strftime_bug.c

#include <time.h>
#include <string.h>
#include <errno.h>

#define LOGGER_TIME_SIZE    16

int main() {
  time_t clock;
  struct tm lt;
  char formatted_time_[LOGGER_TIME_SIZE];

  time(&clock);
  localtime_r(&clock, &lt);

  strftime(formatted_time_, LOGGER_TIME_SIZE, "%b %e %H:%M:%S", &lt);

  return errno; // returns EINVAL, 22 which is set by strftime
}