Mine

void trace_out(const char *fmt, ... ) {  static FILE *trace_file = 0L;  time_t now = time(0L);  char date_string[23];  strftime(date_string, 256, "%Y-%m-%d %H.%M.%S", localtime(&now));  if (!trace_file) {    trace_file = fopen("trace.txt", "a+");    if (!trace_file)      return;  }  va_list v;  va_start(v, fmt);  fprintf(trace_file, "%s |", date_string);  vfprintf(trace_file, fmt, v);  fputc('\n', trace_file);  fflush(trace_file);}