NetBSD/lib/libc/time/strftime.c
christos 33d9f9e08d Welcome to tzcode 2013e:
Changes affecting API

    The 'zic' command now outputs a dummy transition when far-future
    data can't be summarized using a TZ string, and uses a 402-year
    window rather than a 400-year window.  For the current data, this
    affects only the Asia/Tehran file.  It does not affect any of the
    time stamps that this file represents, so zdump outputs the same
    information as before.  (Thanks to Andrew Main (Zefram).)

    The 'date' command has a new '-r' option, which lets you specify
    the integer time to display, a la FreeBSD.

    The 'tzselect' command has two new options '-c' and '-n', which lets you
    select a zone based on latitude and longitude.

    The 'zic' command's '-v' option now warns about constructs that
    require the new version-3 binary file format.  (Thanks to Arthur
    David Olson for the suggestion.)

    Support for floating-point time_t has been removed.
    It was always dicey, and POSIX no longer requires it.
    (Thanks to Eric Blake for suggesting to the POSIX committee to
    remove it, and thanks to Alan Barrett, Clive D.W. Feather, Andy
    Heninger, Arthur David Olson, and Alois Treindl, for reporting
    bugs and elucidating some of the corners of the old floating-point
    implementation.)

    The signatures of 'offtime', 'timeoff', and 'gtime' have been
    changed back to the old practice of using 'long' to represent UT
    offsets.  This had been inadvertently and mistakenly changed to
    'int_fast32_t'.  (Thanks to Christos Zoulos.)

    The code avoids undefined behavior on integer overflow in some
    more places, including gmtime, localtime, mktime and zdump.

  Changes affecting the zdump utility

    zdump now outputs "UT" when referring to Universal Time, not "UTC".
    "UTC" does not make sense for time stamps that predate the introduction
    of UTC, whereas "UT", a more-generic term, does.  (Thanks to Steve Allen
    for clarifying UT vs UTC.)

  Data changes affecting behavior of tzselect and similar programs

    Country code BQ is now called the more-common name "Caribbean Netherlands"
    rather than the more-official "Bonaire, St Eustatius & Saba".

    Remove from zone.tab the names America/Montreal, America/Shiprock,
    and Antarctica/South_Pole, as they are equivalent to existing
    same-country-code zones for post-1970 time stamps.  The data for
    these names are unchanged, so the names continue to work as before.

  Changes affecting code internals

    zic -c now runs way faster on 64-bit hosts when given large numbers.

    zic now uses vfprintf to avoid allocating and freeing some memory.

    tzselect now computes the list of continents from the data,
    rather than have it hard-coded.

    Minor changes pacify GCC 4.7.3 and GCC 4.8.1.

  Changes affecting the build procedure

    The 'leapseconds' file is now generated automatically from a
    new file 'leap-seconds.list', which is a copy of
    <ftp://time.nist.gov/pub/leap-seconds.list>.
    A new source file 'leapseconds.awk' implements this.
    The goal is simplification of the future maintenance of 'leapseconds'.

    When building the 'posix' or 'right' subdirectories, if the
    subdirectory would be a copy of the default subdirectory, it is
    now made a symbolic link if that is supported.  This saves about
    2 MB of file system space.

    The links America/Shiprock and Antarctica/South_Pole have been
    moved to the 'backward' file.  This affects only nondefault builds
    that omit 'backward'.

  Changes affecting documentation and commentary

    Changes to the 'tzfile' man page

      It now mentions that the binary file format may be extended in
      future versions by appending data.

      It now refers to the 'zdump' and 'zic' man pages.

    Changes to the 'zic' man page

      It lists conditions that elicit a warning with '-v'.

      It says that the behavior is unspecified when duplicate names
      are given, or if the source of one link is the target of another.

      Its examples are updated to match the latest data.

      The definition of white space has been clarified slightly.
      (Thanks to Michael Deckers.)

    Changes to the 'Theory' file

      There is a new section about the accuracy of the tz database,
      describing the many ways that errors can creep in, and
      explaining why so many of the pre-1970 time stamps are wrong or
      misleading (thanks to Steve Allen, Lester Caine, and Garrett
      Wollman for discussions that contributed to this).

      The 'Theory' file describes LMT better (this follows a
      suggestion by Guy Harris).

      It refers to the 2013 edition of POSIX rather than the 2004 edition.

      It's mentioned that excluding 'backward' should not affect the
      other data, and it suggests at least one zone.tab name per
      inhabited country (thanks to Stephen Colebourne).

      Some longstanding restrictions on names are documented, e.g.,
      'America/New_York' precludes 'America/New_York/Bronx'.

      It gives more reasons for the 1970 cutoff.

      It now mentions which time_t variants are supported, such as
      signed integer time_t.  (Thanks to Paul Goyette for reporting
      typos in an experimental version of this change.)

      (Thanks to Philip Newton for correcting typos in these changes.)

    Documentation and commentary is more careful to distinguish UT in
    general from UTC in particular.  (Thanks to Steve Allen.)

    Add a better source for the Zurich 1894 transition.
    (Thanks to Pierre-Yves Berger.)

    Update shapefile citations in tz-link.htm.  (Thanks to Guy Harris.)
2013-09-20 19:06:54 +00:00

792 lines
20 KiB
C

/* $NetBSD: strftime.c,v 1.29 2013/09/20 19:06:54 christos Exp $ */
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char elsieid[] = "@(#)strftime.c 7.64";
static char elsieid[] = "@(#)strftime.c 8.3";
#else
__RCSID("$NetBSD: strftime.c,v 1.29 2013/09/20 19:06:54 christos Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <stddef.h>
#include <locale.h>
#include "setlocale_local.h"
/*
** Based on the UCB version with the copyright notice and sccsid
** 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"
#ifdef __weak_alias
__weak_alias(strftime_l, _strftime_l)
__weak_alias(strftime_lz, _strftime_lz)
__weak_alias(strftime_z, _strftime_z)
#endif
#include "sys/localedef.h"
#define _TIME_LOCALE(loc) \
((_TimeLocale *)((loc)->part_impl[(size_t)LC_TIME]))
#define c_fmt d_t_fmt
static char * _add(const char *, char *, const char *);
static char * _conv(int, const char *, char *, const char *);
static char * _fmt(const timezone_t, const char *, const struct tm *, char *,
const char *, int *, locale_t);
static char * _yconv(int, int, int, int, char *, const char *);
extern char * tzname[];
#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_z(const timezone_t sp, char * __restrict s, size_t maxsize,
const char * __restrict format, const struct tm * __restrict t)
{
return strftime_lz(sp, s, maxsize, format, t, _current_locale());
}
size_t
strftime_lz(const timezone_t sp, char *const s, const size_t maxsize,
const char *const format, const struct tm *const t, locale_t loc)
{
char * p;
int warn;
warn = IN_NONE;
p = _fmt(sp, ((format == NULL) ? "%c" : format), t, s, s + maxsize,
&warn, loc);
#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(const timezone_t sp, const char *format, const struct tm *const t,
char *pt, const char *const ptlim, int *warnp, locale_t loc)
{
for ( ; *format; ++format) {
if (*format == '%') {
label:
switch (*++format) {
case '\0':
--format;
break;
case 'A':
pt = _add((t->tm_wday < 0 ||
t->tm_wday >= DAYSPERWEEK) ?
"?" : _TIME_LOCALE(loc)->day[t->tm_wday],
pt, ptlim);
continue;
case 'a':
pt = _add((t->tm_wday < 0 ||
t->tm_wday >= DAYSPERWEEK) ?
"?" : _TIME_LOCALE(loc)->abday[t->tm_wday],
pt, ptlim);
continue;
case 'B':
pt = _add((t->tm_mon < 0 ||
t->tm_mon >= MONSPERYEAR) ?
"?" : _TIME_LOCALE(loc)->mon[t->tm_mon],
pt, ptlim);
continue;
case 'b':
case 'h':
pt = _add((t->tm_mon < 0 ||
t->tm_mon >= MONSPERYEAR) ?
"?" : _TIME_LOCALE(loc)->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 = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
pt, ptlim);
continue;
case 'c':
{
int warn2 = IN_SOME;
pt = _fmt(sp, _TIME_LOCALE(loc)->c_fmt, t, pt,
ptlim, &warn2, loc);
if (warn2 == IN_ALL)
warn2 = IN_THIS;
if (warn2 > *warnp)
*warnp = warn2;
}
continue;
case 'D':
pt = _fmt(sp, "%m/%d/%y", t, pt, ptlim, warnp,
loc);
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(sp, "%Y-%m-%d", t, pt, ptlim, warnp,
loc);
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)) ?
_TIME_LOCALE(loc)->am_pm[1] :
_TIME_LOCALE(loc)->am_pm[0],
pt, ptlim);
continue;
case 'R':
pt = _fmt(sp, "%H:%M", t, pt, ptlim, warnp,
loc);
continue;
case 'r':
pt = _fmt(sp, _TIME_LOCALE(loc)->t_fmt_ampm, t,
pt, ptlim, warnp, loc);
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)snprintf(buf, sizeof(buf),
"%jd", (intmax_t) mkt);
else (void)snprintf(buf, sizeof(buf),
"%ju", (uintmax_t) mkt);
pt = _add(buf, pt, ptlim);
}
continue;
case 'T':
pt = _fmt(sp, "%H:%M:%S", t, pt, ptlim, warnp,
loc);
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 base;
int yday;
int wday;
int w;
year = t->tm_year;
base = TM_YEAR_BASE;
yday = t->tm_yday;
wday = t->tm_wday;
for ( ; ; ) {
int len;
int bot;
int top;
len = isleap_sum(year, base) ?
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) {
++base;
w = 1;
break;
}
if (yday >= bot) {
w = 1 + ((yday - bot) /
DAYSPERWEEK);
break;
}
--base;
yday += isleap_sum(year, base) ?
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 = _yconv(year, base, 0, 1,
pt, ptlim);
} else pt = _yconv(year, base, 1, 1,
pt, ptlim);
}
continue;
case 'v':
/*
** From Arnold Robbins' strftime version 3.0:
** "date as dd-bbb-YYYY"
** (ado, 1993-05-24)
*/
pt = _fmt(sp, "%e-%b-%Y", t, pt, ptlim, warnp,
loc);
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(sp, _TIME_LOCALE(loc)->t_fmt, t, pt,
ptlim, warnp, loc);
continue;
case 'x':
{
int warn2 = IN_SOME;
pt = _fmt(sp, _TIME_LOCALE(loc)->d_fmt, t, pt,
ptlim, &warn2, loc);
if (warn2 == IN_ALL)
warn2 = IN_THIS;
if (warn2 > *warnp)
*warnp = warn2;
}
continue;
case 'y':
*warnp = IN_ALL;
pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1,
pt, ptlim);
continue;
case 'Y':
pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1,
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((sp ?
tzgetname(sp, t->tm_isdst) :
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 UT 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 /= SECSPERMIN;
diff = (diff / MINSPERHOUR) * 100 +
(diff % MINSPERHOUR);
pt = _conv(diff, "%04d", pt, ptlim);
}
continue;
#if 0
case '+':
pt = _fmt(sp, _TIME_LOCALE(loc)->date_fmt, t,
pt, ptlim, warnp, loc);
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;
}
size_t
strftime(char * const s, const size_t maxsize,
const char * const format, const struct tm * const t)
{
tzset();
return strftime_z(NULL, s, maxsize, format, t);
}
size_t
strftime_l(char * __restrict s, size_t maxsize, const char * __restrict format,
const struct tm * __restrict t, locale_t loc)
{
tzset();
return strftime_lz(NULL, s, maxsize, format, t, loc);
}
static char *
_conv(const int n, const char *const format, char *const pt,
const char *const ptlim)
{
char buf[INT_STRLEN_MAXIMUM(int) + 1];
(void) snprintf(buf, sizeof(buf), format, n);
return _add(buf, pt, ptlim);
}
static char *
_add(const char *str, char *pt, const char *const ptlim)
{
while (pt < ptlim && (*pt = *str++) != '\0')
++pt;
return pt;
}
/*
** POSIX and the C Standard are unclear or inconsistent about
** what %C and %y do if the year is negative or exceeds 9999.
** Use the convention that %C concatenated with %y yields the
** same output as %Y, and that %Y contains at least 4 bytes,
** with more only if necessary.
*/
static char *
_yconv(const int a, const int b, const int convert_top, const int convert_yy,
char *pt, const char *const ptlim)
{
int lead;
int trail;
#define DIVISOR 100
trail = a % DIVISOR + b % DIVISOR;
lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
trail %= DIVISOR;
if (trail < 0 && lead > 0) {
trail += DIVISOR;
--lead;
} else if (lead < 0 && trail > 0) {
trail -= DIVISOR;
++lead;
}
if (convert_top) {
if (lead == 0 && trail < 0)
pt = _add("-0", pt, ptlim);
else pt = _conv(lead, "%02d", pt, ptlim);
}
if (convert_yy)
pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, ptlim);
return pt;
}
#ifdef LOCALE_HOME
static struct lc_time_T *
_loc(void)
{
static const char locale_home[] = LOCALE_HOME;
static const char lc_time[] = "LC_TIME";
static char * locale_buf;
int fd;
int oldsun; /* "...ain't got nothin' to do..." */
char * lbuf;
char * name;
char * p;
const char ** ap;
const char * plim;
char filename[FILENAME_MAX];
struct stat st;
size_t namesize;
size_t bufsize;
/*
** Use localebuf.mon[0] to signal whether locale is already set up.
*/
if (localebuf.mon[0])
return &localebuf;
name = setlocale(LC_TIME, NULL);
if (name == NULL || *name == '\0')
goto no_locale;
/*
** If the locale name is the same as our cache, use the cache.
*/
lbuf = locale_buf;
if (lbuf != NULL && strcmp(name, lbuf) == 0) {
p = lbuf;
for (ap = (const char **) &localebuf;
ap < (const char **) (&localebuf + 1);
++ap)
*ap = p += strlen(p) + 1;
return &localebuf;
}
/*
** Slurp the locale file into the cache.
*/
namesize = strlen(name) + 1;
if (sizeof filename <
((sizeof locale_home) + namesize + (sizeof lc_time)))
goto no_locale;
oldsun = 0;
(void) sprintf(filename, "%s/%s/%s", locale_home, name, lc_time);
fd = open(filename, O_RDONLY);
if (fd < 0) {
/*
** Old Sun systems have a different naming and data convention.
*/
oldsun = 1;
(void) sprintf(filename, "%s/%s/%s", locale_home,
lc_time, name);
fd = open(filename, O_RDONLY);
if (fd < 0)
goto no_locale;
}
if (fstat(fd, &st) != 0)
goto bad_locale;
if (st.st_size <= 0)
goto bad_locale;
bufsize = namesize + st.st_size;
locale_buf = NULL;
lbuf = (lbuf == NULL) ? malloc(bufsize) : realloc(lbuf, bufsize);
if (lbuf == NULL)
goto bad_locale;
(void) strcpy(lbuf, name);
p = lbuf + namesize;
plim = p + st.st_size;
if (read(fd, p, (size_t) st.st_size) != st.st_size)
goto bad_lbuf;
if (close(fd) != 0)
goto bad_lbuf;
/*
** Parse the locale file into localebuf.
*/
if (plim[-1] != '\n')
goto bad_lbuf;
for (ap = (const char **) &localebuf;
ap < (const char **) (&localebuf + 1);
++ap) {
if (p == plim)
goto bad_lbuf;
*ap = p;
while (*p != '\n')
++p;
*p++ = '\0';
}
if (oldsun) {
/*
** SunOS 4 used an obsolescent format; see localdtconv(3).
** c_fmt had the ``short format for dates and times together''
** (SunOS 4 date, "%a %b %e %T %Z %Y" in the C locale);
** date_fmt had the ``long format for dates''
** (SunOS 4 strftime %C, "%A, %B %e, %Y" in the C locale).
** Discard the latter in favor of the former.
*/
localebuf.date_fmt = localebuf.c_fmt;
}
/*
** Record the successful parse in the cache.
*/
locale_buf = lbuf;
return &localebuf;
bad_lbuf:
free(lbuf);
bad_locale:
(void) close(fd);
no_locale:
localebuf = C_time_locale;
locale_buf = NULL;
return &localebuf;
}
#endif /* defined LOCALE_HOME */