NetBSD/lib/libc/time/strftime.c

595 lines
15 KiB
C

/* $NetBSD: strftime.c,v 1.17 2006/03/22 00:11:28 christos Exp $ */
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char elsieid[] = "@(#)strftime.c 7.64";
#else
__RCSID("$NetBSD: strftime.c,v 1.17 2006/03/22 00:11:28 christos Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
/*
** Based on the UCB version with the ID appearing below.
** This is ANSIish only when "multibyte character == plain character".
*/
#include "private.h"
/*
** We don't use these extensions in strftime operation even when
** supported by the local tzcode configuration. A strictly
** conforming C application may leave them in undefined state.
*/
#ifdef _LIBC
#undef TM_ZONE
#undef TM_GMTOFF
#endif
/*
** Copyright (c) 1989, 1993
** The Regents of the University of California. All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
** 1. Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in the
** documentation and/or other materials provided with the distribution.
** 3. All advertising materials mentioning features or use of this software
** must display the following acknowledgement:
** This product includes software developed by the University of
** California, Berkeley and its contributors.
** 4. Neither the name of the University nor the names of its contributors
** may be used to endorse or promote products derived from this software
** without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
** ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
** SUCH DAMAGE.
*/
#ifndef LIBC_SCCS
#ifndef lint
static const char sccsid[] = "@(#)strftime.c 5.4 (Berkeley) 3/14/89";
#endif /* !defined lint */
#endif /* !defined LIBC_SCCS */
#include "tzfile.h"
#include "fcntl.h"
#include "locale.h"
#include "sys/localedef.h"
#define Locale _CurrentTimeLocale
static char * _add P((const char *, char *, const char *));
static char * _conv P((int, const char *, char *, const char *));
static char * _fmt P((const char *, const struct tm *, char *, const char *, int *));
#define NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
#ifndef YEAR_2000_NAME
#define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS"
#endif /* !defined YEAR_2000_NAME */
#define IN_NONE 0
#define IN_SOME 1
#define IN_THIS 2
#define IN_ALL 3
size_t
strftime(s, maxsize, format, t)
char * const s;
const size_t maxsize;
const char * const format;
const struct tm * const t;
{
char * p;
int warn;
tzset();
warn = IN_NONE;
p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn);
#ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) {
(void) fprintf(stderr, "\n");
if (format == NULL)
(void) fprintf(stderr, "NULL strftime format ");
else (void) fprintf(stderr, "strftime format \"%s\" ",
format);
(void) fprintf(stderr, "yields only two digits of years in ");
if (warn == IN_SOME)
(void) fprintf(stderr, "some locales");
else if (warn == IN_THIS)
(void) fprintf(stderr, "the current locale");
else (void) fprintf(stderr, "all locales");
(void) fprintf(stderr, "\n");
}
#endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */
if (p == s + maxsize)
return 0;
*p = '\0';
return p - s;
}
static char *
_fmt(format, t, pt, ptlim, warnp)
const char * format;
const struct tm * const t;
char * pt;
const char * const ptlim;
int * warnp;
{
for ( ; *format; ++format) {
if (*format == '%') {
label:
switch (*++format) {
case '\0':
--format;
break;
case 'A':
pt = _add((t->tm_wday < 0 ||
t->tm_wday >= DAYSPERWEEK) ?
"?" : Locale->day[t->tm_wday],
pt, ptlim);
continue;
case 'a':
pt = _add((t->tm_wday < 0 ||
t->tm_wday >= DAYSPERWEEK) ?
"?" : Locale->abday[t->tm_wday],
pt, ptlim);
continue;
case 'B':
pt = _add((t->tm_mon < 0 ||
t->tm_mon >= MONSPERYEAR) ?
"?" : Locale->mon[t->tm_mon],
pt, ptlim);
continue;
case 'b':
case 'h':
pt = _add((t->tm_mon < 0 ||
t->tm_mon >= MONSPERYEAR) ?
"?" : Locale->abmon[t->tm_mon],
pt, ptlim);
continue;
case 'C':
/*
** %C used to do a...
** _fmt("%a %b %e %X %Y", t);
** ...whereas now POSIX 1003.2 calls for
** something completely different.
** (ado, 1993-05-24)
*/
pt = _conv((t->tm_year + TM_YEAR_BASE) / 100,
"%02d", pt, ptlim);
continue;
case 'c':
{
int warn2 = IN_SOME;
pt = _fmt(Locale->d_t_fmt, t, pt, ptlim, &warn2);
if (warn2 == IN_ALL)
warn2 = IN_THIS;
if (warn2 > *warnp)
*warnp = warn2;
}
continue;
case 'D':
pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp);
continue;
case 'd':
pt = _conv(t->tm_mday, "%02d", pt, ptlim);
continue;
case 'E':
case 'O':
/*
** C99 locale modifiers.
** The sequences
** %Ec %EC %Ex %EX %Ey %EY
** %Od %oe %OH %OI %Om %OM
** %OS %Ou %OU %OV %Ow %OW %Oy
** are supposed to provide alternate
** representations.
*/
goto label;
case 'e':
pt = _conv(t->tm_mday, "%2d", pt, ptlim);
continue;
case 'F':
pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp);
continue;
case 'H':
pt = _conv(t->tm_hour, "%02d", pt, ptlim);
continue;
case 'I':
pt = _conv((t->tm_hour % 12) ?
(t->tm_hour % 12) : 12,
"%02d", pt, ptlim);
continue;
case 'j':
pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim);
continue;
case 'k':
/*
** This used to be...
** _conv(t->tm_hour % 12 ?
** t->tm_hour % 12 : 12, 2, ' ');
** ...and has been changed to the below to
** match SunOS 4.1.1 and Arnold Robbins'
** strftime version 3.0. That is, "%k" and
** "%l" have been swapped.
** (ado, 1993-05-24)
*/
pt = _conv(t->tm_hour, "%2d", pt, ptlim);
continue;
#ifdef KITCHEN_SINK
case 'K':
/*
** After all this time, still unclaimed!
*/
pt = _add("kitchen sink", pt, ptlim);
continue;
#endif /* defined KITCHEN_SINK */
case 'l':
/*
** This used to be...
** _conv(t->tm_hour, 2, ' ');
** ...and has been changed to the below to
** match SunOS 4.1.1 and Arnold Robbin's
** strftime version 3.0. That is, "%k" and
** "%l" have been swapped.
** (ado, 1993-05-24)
*/
pt = _conv((t->tm_hour % 12) ?
(t->tm_hour % 12) : 12,
"%2d", pt, ptlim);
continue;
case 'M':
pt = _conv(t->tm_min, "%02d", pt, ptlim);
continue;
case 'm':
pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim);
continue;
case 'n':
pt = _add("\n", pt, ptlim);
continue;
case 'p':
pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
Locale->am_pm[1] :
Locale->am_pm[0],
pt, ptlim);
continue;
case 'R':
pt = _fmt("%H:%M", t, pt, ptlim, warnp);
continue;
case 'r':
pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp);
continue;
case 'S':
pt = _conv(t->tm_sec, "%02d", pt, ptlim);
continue;
case 's':
{
struct tm tm;
char buf[INT_STRLEN_MAXIMUM(
time_t) + 1];
time_t mkt;
tm = *t;
mkt = mktime(&tm);
/* CONSTCOND */
if (TYPE_SIGNED(time_t))
(void) sprintf(buf, "%ld",
(long) mkt);
else (void) sprintf(buf, "%lu",
(unsigned long) mkt);
pt = _add(buf, pt, ptlim);
}
continue;
case 'T':
pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp);
continue;
case 't':
pt = _add("\t", pt, ptlim);
continue;
case 'U':
pt = _conv((t->tm_yday + DAYSPERWEEK -
t->tm_wday) / DAYSPERWEEK,
"%02d", pt, ptlim);
continue;
case 'u':
/*
** From Arnold Robbins' strftime version 3.0:
** "ISO 8601: Weekday as a decimal number
** [1 (Monday) - 7]"
** (ado, 1993-05-24)
*/
pt = _conv((t->tm_wday == 0) ?
DAYSPERWEEK : t->tm_wday,
"%d", pt, ptlim);
continue;
case 'V': /* ISO 8601 week number */
case 'G': /* ISO 8601 year (four digits) */
case 'g': /* ISO 8601 year (two digits) */
/*
** From Arnold Robbins' strftime version 3.0: "the week number of the
** year (the first Monday as the first day of week 1) as a decimal number
** (01-53)."
** (ado, 1993-05-24)
**
** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
** "Week 01 of a year is per definition the first week which has the
** Thursday in this year, which is equivalent to the week which contains
** the fourth day of January. In other words, the first week of a new year
** is the week which has the majority of its days in the new year. Week 01
** might also contain days from the previous year and the week before week
** 01 of a year is the last week (52 or 53) of the previous year even if
** it contains days from the new year. A week starts with Monday (day 1)
** and ends with Sunday (day 7). For example, the first week of the year
** 1997 lasts from 1996-12-30 to 1997-01-05..."
** (ado, 1996-01-02)
*/
{
int year;
int yday;
int wday;
int w;
year = t->tm_year + TM_YEAR_BASE;
yday = t->tm_yday;
wday = t->tm_wday;
for ( ; ; ) {
int len;
int bot;
int top;
len = isleap(year) ?
DAYSPERLYEAR :
DAYSPERNYEAR;
/*
** What yday (-3 ... 3) does
** the ISO year begin on?
*/
bot = ((yday + 11 - wday) %
DAYSPERWEEK) - 3;
/*
** What yday does the NEXT
** ISO year begin on?
*/
top = bot -
(len % DAYSPERWEEK);
if (top < -3)
top += DAYSPERWEEK;
top += len;
if (yday >= top) {
++year;
w = 1;
break;
}
if (yday >= bot) {
w = 1 + ((yday - bot) /
DAYSPERWEEK);
break;
}
--year;
yday += isleap(year) ?
DAYSPERLYEAR :
DAYSPERNYEAR;
}
#ifdef XPG4_1994_04_09
if ((w == 52
&& t->tm_mon == TM_JANUARY)
|| (w == 1
&& t->tm_mon == TM_DECEMBER))
w = 53;
#endif /* defined XPG4_1994_04_09 */
if (*format == 'V')
pt = _conv(w, "%02d",
pt, ptlim);
else if (*format == 'g') {
*warnp = IN_ALL;
pt = _conv(year % 100, "%02d",
pt, ptlim);
} else pt = _conv(year, "%04d",
pt, ptlim);
}
continue;
case 'v':
/*
** From Arnold Robbins' strftime version 3.0:
** "date as dd-bbb-YYYY"
** (ado, 1993-05-24)
*/
pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp);
continue;
case 'W':
pt = _conv((t->tm_yday + DAYSPERWEEK -
(t->tm_wday ?
(t->tm_wday - 1) :
(DAYSPERWEEK - 1))) / DAYSPERWEEK,
"%02d", pt, ptlim);
continue;
case 'w':
pt = _conv(t->tm_wday, "%d", pt, ptlim);
continue;
case 'X':
pt = _fmt(Locale->t_fmt, t, pt, ptlim, warnp);
continue;
case 'x':
{
int warn2 = IN_SOME;
pt = _fmt(Locale->d_fmt, t, pt, ptlim, &warn2);
if (warn2 == IN_ALL)
warn2 = IN_THIS;
if (warn2 > *warnp)
*warnp = warn2;
}
continue;
case 'y':
*warnp = IN_ALL;
pt = _conv((t->tm_year + TM_YEAR_BASE) % 100,
"%02d", pt, ptlim);
continue;
case 'Y':
pt = _conv(t->tm_year + TM_YEAR_BASE, "%04d",
pt, ptlim);
continue;
case 'Z':
#ifdef TM_ZONE
if (t->TM_ZONE != NULL)
pt = _add(t->TM_ZONE, pt, ptlim);
else
#endif /* defined TM_ZONE */
if (t->tm_isdst >= 0)
pt = _add(tzname[t->tm_isdst != 0],
pt, ptlim);
/*
** C99 says that %Z must be replaced by the
** empty string if the time zone is not
** determinable.
*/
continue;
case 'z':
{
int diff;
char const * sign;
if (t->tm_isdst < 0)
continue;
#ifdef TM_GMTOFF
diff = (int)t->TM_GMTOFF;
#else /* !defined TM_GMTOFF */
/*
** C99 says that the UTC offset must
** be computed by looking only at
** tm_isdst. This requirement is
** incorrect, since it means the code
** must rely on magic (in this case
** altzone and timezone), and the
** magic might not have the correct
** offset. Doing things correctly is
** tricky and requires disobeying C99;
** see GNU C strftime for details.
** For now, punt and conform to the
** standard, even though it's incorrect.
**
** C99 says that %z must be replaced by the
** empty string if the time zone is not
** determinable, so output nothing if the
** appropriate variables are not available.
*/
#ifndef STD_INSPIRED
if (t->tm_isdst == 0)
#ifdef USG_COMPAT
diff = -timezone;
#else /* !defined USG_COMPAT */
continue;
#endif /* !defined USG_COMPAT */
else
#ifdef ALTZONE
diff = -altzone;
#else /* !defined ALTZONE */
continue;
#endif /* !defined ALTZONE */
#else /* defined STD_INSPIRED */
{
struct tm tmp;
time_t lct, gct;
/*
** Get calendar time from t
** being treated as local.
*/
tmp = *t; /* mktime discards const */
lct = mktime(&tmp);
if (lct == (time_t)-1)
continue;
/*
** Get calendar time from t
** being treated as GMT.
**/
tmp = *t; /* mktime discards const */
gct = timegm(&tmp);
if (gct == (time_t)-1)
continue;
/* LINTED difference will fit int */
diff = (intmax_t)gct - (intmax_t)lct;
}
#endif /* defined STD_INSPIRED */
#endif /* !defined TM_GMTOFF */
if (diff < 0) {
sign = "-";
diff = -diff;
} else sign = "+";
pt = _add(sign, pt, ptlim);
diff /= 60;
pt = _conv((diff/60)*100 + diff%60,
"%04d", pt, ptlim);
}
continue;
#if 0
case '+':
pt = _fmt(Locale->date_fmt, t, pt, ptlim,
warnp);
continue;
#endif
case '%':
/*
** X311J/88-090 (4.12.3.5): if conversion char is
** undefined, behavior is undefined. Print out the
** character itself as printf(3) also does.
*/
default:
break;
}
}
if (pt == ptlim)
break;
*pt++ = *format;
}
return pt;
}
static char *
_conv(n, format, pt, ptlim)
const int n;
const char * const format;
char * const pt;
const char * const ptlim;
{
char buf[INT_STRLEN_MAXIMUM(int) + 1];
(void) sprintf(buf, format, n);
return _add(buf, pt, ptlim);
}
static char *
_add(str, pt, ptlim)
const char * str;
char * pt;
const char * const ptlim;
{
while (pt < ptlim && (*pt = *str++) != '\0')
++pt;
return pt;
}