fusl/src/time/__asctime.c

#include <time.h>
#include <stdio.h>
#include <langinfo.h>
#include "atomic.h"

const char* __nl_langinfo(nl_item);

char* __asctime(const struct tm* restrict tm, char* restrict buf) {
  /* FIXME: change __nl_langinfo to __nl_langinfo_l with explicit C
   * locale once we have locales */
  if (snprintf(buf, 26, "%.3s %.3s%3d %.2d:%.2d:%.2d %d\n",
               __nl_langinfo(ABDAY_1 + tm->tm_wday),
               __nl_langinfo(ABMON_1 + tm->tm_mon), tm->tm_mday, tm->tm_hour,
               tm->tm_min, tm->tm_sec, 1900 + tm->tm_year) >= 26) {
    /* ISO C requires us to use the above format string,
     * even if it will not fit in the buffer. Thus asctime_r
     * is _supposed_ to crash if the fields in tm are too large.
     * We follow this behavior and crash "gracefully" to warn
     * application developers that they may not be so lucky
     * on other implementations (e.g. stack smashing..).
     */
    a_crash();
  }
  return buf;
}