-/* mktime.c */
-
-/* Copyright (C) 1993 Free Software Foundation, Inc.
-
-This file is part of the GNU Accounting Utilities
-
-The GNU Accounting Utilities are free software; you can redistribute
-them and/or modify them 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.
-
-The GNU Accounting Utilities are distributed in the hope that they 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 the GNU Accounting Utilities; see the file COPYING. If
-not, write to the Free Software Foundation, 675 Mass Ave, Cambridge,
-MA 02139, USA. */
-
-/* provided for those systems that don't have their own.
- *
- * after testing this, the maximum number of iterations that I had on
- * any number that I tried was 3! Not bad.
- *
- * -----------------------THE-LOWDOWN-ON-MKTIME-----------------------------
- *
- * time_t mktime (timeptr)
- * struct tm *timeptr;
- *
- * --- the struct tm from the time.h header file
- *
- * struct tm {
- * int tm_sec; seconds (0 - 59)
- * int tm_min; minutes (0 - 59)
- * int tm_hour; hours (0 - 23)
- * int tm_mday; day of month (1 - 31)
- * int tm_mon; month of year (0 - 11)
- * int tm_year; year - 1900
- * int tm_wday; day of week (Sunday = 0)
- * int tm_yday; day of year (0 - 365)
- * int tm_isdst; daylight savings time flag
- * long tm_gmtoff; offset from GMT in seconds
- * char *tm_zone; abbreviation of timezone name
- * };
- *
- * tm_isdst is nonzero if DST is in effect.
- *
- * tm_gmtoff is the offset (in seconds) of the time represented from GMT,
- * with positive values indicating East of Greenwich.
- *
- * --- description
- *
- * mktime converts a struct tm (broken-down local time) into a time_t
- * -- it it is the opposite of localtime(3). It is possible to put
- * the following values out of range and have mktime compensate:
- * tm_sec, tm_min, tm_hour, tm_mday, tm_year. The other values in the
- * structure are ignored.
- *
- * The manual claims that a negative value for tm_isdst makes mktime
- * determine whether daylight savings time was in effect for the
- * specified time, but through observation this does not seem to be
- * the case. mktime always returns the correct DST flag.
- *
- * The manual page ALSO claims that if a calendar time cannot be
- * represented, it will return -1. Not so. I've tried the entire
- * range of time_t (longs) on several systems and never had -1
- * returned, save for Dec 31, 1969, 23:59:59... */
-
+/* Copyright (C) 1993, 1994 Free Software Foundation, Inc.
+ Contributed by Noel Cragg (noel@cs.oberlin.edu).
+
+This file is part of the GNU C Library.
+
+The GNU C Library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Library General Public License as
+published by the Free Software Foundation; either version 2 of the
+License, or (at your option) any later version.
+
+The GNU C Library 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB. If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA. */
+
+/* Define this to have a standalone program to test this implementation of
+ mktime. */
+/* #define DEBUG */
+
+#ifdef HAVE_CONFIG_H
+#if defined (CONFIG_BROKETS)
+/* We use <config.h> instead of "config.h" so that a compilation
+ using -I. -I$srcdir will use ./config.h rather than $srcdir/config.h
+ (which it would do because it found this file in $srcdir). */
+#include <config.h>
+#else
#include "config.h"
+#endif
+#endif
-#ifndef HAVE_MKTIME
-
-#include <stdio.h>
+#include <sys/types.h> /* Some systems define `time_t' here. */
#include <time.h>
-#include <sys/types.h>
-/* #define DEBUG */ /* define this to have a standalone shell to test
- * this implementation of mktime
- */
-static char rcsid[] = "$Id$";
+#ifndef __isleap
+/* Nonzero if YEAR is a leap year (every 4 years,
+ except every 100th isn't, and every 400th is). */
+#define __isleap(year) \
+ ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
+#endif
-static int times_through_search; /* this library routine should never
+#ifndef __P
+#if defined (__GNUC__) || (defined (__STDC__) && __STDC__)
+#define __P(args) args
+#else
+#define __P(args) ()
+#endif /* GCC. */
+#endif /* Not __P. */
+
+/* How many days are in each month. */
+const unsigned short int __mon_lengths[2][12] =
+ {
+ /* Normal years. */
+ { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
+ /* Leap years. */
+ { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
+ };
+
+
+static int times_through_search; /* This library routine should never
hang -- make sure we always return
when we're searching for a value */
+/* After testing this, the maximum number of iterations that I had on
+ any number that I tried was 3! Not bad.
+
+ mktime converts a `struct tm' (broken-down local time) into a `time_t';
+ it is the opposite of localtime. It is possible to put the following
+ values out of range and have mktime compensate: tm_sec, tm_min, tm_hour,
+ tm_mday, tm_year. The other values in the structure are ignored. */
+
#ifdef DEBUG
+#include <stdio.h>
+#include <ctype.h>
+
int debugging_enabled = 0;
-/* print the values in a tm structure */
-void
-printtm (struct tm *it)
+/* Print the values in a `struct tm'. */
+static void
+printtm (it)
+ struct tm *it;
{
printf ("%d/%d/%d %d:%d:%d (%s) yday:%d f:%d o:%ld",
it->tm_mon,
#endif
-/* return 1 if the YR is a leap year
- *
- * actually, it's a Steve Tibbets album
- */
-static
-int
-leap_year (int yr)
-{
- int year = yr + 1900;
-
- if ((year % 400) == 0)
- return 1;
- else if (((year % 4) == 0) && ((year % 100) != 0))
- return 1;
- else
- return 0;
-}
-
-
-/* not pretty, but it's fast */
-
-static
-time_t
-olddist_tm (struct tm *t1, struct tm *t2)
-{
- time_t distance = 0; /* linear distance in seconds */
- int diff_flag = 0;
-
-#define doit(x,secs); \
- if (t1->x != t2->x) diff_flag = 1; \
- distance -= (t2->x - t1->x) * secs;
-
- doit (tm_year, 31536000);
- doit (tm_yday, 86400);
- doit (tm_hour, 3600);
- doit (tm_min, 60);
- doit (tm_sec, 1);
-
-#undef doit
-
- /* we need this DIFF_FLAG business because it is forseeable that
- * the distance may be zero when, in actuality, the two structures
- * are different. This is usually the case when the dates are
- * 366 days apart and one of the years is a leap year */
-
- if ((distance == 0) && diff_flag)
- distance += 86400;
-
- return distance;
-}
-
-
-static
-time_t
-dist_tm (struct tm *t1, struct tm *t2)
+static time_t
+dist_tm (t1, t2)
+ struct tm *t1;
+ struct tm *t2;
{
time_t distance = 0;
- unsigned long v1, v2;
+ unsigned long int v1, v2;
int diff_flag = 0;
v1 = v2 = 0;
-#define doit(x,secs); \
- v1 += t1->x * secs; \
- v2 += t2->x * secs; \
- if (!diff_flag) \
- { \
- if (t1->x < t2->x) \
- { \
- diff_flag = -1; \
- } \
- else if (t1->x > t2->x) \
- { \
- diff_flag = 1; \
- } \
- }
+#define doit(x, secs) \
+ v1 += t1->x * secs; \
+ v2 += t2->x * secs; \
+ if (!diff_flag) \
+ { \
+ if (t1->x < t2->x) \
+ diff_flag = -1; \
+ else if (t1->x > t2->x) \
+ diff_flag = 1; \
+ }
- doit (tm_year, 31536000); /* okay, not all years have 365 days */
- doit (tm_mon, 2592000); /* okay, not all months have 30 days */
+ doit (tm_year, 31536000); /* Okay, not all years have 365 days. */
+ doit (tm_mon, 2592000); /* Okay, not all months have 30 days. */
doit (tm_mday, 86400);
doit (tm_hour, 3600);
doit (tm_min, 60);
#undef doit
- /* we should also make sure that the sign of DISTANCE is correct --
- * if DIFF_FLAG is positive, the distance should be positive and
- * vice versa. */
+ /* We should also make sure that the sign of DISTANCE is correct -- if
+ DIFF_FLAG is positive, the distance should be positive and vice versa. */
distance = (v1 > v2) ? (v1 - v2) : (v2 - v1);
if (diff_flag < 0)
distance = -distance;
- if (times_through_search > 20) /* arbitrary # of calls, but makes
- sure we never hang if there's a
- problem with this algorithm */
+ if (times_through_search > 20) /* Arbitrary # of calls, but makes sure we
+ never hang if there's a problem with
+ this algorithm. */
{
distance = diff_flag;
}
- /* we need this DIFF_FLAG business because it is forseeable that
- * the distance may be zero when, in actuality, the two structures
- * are different. This is usually the case when the dates are
- * 366 days apart and one of the years is a leap year */
+ /* We need this DIFF_FLAG business because it is forseeable that the
+ distance may be zero when, in actuality, the two structures are
+ different. This is usually the case when the dates are 366 days apart
+ and one of the years is a leap year. */
- if ((distance == 0) && diff_flag) distance = 86400 * diff_flag;
+ if (distance == 0 && diff_flag)
+ distance = 86400 * diff_flag;
return distance;
}
-/* modified b-search -- make intelligent guesses as to where the time
- * might lie along the timeline, assuming that our target time lies a
- * linear distance (w/o considering time jumps of a particular region)
- *
- * assume that time does not fluctuate at all along the timeline --
- * e.g., assume that a day will always take 86400 seconds, etc. -- and
- * come up with a hypothetical value for the time_t representation of
- * the struct tm TARGET, in relation to the guess variable -- it should
- * be pretty close! */
-
-static
-time_t
-search (struct tm *target)
+/* Modified b-search -- make intelligent guesses as to where the time might
+ lie along the timeline, assuming that our target time lies a linear
+ distance (w/o considering time jumps of a particular region).
+
+ Assume that time does not fluctuate at all along the timeline -- e.g.,
+ assume that a day will always take 86400 seconds, etc. -- and come up
+ with a hypothetical value for the time_t representation of the struct tm
+ TARGET, in relation to the guess variable -- it should be pretty close! */
+
+static time_t
+search (target, producer)
+ struct tm *target;
+ struct tm *(*producer) __P ((const time_t *));
{
struct tm *guess_tm;
time_t guess = 0;
- time_t distance;
+ time_t distance = 0;
times_through_search = 0;
- for (;;)
+ do
{
- guess_tm = localtime (&guess);
+ guess += distance;
+
+ times_through_search++;
+
+ guess_tm = (*producer) (&guess);
#ifdef DEBUG
if (debugging_enabled)
{
- printf ("guess %d == ", guess);
+ printf ("guess %d == ", (int) guess);
printtm (guess_tm);
- printf ("\n");
+ puts ("");
}
#endif
- /* are we on the money? */
+ /* Are we on the money? */
distance = dist_tm (target, guess_tm);
- if (distance == 0)
- {
- /* yes, we got it! Get out of here! */
- return guess;
- }
+ } while (distance != 0);
- guess += distance;
-
- times_through_search++;
- }
+ return guess;
}
-/* since this function will call localtime many times (and the user might
- * be passing their struct tm * right from localtime, let's make a copy
- * for ourselves and run the search on the copy.
- *
- * also, we have to normalize the timeptr because it's possible to call mktime
- * with values that are out of range for a specific item (like 30th Feb)...
- */
-#ifdef DEBUG
-time_t
-my_mktime (struct tm *timeptr)
-#else
+/* Since this function will call localtime many times (and the user might
+ be passing their `struct tm *' right from localtime, let's make a copy
+ for ourselves and run the search on the copy.
+
+ Also, we have to normalize *TIMEPTR because it's possible to call mktime
+ with values that are out of range for a specific item (like Feb 30th). */
time_t
-mktime (struct tm *timeptr)
-#endif
+_mktime_internal (timeptr, producer)
+ struct tm *timeptr;
+ struct tm *(*producer) __P ((const time_t *));
{
- struct tm private_mktime_struct_tm; /* yes, users can get a ptr to this */
+ struct tm private_mktime_struct_tm; /* Yes, users can get a ptr to this. */
struct tm *me;
time_t result;
- int month_data[2][12] = {
- { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
- { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
- };
-
me = &private_mktime_struct_tm;
- memcpy ((void *) me, (void *) timeptr, sizeof (struct tm));
+ *me = *timeptr;
#define normalize(foo,x,y,bar); \
while (me->foo < x) \
me->foo = (x + (me->foo - y)); \
}
- normalize (tm_sec,0,59,tm_min);
- normalize (tm_min,0,59,tm_hour);
- normalize (tm_hour,0,23,tm_mday);
+ normalize (tm_sec, 0, 59, tm_min);
+ normalize (tm_min, 0, 59, tm_hour);
+ normalize (tm_hour, 0, 23, tm_mday);
- /* do month first, so day range can be found */
- normalize (tm_mon,0,11,tm_year);
- normalize (tm_mday,1,month_data[leap_year (me->tm_year)][me->tm_mon],tm_mon);
-
- /* do month again, because day may have pushed it out of range */
- normalize (tm_mon,0,11,tm_year);
-
- /* do day again, because month may have changed the range */
- normalize (tm_mday,1,month_data[leap_year (me->tm_year)][me->tm_mon],tm_mon);
+ /* Do the month first, so day range can be found. */
+ normalize (tm_mon, 0, 11, tm_year);
+ normalize (tm_mday, 1,
+ __mon_lengths[__isleap (me->tm_year)][me->tm_mon],
+ tm_mon);
+
+ /* Do the month again, because the day may have pushed it out of range. */
+ normalize (tm_mon, 0, 11, tm_year);
+
+ /* Do the day again, because the month may have changed the range. */
+ normalize (tm_mday, 1,
+ __mon_lengths[__isleap (me->tm_year)][me->tm_mon],
+ tm_mon);
#ifdef DEBUG
if (debugging_enabled)
{
printf ("After normalizing: ");
printtm (me);
- printf ("\n\n");
+ puts ("\n");
}
#endif
- result = search (me);
+ result = search (me, producer);
+
+ *timeptr = *me;
return result;
}
-
+time_t
+mktime (timeptr)
+ struct tm *timeptr;
+{
+ return _mktime_internal (timeptr, localtime);
+}
+\f
#ifdef DEBUG
void
-main (int argc, char *argv[])
+main (argc, argv)
+ int argc;
+ char *argv[];
{
int time;
int result_time;
{
struct tm *tm = localtime (&q);
if ((q % 10000) == 0) { printf ("%ld\n", q); fflush (stdout); }
- if (q != my_mktime (tm))
+ if (q != mktime (tm))
{ printf ("failed for %ld\n", q); fflush (stdout); }
}
exit (0);
}
- debugging_enabled = 1; /* we want to see the info */
+ debugging_enabled = 1; /* We want to see the info */
++argv;
time = atoi (*argv);
- printf ("Time: %d %s\n", time, ctime (&time));
+ printf ("Time: %d %s\n", time, ctime ((time_t *) &time));
- tmptr = localtime (&time);
+ tmptr = localtime ((time_t *) &time);
printf ("localtime returns: ");
printtm (tmptr);
printf ("\n");
-#ifdef HAVE_MKTIME
- printf ("system mktime: %d\n\n", mktime (tmptr));
-#endif
- printf (" my mktime(): %d\n\n", my_mktime (tmptr));
+ printf ("mktime: %d\n\n", (int) mktime (tmptr));
tmptr->tm_sec -= 20;
tmptr->tm_min -= 20;
tmptr->tm_mday -= 20;
tmptr->tm_mon -= 20;
tmptr->tm_year -= 20;
- tmptr->tm_gmtoff -= 20000; /* this has no effect! */
- tmptr->tm_zone = NULL; /* nor does this! */
+ tmptr->tm_gmtoff -= 20000; /* This has no effect! */
+ tmptr->tm_zone = NULL; /* Nor does this! */
tmptr->tm_isdst = -1;
printf ("changed ranges: ");
printtm (tmptr);
printf ("\n\n");
- result_time = my_mktime (tmptr);
- printf ("\n mine: %d\n", result_time);
-#ifdef HAVE_MKTIME
- printf ("system: %d\n", mktime (tmptr));
-#endif
+ result_time = mktime (tmptr);
+ printf ("\nmktime: %d\n", result_time);
}
#endif /* DEBUG */
-
-#endif /* HAVE_MKTIME */
-
projects / kopensolaris-gnu / glibc.git / blobdiff