X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fmktime.c;h=c8ecd07f12b6592b92b6425e7bf353d316b41550;hb=b2dc4ba801547267ee35c2a5117c2b4ca8a9acbf;hp=07fe494f47540efa698f999f19531f9db7ca7226;hpb=6a75c0b2de353ea0aaa7741d8624aec4fdefcdfd;p=gnulib.git diff --git a/lib/mktime.c b/lib/mktime.c index 07fe494f4..c8ecd07f1 100644 --- a/lib/mktime.c +++ b/lib/mktime.c @@ -1,343 +1,528 @@ -/* 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. */ +/* Convert a `struct tm' to a time_t value. + Copyright (C) 1993, 94, 95, 96, 97, 98, 99 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Paul Eggert (eggert@twinsun.com). + + 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., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ /* Define this to have a standalone program to test this implementation of mktime. */ -/* #define DEBUG */ +/* #define DEBUG 1 */ #ifdef HAVE_CONFIG_H -#if defined (CONFIG_BROKETS) -/* We use 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 -#else -#include "config.h" +# include #endif + +#ifdef _LIBC +# define HAVE_LIMITS_H 1 +# define STDC_HEADERS 1 +#endif + +/* Assume that leap seconds are possible, unless told otherwise. + If the host has a `zic' command with a `-L leapsecondfilename' option, + then it supports leap seconds; otherwise it probably doesn't. */ +#ifndef LEAP_SECONDS_POSSIBLE +# define LEAP_SECONDS_POSSIBLE 1 #endif #include /* Some systems define `time_t' here. */ #include - -#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)) +#if HAVE_LIMITS_H +# include #endif +#if DEBUG +# include +# if STDC_HEADERS +# include +# endif +/* Make it work even if the system's libc has its own mktime routine. */ +# define mktime my_mktime +#endif /* DEBUG */ + #ifndef __P -#if defined (__GNUC__) || (defined (__STDC__) && __STDC__) -#define __P(args) args -#else -#define __P(args) () -#endif /* GCC. */ +# 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 } - }; +#ifndef CHAR_BIT +# define CHAR_BIT 8 +#endif +/* The extra casts work around common compiler bugs. */ +#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1)) +/* The outer cast is needed to work around a bug in Cray C 5.0.3.0. + It is necessary at least when t == time_t. */ +#define TYPE_MINIMUM(t) ((t) (TYPE_SIGNED (t) \ + ? ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1) : (t) 0)) +#define TYPE_MAXIMUM(t) ((t) (~ (t) 0 - TYPE_MINIMUM (t))) -static int times_through_search; /* This library routine should never - hang -- make sure we always return - when we're searching for a value */ +#ifndef INT_MIN +# define INT_MIN TYPE_MINIMUM (int) +#endif +#ifndef INT_MAX +# define INT_MAX TYPE_MAXIMUM (int) +#endif -/* After testing this, the maximum number of iterations that I had on - any number that I tried was 3! Not bad. +#ifndef TIME_T_MIN +# define TIME_T_MIN TYPE_MINIMUM (time_t) +#endif +#ifndef TIME_T_MAX +# define TIME_T_MAX TYPE_MAXIMUM (time_t) +#endif - 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. */ +#define TM_YEAR_BASE 1900 +#define EPOCH_YEAR 1970 -#ifdef DEBUG +#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 -#include -#include +/* How many days come before each month (0-12). */ +const unsigned short int __mon_yday[2][13] = + { + /* Normal years. */ + { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 }, + /* Leap years. */ + { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 } + }; -int debugging_enabled = 0; -/* Print the values in a `struct tm'. */ -static void -printtm (it) - struct tm *it; +#ifdef _LIBC +# define my_mktime_localtime_r __localtime_r +#else +/* If we're a mktime substitute in a GNU program, then prefer + localtime to localtime_r, since many localtime_r implementations + are buggy. */ +static struct tm * +my_mktime_localtime_r (const time_t *t, struct tm *tp) { - printf ("%d/%d/%d %d:%d:%d (%s) yday:%d f:%d o:%ld", - it->tm_mon, - it->tm_mday, - it->tm_year, - it->tm_hour, - it->tm_min, - it->tm_sec, - it->tm_zone, - it->tm_yday, - it->tm_isdst, - it->tm_gmtoff); + struct tm *l = localtime (t); + if (! l) + return 0; + *tp = *l; + return tp; } -#endif +#endif /* ! _LIBC */ +/* Yield the difference between (YEAR-YDAY HOUR:MIN:SEC) and (*TP), + measured in seconds, ignoring leap seconds. + YEAR uses the same numbering as TM->tm_year. + All values are in range, except possibly YEAR. + If TP is null, return a nonzero value. + If overflow occurs, yield the low order bits of the correct answer. */ static time_t -dist_tm (t1, t2) - struct tm *t1; - struct tm *t2; +ydhms_tm_diff (int year, int yday, int hour, int min, int sec, + const struct tm *tp) { - time_t distance = 0; - 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; \ - } - - 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); - doit (tm_sec, 1); - -#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. */ - - 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 (!tp) + return 1; + else { - distance = diff_flag; + /* Compute intervening leap days correctly even if year is negative. + Take care to avoid int overflow. time_t overflow is OK, since + only the low order bits of the correct time_t answer are needed. + Don't convert to time_t until after all divisions are done, since + time_t might be unsigned. */ + int a4 = (year >> 2) + (TM_YEAR_BASE >> 2) - ! (year & 3); + int b4 = (tp->tm_year >> 2) + (TM_YEAR_BASE >> 2) - ! (tp->tm_year & 3); + int a100 = a4 / 25 - (a4 % 25 < 0); + int b100 = b4 / 25 - (b4 % 25 < 0); + int a400 = a100 >> 2; + int b400 = b100 >> 2; + int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400); + time_t years = year - (time_t) tp->tm_year; + time_t days = (365 * years + intervening_leap_days + + (yday - tp->tm_yday)); + return (60 * (60 * (24 * days + (hour - tp->tm_hour)) + + (min - tp->tm_min)) + + (sec - tp->tm_sec)); } +} + +/* Use CONVERT to convert *T to a broken down time in *TP. + If *T is out of range for conversion, adjust it so that + it is the nearest in-range value and then convert that. */ +static struct tm * +ranged_convert (struct tm *(*convert) (const time_t *, struct tm *), + time_t *t, struct tm *tp) +{ + struct tm *r; - /* 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 (! (r = (*convert) (t, tp)) && *t) + { + time_t bad = *t; + time_t ok = 0; + struct tm tm; + + /* BAD is a known unconvertible time_t, and OK is a known good one. + Use binary search to narrow the range between BAD and OK until + they differ by 1. */ + while (bad != ok + (bad < 0 ? -1 : 1)) + { + time_t mid = *t = (bad < 0 + ? bad + ((ok - bad) >> 1) + : ok + ((bad - ok) >> 1)); + if ((r = (*convert) (t, tp))) + { + tm = *r; + ok = mid; + } + else + bad = mid; + } - if (distance == 0 && diff_flag) - distance = 86400 * diff_flag; + if (!r && ok) + { + /* The last conversion attempt failed; + revert to the most recent successful attempt. */ + *t = ok; + *tp = tm; + r = tp; + } + } - return distance; + return r; } - -/* 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 *)); +/* Convert *TP to a time_t value, inverting + the monotonic and mostly-unit-linear conversion function CONVERT. + Use *OFFSET to keep track of a guess at the offset of the result, + compared to what the result would be for UTC without leap seconds. + If *OFFSET's guess is correct, only one CONVERT call is needed. */ +time_t +__mktime_internal (struct tm *tp, + struct tm *(*convert) (const time_t *, struct tm *), + time_t *offset) { - struct tm *guess_tm; - time_t guess = 0; - time_t distance = 0; - - times_through_search = 0; + time_t t, dt, t0, t1, t2; + struct tm tm; + + /* The maximum number of probes (calls to CONVERT) should be enough + to handle any combinations of time zone rule changes, solar time, + leap seconds, and oscillations around a spring-forward gap. + POSIX.1 prohibits leap seconds, but some hosts have them anyway. */ + int remaining_probes = 6; + + /* Time requested. Copy it in case CONVERT modifies *TP; this can + occur if TP is localtime's returned value and CONVERT is localtime. */ + int sec = tp->tm_sec; + int min = tp->tm_min; + int hour = tp->tm_hour; + int mday = tp->tm_mday; + int mon = tp->tm_mon; + int year_requested = tp->tm_year; + int isdst = tp->tm_isdst; + + /* Ensure that mon is in range, and set year accordingly. */ + int mon_remainder = mon % 12; + int negative_mon_remainder = mon_remainder < 0; + int mon_years = mon / 12 - negative_mon_remainder; + int year = year_requested + mon_years; + + /* The other values need not be in range: + the remaining code handles minor overflows correctly, + assuming int and time_t arithmetic wraps around. + Major overflows are caught at the end. */ + + /* Calculate day of year from year, month, and day of month. + The result need not be in range. */ + int yday = ((__mon_yday[__isleap (year + TM_YEAR_BASE)] + [mon_remainder + 12 * negative_mon_remainder]) + + mday - 1); + + int sec_requested = sec; +#if LEAP_SECONDS_POSSIBLE + /* Handle out-of-range seconds specially, + since ydhms_tm_diff assumes every minute has 60 seconds. */ + if (sec < 0) + sec = 0; + if (59 < sec) + sec = 59; +#endif - do + /* Invert CONVERT by probing. First assume the same offset as last time. + Then repeatedly use the error to improve the guess. */ + + tm.tm_year = EPOCH_YEAR - TM_YEAR_BASE; + tm.tm_yday = tm.tm_hour = tm.tm_min = tm.tm_sec = 0; + t0 = ydhms_tm_diff (year, yday, hour, min, sec, &tm); + + for (t = t1 = t2 = t0 + *offset; + (dt = ydhms_tm_diff (year, yday, hour, min, sec, + ranged_convert (convert, &t, &tm))); + t1 = t2, t2 = t, t += dt) + if (t == t1 && t != t2 + && (isdst < 0 || tm.tm_isdst < 0 + || (isdst != 0) != (tm.tm_isdst != 0))) + /* We can't possibly find a match, as we are oscillating + between two values. The requested time probably falls + within a spring-forward gap of size DT. Follow the common + practice in this case, which is to return a time that is DT + away from the requested time, preferring a time whose + tm_isdst differs from the requested value. In practice, + this is more useful than returning -1. */ + break; + else if (--remaining_probes == 0) + return -1; + + /* If we have a match, check whether tm.tm_isdst has the requested + value, if any. */ + if (dt == 0 && isdst != tm.tm_isdst && 0 <= isdst && 0 <= tm.tm_isdst) { - guess += distance; - - times_through_search++; - - guess_tm = (*producer) (&guess); - -#ifdef DEBUG - if (debugging_enabled) + /* tm.tm_isdst has the wrong value. Look for a neighboring + time with the right value, and use its UTC offset. + Heuristic: probe the previous three calendar quarters (approximately), + looking for the desired isdst. This isn't perfect, + but it's good enough in practice. */ + int quarter = 7889238; /* seconds per average 1/4 Gregorian year */ + int i; + + /* If we're too close to the time_t limit, look in future quarters. */ + if (t < TIME_T_MIN + 3 * quarter) + quarter = -quarter; + + for (i = 1; i <= 3; i++) { - printf ("guess %d == ", (int) guess); - printtm (guess_tm); - puts (""); + time_t ot = t - i * quarter; + struct tm otm; + ranged_convert (convert, &ot, &otm); + if (otm.tm_isdst == isdst) + { + /* We found the desired tm_isdst. + Extrapolate back to the desired time. */ + t = ot + ydhms_tm_diff (year, yday, hour, min, sec, &otm); + ranged_convert (convert, &t, &tm); + break; + } } + } + + *offset = t - t0; + +#if LEAP_SECONDS_POSSIBLE + if (sec_requested != tm.tm_sec) + { + /* Adjust time to reflect the tm_sec requested, not the normalized value. + Also, repair any damage from a false match due to a leap second. */ + t += sec_requested - sec + (sec == 0 && tm.tm_sec == 60); + if (! (*convert) (&t, &tm)) + return -1; + } #endif - - /* Are we on the money? */ - distance = dist_tm (target, guess_tm); - - } while (distance != 0); - return guess; + if (TIME_T_MAX / INT_MAX / 366 / 24 / 60 / 60 < 3) + { + /* time_t isn't large enough to rule out overflows in ydhms_tm_diff, + so check for major overflows. A gross check suffices, + since if t has overflowed, it is off by a multiple of + TIME_T_MAX - TIME_T_MIN + 1. So ignore any component of + the difference that is bounded by a small value. */ + + double dyear = (double) year_requested + mon_years - tm.tm_year; + double dday = 366 * dyear + mday; + double dsec = 60 * (60 * (24 * dday + hour) + min) + sec_requested; + + /* On Irix4.0.5 cc, dividing TIME_T_MIN by 3 does not produce + correct results, ie., it erroneously gives a positive value + of 715827882. Setting a variable first then doing math on it + seems to work. (ghazi@caip.rutgers.edu) */ + + const time_t time_t_max = TIME_T_MAX; + const time_t time_t_min = TIME_T_MIN; + + if (time_t_max / 3 - time_t_min / 3 < (dsec < 0 ? - dsec : dsec)) + return -1; + } + + *tp = tm; + return t; } -/* 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). */ +static time_t localtime_offset; + +/* Convert *TP to a time_t value. */ time_t -_mktime_internal (timeptr, producer) - struct tm *timeptr; - struct tm *(*producer) __P ((const time_t *)); +mktime (tp) + struct tm *tp; { - struct tm private_mktime_struct_tm; /* Yes, users can get a ptr to this. */ - struct tm *me; - time_t result; - - me = &private_mktime_struct_tm; - - *me = *timeptr; - -#define normalize(foo,x,y,bar); \ - while (me->foo < x) \ - { \ - me->bar--; \ - me->foo = (y - (x - me->foo)); \ - } \ - while (me->foo > y) \ - { \ - me->bar++; \ - 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); - - /* 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); - puts ("\n"); - } +#ifdef _LIBC + /* POSIX.1 8.1.1 requires that whenever mktime() is called, the + time zone names contained in the external variable `tzname' shall + be set as if the tzset() function had been called. */ + __tzset (); #endif - result = search (me, producer); + return __mktime_internal (tp, my_mktime_localtime_r, &localtime_offset); +} - *timeptr = *me; +#ifdef weak_alias +weak_alias (mktime, timelocal) +#endif + +#if DEBUG - return result; +static int +not_equal_tm (a, b) + struct tm *a; + struct tm *b; +{ + return ((a->tm_sec ^ b->tm_sec) + | (a->tm_min ^ b->tm_min) + | (a->tm_hour ^ b->tm_hour) + | (a->tm_mday ^ b->tm_mday) + | (a->tm_mon ^ b->tm_mon) + | (a->tm_year ^ b->tm_year) + | (a->tm_mday ^ b->tm_mday) + | (a->tm_yday ^ b->tm_yday) + | (a->tm_isdst ^ b->tm_isdst)); } -time_t -mktime (timeptr) - struct tm *timeptr; +static void +print_tm (tp) + struct tm *tp; { - return _mktime_internal (timeptr, localtime); + if (tp) + printf ("%04d-%02d-%02d %02d:%02d:%02d yday %03d wday %d isdst %d", + tp->tm_year + TM_YEAR_BASE, tp->tm_mon + 1, tp->tm_mday, + tp->tm_hour, tp->tm_min, tp->tm_sec, + tp->tm_yday, tp->tm_wday, tp->tm_isdst); + else + printf ("0"); } - -#ifdef DEBUG -void + +static int +check_result (tk, tmk, tl, lt) + time_t tk; + struct tm tmk; + time_t tl; + struct tm *lt; +{ + if (tk != tl || !lt || not_equal_tm (&tmk, lt)) + { + printf ("mktime ("); + print_tm (&tmk); + printf (")\nyields ("); + print_tm (lt); + printf (") == %ld, should be %ld\n", (long) tl, (long) tk); + return 1; + } + + return 0; +} + +int main (argc, argv) int argc; - char *argv[]; + char **argv; { - int time; - int result_time; - struct tm *tmptr; - - if (argc == 1) + int status = 0; + struct tm tm, tmk, tml; + struct tm *lt; + time_t tk, tl; + char trailer; + + if ((argc == 3 || argc == 4) + && (sscanf (argv[1], "%d-%d-%d%c", + &tm.tm_year, &tm.tm_mon, &tm.tm_mday, &trailer) + == 3) + && (sscanf (argv[2], "%d:%d:%d%c", + &tm.tm_hour, &tm.tm_min, &tm.tm_sec, &trailer) + == 3)) { - long q; - - printf ("starting long test...\n"); - - for (q = 10000000; q < 1000000000; q++) + tm.tm_year -= TM_YEAR_BASE; + tm.tm_mon--; + tm.tm_isdst = argc == 3 ? -1 : atoi (argv[3]); + tmk = tm; + tl = mktime (&tmk); + lt = localtime (&tl); + if (lt) { - struct tm *tm = localtime (&q); - if ((q % 10000) == 0) { printf ("%ld\n", q); fflush (stdout); } - if (q != mktime (tm)) - { printf ("failed for %ld\n", q); fflush (stdout); } + tml = *lt; + lt = &tml; } - - printf ("test finished\n"); - - exit (0); + printf ("mktime returns %ld == ", (long) tl); + print_tm (&tmk); + printf ("\n"); + status = check_result (tl, tmk, tl, lt); } - - if (argc != 2) + else if (argc == 4 || (argc == 5 && strcmp (argv[4], "-") == 0)) { - printf ("wrong # of args\n"); - exit (0); + time_t from = atol (argv[1]); + time_t by = atol (argv[2]); + time_t to = atol (argv[3]); + + if (argc == 4) + for (tl = from; tl <= to; tl += by) + { + lt = localtime (&tl); + if (lt) + { + tmk = tml = *lt; + tk = mktime (&tmk); + status |= check_result (tk, tmk, tl, tml); + } + else + { + printf ("localtime (%ld) yields 0\n", (long) tl); + status = 1; + } + } + else + for (tl = from; tl <= to; tl += by) + { + /* Null benchmark. */ + lt = localtime (&tl); + if (lt) + { + tmk = tml = *lt; + tk = tl; + status |= check_result (tk, tmk, tl, tml); + } + else + { + printf ("localtime (%ld) yields 0\n", (long) tl); + status = 1; + } + } } - - debugging_enabled = 1; /* We want to see the info */ - - ++argv; - time = atoi (*argv); - - printf ("Time: %d %s\n", time, ctime ((time_t *) &time)); - - tmptr = localtime ((time_t *) &time); - printf ("localtime returns: "); - printtm (tmptr); - printf ("\n"); - printf ("mktime: %d\n\n", (int) mktime (tmptr)); - - tmptr->tm_sec -= 20; - tmptr->tm_min -= 20; - tmptr->tm_hour -= 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_isdst = -1; - - printf ("changed ranges: "); - printtm (tmptr); - printf ("\n\n"); - - result_time = mktime (tmptr); - printf ("\nmktime: %d\n", result_time); + else + printf ("Usage:\ +\t%s YYYY-MM-DD HH:MM:SS [ISDST] # Test given time.\n\ +\t%s FROM BY TO # Test values FROM, FROM+BY, ..., TO.\n\ +\t%s FROM BY TO - # Do not test those values (for benchmark).\n", + argv[0], argv[0], argv[0]); + + return status; } + #endif /* DEBUG */ + +/* +Local Variables: +compile-command: "gcc -DDEBUG -DHAVE_LIMITS_H -DSTDC_HEADERS -Wall -W -O -g mktime.c -o mktime" +End: +*/