NetBSD/lib/libc/time/strftime.c

425 lines
10 KiB
C

/* $NetBSD: strftime.c,v 1.9 1999/11/05 19:21:12 erh Exp $ */
/*
* Copyright (c) 1989 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.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char *sccsid = "@(#)strftime.c 5.11 (Berkeley) 2/24/91";
#else
__RCSID("$NetBSD: strftime.c,v 1.9 1999/11/05 19:21:12 erh Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <sys/localedef.h>
#include <locale.h>
#include <string.h>
#include <tzfile.h>
#include <time.h>
static int _add __P((const char *, char **, const char *));
static int _conv __P((int, int, int, char **, const char *));
static int _secs __P((const struct tm *, char **, const char *));
static size_t _fmt __P((const char *, const struct tm *, char **,
const char *));
size_t
strftime(s, maxsize, format, t)
char *s;
size_t maxsize;
const char *format;
const struct tm *t;
{
char *pt;
tzset();
if (maxsize < 1)
return (0);
pt = s;
if (_fmt(format, t, &pt, s + maxsize)) {
*pt = '\0';
return (pt - s);
} else
return (0);
}
#define SUN_WEEK(t) (((t)->tm_yday + 7 - \
((t)->tm_wday)) / 7)
#define MON_WEEK(t) (((t)->tm_yday + 7 - \
((t)->tm_wday ? (t)->tm_wday - 1 : 6)) / 7)
static size_t
_fmt(format, t, pt, ptlim)
const char *format;
const struct tm *t;
char **pt;
const char * const ptlim;
{
for (; *format; ++format) {
if (*format == '%') {
++format;
if (*format == 'E') {
/* Alternate Era */
++format;
} else if (*format == 'O') {
/* Alternate numeric symbols */
++format;
}
switch (*format) {
case '\0':
--format;
break;
case 'A':
if (t->tm_wday < 0 || t->tm_wday > 6)
return (0);
if (!_add(_CurrentTimeLocale->day[t->tm_wday],
pt, ptlim))
return (0);
continue;
case 'a':
if (t->tm_wday < 0 || t->tm_wday > 6)
return (0);
if (!_add(_CurrentTimeLocale->abday[t->tm_wday],
pt, ptlim))
return (0);
continue;
case 'B':
if (t->tm_mon < 0 || t->tm_mon > 11)
return (0);
if (!_add(_CurrentTimeLocale->mon[t->tm_mon],
pt, ptlim))
return (0);
continue;
case 'b':
case 'h':
if (t->tm_mon < 0 || t->tm_mon > 11)
return (0);
if (!_add(_CurrentTimeLocale->abmon[t->tm_mon],
pt, ptlim))
return (0);
continue;
case 'C':
if (!_conv((t->tm_year + TM_YEAR_BASE) / 100,
2, '0', pt, ptlim))
return (0);
continue;
case 'c':
if (!_fmt(_CurrentTimeLocale->d_t_fmt, t, pt,
ptlim))
return (0);
continue;
case 'D':
if (!_fmt("%m/%d/%y", t, pt, ptlim))
return (0);
continue;
case 'd':
if (!_conv(t->tm_mday, 2, '0', pt, ptlim))
return (0);
continue;
case 'e':
if (!_conv(t->tm_mday, 2, ' ', pt, ptlim))
return (0);
continue;
case 'H':
if (!_conv(t->tm_hour, 2, '0', pt, ptlim))
return (0);
continue;
case 'I':
if (!_conv(t->tm_hour % 12 ?
t->tm_hour % 12 : 12, 2, '0', pt, ptlim))
return (0);
continue;
case 'j':
if (!_conv(t->tm_yday + 1, 3, '0', pt, ptlim))
return (0);
continue;
case 'k':
if (!_conv(t->tm_hour, 2, ' ', pt, ptlim))
return (0);
continue;
case 'l':
if (!_conv(t->tm_hour % 12 ?
t->tm_hour % 12: 12, 2, ' ', pt, ptlim))
return (0);
continue;
case 'M':
if (!_conv(t->tm_min, 2, '0', pt, ptlim))
return (0);
continue;
case 'm':
if (!_conv(t->tm_mon + 1, 2, '0', pt, ptlim))
return (0);
continue;
case 'n':
if (!_add("\n", pt, ptlim))
return (0);
continue;
case 'p':
if (!_add(_CurrentTimeLocale->am_pm[t->tm_hour
>= 12], pt, ptlim))
return (0);
continue;
case 'R':
if (!_fmt("%H:%M", t, pt, ptlim))
return (0);
continue;
case 'r':
if (!_fmt(_CurrentTimeLocale->t_fmt_ampm, t, pt,
ptlim))
return (0);
continue;
case 'S':
if (!_conv(t->tm_sec, 2, '0', pt, ptlim))
return (0);
continue;
case 's':
if (!_secs(t, pt, ptlim))
return (0);
continue;
case 'T':
if (!_fmt("%H:%M:%S", t, pt, ptlim))
return (0);
continue;
case 't':
if (!_add("\t", pt, ptlim))
return (0);
continue;
case 'U':
if (!_conv(SUN_WEEK(t), 2, '0', pt, ptlim))
return (0);
continue;
case 'u':
if (!_conv(t->tm_wday ? t->tm_wday : 7, 1, '0',
pt, ptlim))
return (0);
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') {
if (!_conv(w, 2, '0',
pt, ptlim))
return (0);
} else if (*format == 'g') {
if (!_conv(year % 100, 2, '0',
pt, ptlim))
return (0);
} else if (!_conv(year, 4, '0',
pt, ptlim))
return (0);
}
continue;
case 'W':
if (!_conv(MON_WEEK(t), 2, '0', pt, ptlim))
return (0);
continue;
case 'w':
if (!_conv(t->tm_wday, 1, '0', pt, ptlim))
return (0);
continue;
case 'x':
if (!_fmt(_CurrentTimeLocale->d_fmt, t, pt,
ptlim))
return (0);
continue;
case 'X':
if (!_fmt(_CurrentTimeLocale->t_fmt, t, pt,
ptlim))
return (0);
continue;
case 'y':
if (!_conv((t->tm_year + TM_YEAR_BASE) % 100,
2, '0', pt, ptlim))
return (0);
continue;
case 'Y':
if (!_conv((t->tm_year + TM_YEAR_BASE), 4, '0',
pt, ptlim))
return (0);
continue;
case 'Z':
if (tzname[t->tm_isdst ? 1 : 0] &&
!_add(tzname[t->tm_isdst ? 1 : 0], pt,
ptlim))
return (0);
continue;
case '%':
/*
* X311J/88-090 (4.12.3.5): if conversion char is
* undefined, behavior is undefined. Print out the
* character itself as printf(3) does.
*/
default:
break;
}
}
if (*pt == ptlim)
return (0);
*(*pt)++ = *format;
}
return (ptlim - *pt);
}
static int
_secs(t, pt, ptlim)
const struct tm *t;
char **pt;
const char * const ptlim;
{
char buf[15];
time_t s;
char *p;
struct tm tmp;
buf[sizeof (buf) - 1] = '\0';
/* Make a copy, mktime(3) modifies the tm struct. */
tmp = *t;
s = mktime(&tmp);
for (p = buf + sizeof(buf) - 2; s > 0 && p > buf; s /= 10)
*p-- = (char)(s % 10 + '0');
return (_add(++p, pt, ptlim));
}
static int
_conv(n, digits, pad, pt, ptlim)
int n, digits;
int pad;
char **pt;
const char * const ptlim;
{
char buf[10];
char *p;
buf[sizeof (buf) - 1] = '\0';
p = buf + sizeof(buf) - 2;
do {
*p-- = n % 10 + '0';
n /= 10;
--digits;
} while (n > 0 && p > buf);
while (p > buf && digits-- > 0)
*p-- = pad;
return (_add(++p, pt, ptlim));
}
static int
_add(str, pt, ptlim)
const char *str;
char **pt;
const char * const ptlim;
{
for (;; ++(*pt)) {
if (*pt == ptlim)
return (0);
if ((**pt = *str++) == '\0')
return (1);
}
}