localtime.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 76 行

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

#include "sys/timefcns.h"

struct tm *
localtime(const time_t * ptime)
{
  struct tm *ptm;
  long ltime;

  if ((long) *ptime < 0L)
    return (NULL);

  tzset();

  if ((*ptime > 3 * _DAY_SEC) && (*ptime < LONG_MAX - 3 * _DAY_SEC)) {
    ltime = (long) *ptime - _timezone;
    ptm = gmtime((time_t *) & ltime);

    if (_daylight && _isindst(ptm)) {
      ltime -= _dstbias;
      ptm = gmtime((time_t *) & ltime);
      ptm->tm_isdst = 1;
    }
  } else {
    ptm = gmtime(ptime);

    if (_isindst(ptm))
      ltime = (long) ptm->tm_sec - (_timezone + _dstbias);
    else
      ltime = (long) ptm->tm_sec - _timezone;
    ptm->tm_sec = (int) (ltime % 60);
    if (ptm->tm_sec < 0) {
      ptm->tm_sec += 60;
      ltime -= 60;
    }

    ltime = (long) ptm->tm_min + ltime / 60;
    ptm->tm_min = (int) (ltime % 60);
    if (ptm->tm_min < 0) {
      ptm->tm_min += 60;
      ltime -= 60;
    }

    ltime = (long) ptm->tm_hour + ltime / 60;
    ptm->tm_hour = (int) (ltime % 24);
    if (ptm->tm_hour < 0) {
      ptm->tm_hour += 24;
      ltime -= 24;
    }

    ltime /= 24;

    if (ltime > 0L) {
      ptm->tm_wday = (ptm->tm_wday + ltime) % 7;
      ptm->tm_mday += ltime;
      ptm->tm_yday += ltime;
    } else if (ltime < 0L) {
      ptm->tm_wday = (ptm->tm_wday + 7 + ltime) % 7;
      if ((ptm->tm_mday += ltime) <= 0) {
        ptm->tm_mday += 31;
        ptm->tm_yday = 364;
        ptm->tm_mon = 11;
        ptm->tm_year--;
      } else {
        ptm->tm_yday += ltime;
      }
    }
  }


  return (ptm);
}