gmtime.c

来自「俄罗斯高人Mamaich的Pocket gcc编译器（运行在PocketPC上）」· C语言 代码 · 共 66 行

#include <stdlib.h>
#include <time.h>

#include "sys/timefcns.h"

static struct tm tb = { 0 };

struct tm *
gmtime(const time_t * timp)
{
  long caltim = *timp;
  int islpyr = 0;
  int tmptim;
  int *mdays;

  struct tm *ptb = &tb;

  if (caltim < 0L)
    return (NULL);

  tmptim = (int) (caltim / _FOUR_YEAR_SEC);
  caltim -= ((long) tmptim * _FOUR_YEAR_SEC);

  tmptim = (tmptim * 4) + 70;

  if (caltim >= _YEAR_SEC) {
    tmptim++;
    caltim -= _YEAR_SEC;

    if (caltim >= _YEAR_SEC) {
      tmptim++;
      caltim -= _YEAR_SEC;

      if (caltim >= (_YEAR_SEC + _DAY_SEC)) {
        tmptim++;
        caltim -= (_YEAR_SEC + _DAY_SEC);
      } else {
        islpyr++;
      }
    }
  }

  ptb->tm_year = tmptim;

  ptb->tm_yday = (int) (caltim / _DAY_SEC);
  caltim -= (long) (ptb->tm_yday) * _DAY_SEC;

  if (islpyr)
    mdays = _lpdays;
  else
    mdays = _days;

  for (tmptim = 1; mdays[tmptim] < ptb->tm_yday; tmptim++);

  ptb->tm_mon = --tmptim;
  ptb->tm_mday = ptb->tm_yday - mdays[tmptim];
  ptb->tm_wday = ((int) (*timp / _DAY_SEC) + _BASE_DOW) % 7;
  ptb->tm_hour = (int) (caltim / 3600);
  caltim -= (long) ptb->tm_hour * 3600L;
  ptb->tm_min = (int) (caltim / 60);
  ptb->tm_sec = (int) (caltim - (ptb->tm_min) * 60);
  ptb->tm_isdst = 0;

  return ((struct tm *) ptb);
}