/* Convert struct partime into time_t.  */ /* Copyright 1992, 1993, 1994, 1995, 1997 Paul Eggert   Distributed under license by the Free Software Foundation, Inc.    This file is part of RCS.    RCS is free software; you can redistribute it and/or modify   it under the terms of the GNU General Public License as published by   the Free Software Foundation; either version 2, or (at your option)   any later version.    RCS is distributed in the hope that it will be useful,   but WITHOUT ANY WARRANTY; without even the implied warranty of   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the   GNU General Public License for more details.    You should have received a copy of the GNU General Public License   along with RCS; see the file COPYING.   If not, write to the Free Software Foundation,   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.    Report problems and direct all questions to: 	rcs-bugs@cs.purdue.edu  */ #if has_conf_h# include <conf.h>#else# if HAVE_CONFIG_H#  include <config.h># else#  ifndef __STDC__#   define const#  endif# endif  /* MIPS RISCOS4.52 defines time_t in <sys/types.h> not <time.h>.  */# include <sys/types.h># if HAVE_LIMITS_H#  include <limits.h># endif# ifndef LONG_MIN# define LONG_MIN (-1-2147483647L)# endif# if STDC_HEADERS#  include <stdlib.h># endif# include <time.h># ifdef __STDC__#  define P(x) x# else#  define P(x) ()# endif#endif #include <partime.h>#include <maketime.h> char const maketId[] =  "$Id: maketime.c,v 5.15 1997/06/17 16:54:36 eggert Exp $"; static int isleap P ((int));static int month_days P ((struct tm const *));static time_t maketime P ((struct partime const *, time_t)); /* For maximum portability, use only localtime and gmtime.   Make no assumptions about the time_t epoch or the range of time_t values.   Avoid mktime because it's not universal and because there's no easy,   portable way for mktime to yield the inverse of gmtime.  */ #define TM_YEAR_ORIGIN 1900 static intisleap (y)     int y;{  return (y & 3) == 0 && (y % 100 != 0 || y % 400 == 0);} /* days in year before start of months 0-12 */static int const month_yday[] ={  0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365}; /* Yield the number of days in TM's month.  */static intmonth_days (tm)     struct tm const *tm;{  int m = tm->tm_mon;  return (month_yday[m + 1] - month_yday[m]	  + (m == 1 && isleap (tm->tm_year + TM_YEAR_ORIGIN)));} /* Convert UNIXTIME to struct tm form.   Use gmtime if available and if !LOCALZONE, localtime otherwise.  */struct tm *time2tm (unixtime, localzone)     time_t unixtime;     int localzone;{  struct tm *tm;#ifdef TZ_is_unset  static char const *TZ;  if (!TZ && !(TZ = getenv ("TZ")))    TZ_is_unset ("The TZ environment variable is not set; please set it to your timezone");#endif  if (localzone || !(tm = gmtime (&unixtime)))    tm = localtime (&unixtime);  return tm;} /* Yield A - B, measured in seconds.  */time_tdifftm (a, b)     struct tm const *a;     struct tm const *b;{  int ay = a->tm_year + (TM_YEAR_ORIGIN - 1);  int by = b->tm_year + (TM_YEAR_ORIGIN - 1);  int ac = ay / 100 - (ay % 100 < 0);  int bc = by / 100 - (by % 100 < 0);  int difference_in_day_of_year = a->tm_yday - b->tm_yday;  int intervening_leap_days = (((ay >> 2) - (by >> 2))			       - (ac - bc)			       + ((ac >> 2) - (bc >> 2)));  time_t difference_in_years = ay - by;  time_t difference_in_days    = (difference_in_years * 365       + (intervening_leap_days + difference_in_day_of_year));  return (((((difference_in_days * 24	      + (a->tm_hour - b->tm_hour))	     * 60)	    + (a->tm_min - b->tm_min))	   * 60)	  + (a->tm_sec - b->tm_sec));} /*   * Adjust time T by adding SECONDS.  SECONDS must be at most 24 hours' worth.   * Adjust only T's year, mon, mday, hour, min and sec members;   * plus adjust wday if it is defined. */voidadjzone (t, seconds)     register struct tm *t;     long seconds;{  /*     * This code can be off by a second if SECONDS is not a multiple of 60,     * if T is local time, and if a leap second happens during this minute.     * But this bug has never occurred, and most likely will not ever occur.     * Liberia, the last country for which SECONDS % 60 was nonzero,     * switched to UTC in May 1972; the first leap second was in June 1972.   */  int leap_second = t->tm_sec == 60;  long sec = seconds + (t->tm_sec - leap_second);  if (sec < 0)    {      if ((t->tm_min -= (59 - sec) / 60) < 0)	{	  if ((t->tm_hour -= (59 - t->tm_min) / 60) < 0)	    {	      t->tm_hour += 24;	      if (TM_DEFINED (t->tm_wday) && --t->tm_wday < 0)		t->tm_wday = 6;	      if (--t->tm_mday <= 0)		{		  if (--t->tm_mon < 0)		    {		      --t->tm_year;		      t->tm_mon = 11;		    }		  t->tm_mday = month_days (t);		}	    }	  t->tm_min += 24 * 60;	}      sec += 24L * 60 * 60;    }  else if (60 <= (t->tm_min += sec / 60))    if (24 <= (t->tm_hour += t->tm_min / 60))      {	t->tm_hour -= 24;	if (TM_DEFINED (t->tm_wday) && ++t->tm_wday == 7)	  t->tm_wday = 0;	if (month_days (t) < ++t->tm_mday)	  {	    if (11 < ++t->tm_mon)	      {		++t->tm_year;		t->tm_mon = 0;	      }	    t->tm_mday = 1;	  }      }  t->tm_min %= 60;  t->tm_sec = (int) (sec % 60) + leap_second;} /*   * Convert TM to time_t, using localtime if LOCALZONE and gmtime otherwise.   * Use only TM's year, mon, mday, hour, min, and sec members.   * Ignore TM's old tm_yday and tm_wday, but fill in their correct values.   * Yield -1 on failure (e.g. a member out of range).   * Posix 1003.1-1990 doesn't allow leap seconds, but some implementations   * have them anyway, so allow them if localtime/gmtime does. */time_ttm2time (tm, localzone)     struct tm *tm;     int localzone;{  /* Cache the most recent t,tm pairs; 1 for gmtime, 1 for localtime.  */  static time_t t_cache[2];  static struct tm tm_cache[2];   time_t d, gt;  struct tm const *gtm;  /*     * The maximum number of iterations should be enough to handle any     * combinations of leap seconds, time zone rule changes, and solar time.     * 4 is probably enough; we use a bigger number just to be safe.   */  int remaining_tries = 8;   /* Avoid subscript errors.  */  if (12 <= (unsigned) tm->tm_mon)    return -1;   tm->tm_yday = month_yday[tm->tm_mon] + tm->tm_mday    - (tm->tm_mon < 2 || !isleap (tm->tm_year + TM_YEAR_ORIGIN));   /* Make a first guess.  */  gt = t_cache[localzone];  gtm = gt ? &tm_cache[localzone] : time2tm (gt, localzone);   /* Repeatedly use the error from the guess to improve the guess.  */  while ((d = difftm (tm, gtm)) != 0)    {      if (--remaining_tries == 0)	return -1;      gt += d;      gtm = time2tm (gt, localzone);    }   /*     * Check that the guess actually matches;     * overflow can cause difftm to yield 0 even on differing times,     * or tm may have members out of range (e.g. bad leap seconds).   */#define TM_DIFFER(a,b) \		( \			((a)->tm_year ^ (b)->tm_year) | \			((a)->tm_mon ^ (b)->tm_mon) | \			((a)->tm_mday ^ (b)->tm_mday) | \			((a)->tm_hour ^ (b)->tm_hour) | \			((a)->tm_min ^ (b)->tm_min) | \			((a)->tm_sec ^ (b)->tm_sec) \		)  if (TM_DIFFER (tm, gtm))    {      /*         * If gt is a leap second, try gt+1; if it is one greater than         * a leap second, try gt-1; otherwise, it doesn't matter.         * Leap seconds always fall at month end.       */      int yd = tm->tm_year - gtm->tm_year;      gt += yd + (yd ? 0 : tm->tm_mon - gtm->tm_mon);      gtm = time2tm (gt, localzone);      if (TM_DIFFER (tm, gtm))	return -1;    }  t_cache[localzone] = gt;  tm_cache[localzone] = *gtm;   tm->tm_wday = gtm->tm_wday;  return gt;} /*   * Check *PT and convert it to time_t.   * If it is incompletely specified, use DEFAULT_TIME to fill it out.   * Use localtime if PT->zone is the special value TM_LOCAL_ZONE.   * Yield -1 on failure.   * ISO 8601 day-of-year and week numbers are not yet supported. */static time_tmaketime (pt, default_time)     struct partime const *pt;     time_t default_time;{  int localzone, wday;  struct tm tm;  struct tm *tm0 = 0;  time_t r;   tm0 = 0;			/* Keep gcc -Wall happy.  */  localzone = pt->zone == TM_LOCAL_ZONE;   tm = pt->tm;   if (TM_DEFINED (pt->ymodulus) || !TM_DEFINED (tm.tm_year))    {      /* Get tm corresponding to default time.  */      tm0 = time2tm (default_time, localzone);      if (!localzone)	adjzone (tm0, pt->zone);    }   if (TM_DEFINED (pt->ymodulus))    tm.tm_year +=      (tm0->tm_year + TM_YEAR_ORIGIN) / pt->ymodulus * pt->ymodulus;  else if (!TM_DEFINED (tm.tm_year))    {      /* Set default year, month, day from current time.  */      tm.tm_year = tm0->tm_year + TM_YEAR_ORIGIN;      if (!TM_DEFINED (tm.tm_mon))	{	  tm.tm_mon = tm0->tm_mon;	  if (!TM_DEFINED (tm.tm_mday))	    tm.tm_mday = tm0->tm_mday;	}    }   /* Convert from partime year (Gregorian) to Posix year.  */  tm.tm_year -= TM_YEAR_ORIGIN;   /* Set remaining default fields to be their minimum values.  */  if (!TM_DEFINED (tm.tm_mon))    tm.tm_mon = 0;  if (!TM_DEFINED (tm.tm_mday))    tm.tm_mday = 1;  if (!TM_DEFINED (tm.tm_hour))    tm.tm_hour = 0;  if (!TM_DEFINED (tm.tm_min))    tm.tm_min = 0;  if (!TM_DEFINED (tm.tm_sec))    tm.tm_sec = 0;   if (!localzone)    adjzone (&tm, -pt->zone);  wday = tm.tm_wday;   /* Convert and fill in the rest of the tm.  */  r = tm2time (&tm, localzone);   /* Check weekday.  */  if (r != -1 && TM_DEFINED (wday) && wday != tm.tm_wday)    return -1;   return r;} /* Parse a free-format date in SOURCE, yielding a Unix format time.  */time_tstr2time (source, default_time, default_zone)     char const *source;     time_t default_time;     long default_zone;{  struct partime pt;   if (*partime (source, &pt))    return -1;  if (pt.zone == TM_UNDEFINED_ZONE)    pt.zone = default_zone;  return maketime (&pt, default_time);} #if TEST#include <stdio.h>intmain (argc, argv)     int argc;     char **argv;{  time_t default_time = time ((time_t *) 0);  long default_zone = argv[1] ? atol (argv[1]) : 0;  char buf[1000];  while (fgets (buf, sizeof (buf), stdin))    {      time_t t = str2time (buf, default_time, default_zone);      printf ("%s", asctime (gmtime (&t)));    }  return 0;}#endif