view release on metacpan or  search on metacpan

unzip-6.0/timezone.c  view on Meta::CPAN

/*
  Copyright (c) 1990-2001 Info-ZIP.  All rights reserved.

  See the accompanying file LICENSE, version 2000-Apr-09 or later
  (the contents of which are also included in zip.h) for terms of use.
  If, for some reason, all these files are missing, the Info-ZIP license
  also may be found at:  ftp://ftp.info-zip.org/pub/infozip/license.html
*/
/* Replacement time library functions, based on platform independent public
 * domain timezone code from ftp://elsie.nci.nih.gov/pub, with mktime and
 * mkgmtime from our own mktime.c in Zip.
 *
 * Contains:  tzset()
 *            __tzset()
 *            gmtime()
 *            localtime()
 *            mktime()
 *            mkgmtime()
 *            GetPlatformLocalTimezone()  [different versions]
 */

/* HISTORY/CHANGES
 * 17 Jun 00, Paul Kienitz, added the PD-based tzset(), localtime(), and so on
 *            to amiga/filedate.c, replacing GNU-based functions which had
 *            replaced time_lib.c, both having been rejected for licensing
 *            reasons.  Support for timezone files and leap seconds was removed.
 *
 * 23 Aug 00, Paul Kienitz, split into separate timezone.c file, made platform
 *            independent, copied in mktime() and mkgmtime() from Zip, renamed
 *            locale_TZ as GetPlatformLocalTimezone(), for use as a generic
 *            hook by other platforms.
 */

#ifndef __timezone_c
#define __timezone_c


#include "zip.h"
#include "timezone.h"
#include <ctype.h>
#include <errno.h>

#ifdef IZTZ_DEFINESTDGLOBALS
long timezone = 0;
int daylight = 0;
char *tzname[2];
#endif

#ifndef IZTZ_GETLOCALETZINFO
#  define IZTZ_GETLOCALETZINFO(ptzstruct, pgenrulefunct) (FALSE)
#endif

int real_timezone_is_set = FALSE;       /* set by tzset() */


#define TZDEFRULESTRING ",M4.1.0,M10.5.0"
#define TZDEFAULT       "EST5EDT"

#define SECSPERMIN      60
#define MINSPERHOUR     60
#define HOURSPERDAY     24
#define DAYSPERWEEK     7
#define DAYSPERNYEAR    365
#define DAYSPERLYEAR    366
#define SECSPERHOUR     (SECSPERMIN * MINSPERHOUR)
#define SECSPERDAY      ((long) SECSPERHOUR * HOURSPERDAY)
#define MONSPERYEAR 12

#define EPOCH_WDAY      4     /* Jan 1, 1970 was thursday */
#define EPOCH_YEAR      1970
#define TM_YEAR_BASE    1900
#define FIRST_GOOD_YEAR ((time_t) -1 < (time_t) 1 ? EPOCH_YEAR-68 : EPOCH_YEAR)
#define LAST_GOOD_YEAR  (EPOCH_YEAR + ((time_t) -1 < (time_t) 1 ? 67 : 135))

#define YDAYS(month, year) yr_days[leap(year)][month]

/* Nonzero if `y' is a leap year, else zero. */
#define leap(y)  (((y) % 4 == 0 && (y) % 100 != 0) || (y) % 400 == 0)

/* Number of leap years from EPOCH_YEAR  to `y' (not including `y' itself). */
#define _P4      ((EPOCH_YEAR / 4) * 4 + 1)
#define _P100    ((EPOCH_YEAR / 100) * 100 + 1)
#define _P400    ((EPOCH_YEAR / 400) * 400 + 1)
#define nleap(y) (((y) - _P4) / 4 - ((y) - _P100) / 100 + ((y) - _P400) / 400)

/* Length of month `m' (0 .. 11) */
#define monthlen(m, y) (yr_days[0][(m)+1] - yr_days[0][m] + \
                        ((m) == 1 && leap(y)))

/* internal module-level constants */