tv.tv_usec/1000.0); // Round to nearest millisec
  if (millisec>=1000) { // Allow for rounding up to nearest second
    millisec -=1000;
    tv.tv_sec++;
  }

  tm_info = localtime(&tv.tv_sec);

  strftime(buffer, 26, "%Y:%m:%d %H:%M:%S", tm_info);
  printf("%s.%03d\n", buffer, millisec);

  return 0;
}