freebsd-dev/lib/libc/stdtime/strftime.c
2009-06-09 09:02:58 +00:00

635 lines
16 KiB
C

/*
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef lint
#ifndef NOID
static const char elsieid[] = "@(#)strftime.3 8.3";
/*
** Based on the UCB version with the ID appearing below.
** This is ANSIish only when "multibyte character == plain character".
*/
#endif /* !defined NOID */
#endif /* !defined lint */
#include "namespace.h"
#include "private.h"
#if defined(LIBC_SCCS) && !defined(lint)
static const char sccsid[] = "@(#)strftime.c 5.4 (Berkeley) 3/14/89";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "tzfile.h"
#include <fcntl.h>
#include <sys/stat.h>
#include "un-namespace.h"
#include "timelocal.h"
static char * _add(const char *, char *, const char *);
static char * _conv(int, const char *, char *, const char *);
static char * _fmt(const char *, const struct tm *, char *, const char *,
int *);
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
#define PAD_DEFAULT 0
#define PAD_LESS 1
#define PAD_SPACE 2
#define PAD_ZERO 3
static const char* fmt_padding[][4] = {
/* DEFAULT, LESS, SPACE, ZERO */
#define PAD_FMT_MONTHDAY 0
#define PAD_FMT_HMS 0
#define PAD_FMT_CENTURY 0
#define PAD_FMT_SHORTYEAR 0
#define PAD_FMT_MONTH 0
#define PAD_FMT_WEEKOFYEAR 0
#define PAD_FMT_DAYOFMONTH 0
{ "%02d", "%d", "%2d", "%02d" },
#define PAD_FMT_SDAYOFMONTH 1
#define PAD_FMT_SHMS 1
{ "%2d", "%d", "%2d", "%02d" },
#define PAD_FMT_DAYOFYEAR 2
{ "%03d", "%d", "%3d", "%03d" },
#define PAD_FMT_YEAR 3
{ "%04d", "%d", "%4d", "%04d" }
};
size_t
strftime(char * __restrict s, size_t maxsize, const char * __restrict format,
const struct tm * __restrict 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;
{
int Ealternative, Oalternative, PadIndex;
struct lc_time_T *tptr = __get_current_time_locale();
for ( ; *format; ++format) {
if (*format == '%') {
Ealternative = 0;
Oalternative = 0;
PadIndex = PAD_DEFAULT;
label:
switch (*++format) {
case '\0':
--format;
break;
case 'A':
pt = _add((t->tm_wday < 0 ||
t->tm_wday >= DAYSPERWEEK) ?
"?" : tptr->weekday[t->tm_wday],
pt, ptlim);
continue;
case 'a':
pt = _add((t->tm_wday < 0 ||
t->tm_wday >= DAYSPERWEEK) ?
"?" : tptr->wday[t->tm_wday],
pt, ptlim);
continue;
case 'B':
pt = _add((t->tm_mon < 0 ||
t->tm_mon >= MONSPERYEAR) ?
"?" : (Oalternative ? tptr->alt_month :
tptr->month)[t->tm_mon],
pt, ptlim);
continue;
case 'b':
case 'h':
pt = _add((t->tm_mon < 0 ||
t->tm_mon >= MONSPERYEAR) ?
"?" : tptr->mon[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(tptr->c_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, fmt_padding[PAD_FMT_DAYOFMONTH][PadIndex],
pt, ptlim);
continue;
case 'E':
if (Ealternative || Oalternative)
break;
Ealternative++;
goto label;
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.
**
** FreeBSD extension
** %OB
*/
if (Ealternative || Oalternative)
break;
Oalternative++;
goto label;
case 'e':
pt = _conv(t->tm_mday,
fmt_padding[PAD_FMT_SDAYOFMONTH][PadIndex], pt, ptlim);
continue;
case 'F':
pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp);
continue;
case 'H':
pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_HMS][PadIndex],
pt, ptlim);
continue;
case 'I':
pt = _conv((t->tm_hour % 12) ?
(t->tm_hour % 12) : 12,
fmt_padding[PAD_FMT_HMS][PadIndex], pt, ptlim);
continue;
case 'j':
pt = _conv(t->tm_yday + 1,
fmt_padding[PAD_FMT_DAYOFYEAR][PadIndex], 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, fmt_padding[PAD_FMT_SHMS][PadIndex],
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,
fmt_padding[PAD_FMT_SHMS][PadIndex], pt, ptlim);
continue;
case 'M':
pt = _conv(t->tm_min, fmt_padding[PAD_FMT_HMS][PadIndex],
pt, ptlim);
continue;
case 'm':
pt = _conv(t->tm_mon + 1,
fmt_padding[PAD_FMT_MONTH][PadIndex], pt, ptlim);
continue;
case 'n':
pt = _add("\n", pt, ptlim);
continue;
case 'p':
pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
tptr->pm :
tptr->am,
pt, ptlim);
continue;
case 'R':
pt = _fmt("%H:%M", t, pt, ptlim, warnp);
continue;
case 'r':
pt = _fmt(tptr->ampm_fmt, t, pt, ptlim,
warnp);
continue;
case 'S':
pt = _conv(t->tm_sec, fmt_padding[PAD_FMT_HMS][PadIndex],
pt, ptlim);
continue;
case 's':
{
struct tm tm;
char buf[INT_STRLEN_MAXIMUM(
time_t) + 1];
time_t mkt;
tm = *t;
mkt = mktime(&tm);
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,
fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], 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, fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex],
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("%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,
fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], pt, ptlim);
continue;
case 'w':
pt = _conv(t->tm_wday, "%d", pt, ptlim);
continue;
case 'X':
pt = _fmt(tptr->X_fmt, t, pt, ptlim, warnp);
continue;
case 'x':
{
int warn2 = IN_SOME;
pt = _fmt(tptr->x_fmt, t, pt, ptlim, &warn2);
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(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 = 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.
*/
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 */
#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,
fmt_padding[PAD_FMT_YEAR][PadIndex], pt, ptlim);
}
continue;
case '+':
pt = _fmt(tptr->date_fmt, t, pt, ptlim,
warnp);
continue;
case '-':
if (PadIndex != PAD_DEFAULT)
break;
PadIndex = PAD_LESS;
goto label;
case '_':
if (PadIndex != PAD_DEFAULT)
break;
PadIndex = PAD_SPACE;
goto label;
case '0':
if (PadIndex != PAD_DEFAULT)
break;
PadIndex = PAD_ZERO;
goto label;
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;
}
/*
** 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(a, b, convert_top, convert_yy, pt, ptlim)
const int a;
const int b;
const int convert_top;
const int convert_yy;
char * pt;
const char * const ptlim;
{
register int lead;
register 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;
}