src/libstddjb/localtm_from_ltm64.c


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/* ISC license. */

#include <skalibs/sysdeps.h>
#include <skalibs/bsdsnowflake.h>
#include <errno.h>
#include <time.h>
#include <skalibs/uint64.h>
#include <skalibs/tai.h>
#include <skalibs/djbtime.h>

int localtm_from_ltm64 (struct tm *l, uint64_t uu, int tzh)
{
  time_t u ;
  if (uu < TAI_MAGIC) return (errno = EINVAL, 0) ;
  uu -= TAI_MAGIC ;
#if SKALIBS_SIZEOFTIME != 8
  if (uu > 0xFFFFFFFFUL) return (errno = EOVERFLOW, 0) ;
#endif
  u = (time_t)uu - !!(tzh & 2) ;
  if (tzh & 1 ? !localtime_r(&u, l) : !gmtime_r(&u, l)) return 0 ;
  if (tzh & 2) l->tm_sec++ ;
  return 1 ;
}