freebsd-skq/lib/libc/stdtime/strftime.c
joerg 3322d89b34 There were so far only 42 different conversion specifications in
strftime(3), add another one. :)  %z yields the local timezone's offset
in hours and minutes, as used in RFC822 headers.  There's a precedence
for this in Lunux' libc, and Internet software (like Perl scripts)
start using it.

OKed by (wrt. the code freeze): jkh
2000-01-28 17:40:42 +00:00

459 lines
11 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.
*/
#ifdef LIBC_RCS
static const char rcsid[] =
"$FreeBSD$";
#endif
#ifndef lint
#ifndef NOID
static const char elsieid[] = "@(#)strftime.c 7.38";
/*
** 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 "private.h"
#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 <sys/stat.h>
#include "timelocal.h"
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 *));
size_t strftime P((char *, size_t, const char *, const struct tm *));
extern char * tzname[];
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;
tzset();
p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize);
if (p == s + maxsize)
return 0;
*p = '\0';
return p - s;
}
static char *
_fmt(format, t, pt, ptlim)
const char *format;
const struct tm *const t;
char *pt;
const char *const ptlim;
{
int Ealternative, Oalternative;
for ( ; *format; ++format) {
if (*format == '%') {
Ealternative = 0;
Oalternative = 0;
label:
switch (*++format) {
case '\0':
--format;
break;
case 'A':
pt = _add((t->tm_wday < 0 || t->tm_wday > 6) ?
"?" : Locale->weekday[t->tm_wday],
pt, ptlim);
continue;
case 'a':
pt = _add((t->tm_wday < 0 || t->tm_wday > 6) ?
"?" : Locale->wday[t->tm_wday],
pt, ptlim);
continue;
case 'B':
pt = _add((t->tm_mon < 0 || t->tm_mon > 11) ?
"?" : (Oalternative ? Locale->alt_month :
Locale->month)[t->tm_mon],
pt, ptlim);
continue;
case 'b':
case 'h':
pt = _add((t->tm_mon < 0 || t->tm_mon > 11) ?
"?" : Locale->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, 5/24/93)
*/
pt = _conv((t->tm_year + TM_YEAR_BASE) / 100,
"%02d", pt, ptlim);
continue;
case 'c':
pt = _fmt(Locale->c_fmt, t, pt, ptlim);
continue;
case 'D':
pt = _fmt("%m/%d/%y", t, pt, ptlim);
continue;
case 'd':
pt = _conv(t->tm_mday, "%02d", pt, ptlim);
continue;
case 'E':
if (Ealternative || Oalternative)
break;
Ealternative++;
goto label;
case 'O':
/*
** POSIX locale extensions, a la
** Arnold Robbins' strftime version 3.0.
** 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.
** (ado, 5/24/93)
**
** FreeBSD extensions
** %OB %Ef %EF
*/
if (Ealternative || Oalternative)
break;
Oalternative++;
goto label;
case 'e':
pt = _conv(t->tm_mday, "%2d", pt, ptlim);
continue;
case 'f':
if (!Ealternative)
break;
pt = _fmt(Locale->Ef_fmt, t, pt, ptlim);
continue;
case 'F':
if (!Ealternative)
break;
pt = _fmt(Locale->EF_fmt, t, pt, ptlim);
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, 5/24/93)
*/
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, 5/24/93)
*/
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 >= 12) ?
Locale->pm :
Locale->am,
pt, ptlim);
continue;
case 'R':
pt = _fmt("%H:%M", t, pt, ptlim);
continue;
case 'r':
pt = _fmt("%I:%M:%S %p", t, pt, ptlim);
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);
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);
continue;
case 't':
pt = _add("\t", pt, ptlim);
continue;
case 'U':
pt = _conv((t->tm_yday + 7 - t->tm_wday) / 7,
"%02d", pt, ptlim);
continue;
case 'u':
/*
** From Arnold Robbins' strftime version 3.0:
** "ISO 8601: Weekday as a decimal number
** [1 (Monday) - 7]"
** (ado, 5/24/93)
*/
pt = _conv((t->tm_wday == 0) ? 7 : 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') {
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, 5/24/93)
*/
pt = _fmt("%e-%b-%Y", t, pt, ptlim);
continue;
case 'W':
pt = _conv((t->tm_yday + 7 -
(t->tm_wday ?
(t->tm_wday - 1) : 6)) / 7,
"%02d", pt, ptlim);
continue;
case 'w':
pt = _conv(t->tm_wday, "%d", pt, ptlim);
continue;
case 'X':
pt = _fmt(Locale->X_fmt, t, pt, ptlim);
continue;
case 'x':
pt = _fmt(Locale->x_fmt, t, pt, ptlim);
continue;
case 'y':
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':
if (t->tm_zone != NULL)
pt = _add(t->tm_zone, pt, ptlim);
else
if (t->tm_isdst == 0 || t->tm_isdst == 1) {
pt = _add(tzname[t->tm_isdst],
pt, ptlim);
} else pt = _add("?", pt, ptlim);
continue;
case 'z':
{
long absoff;
if (t->tm_gmtoff >= 0) {
absoff = t->tm_gmtoff;
pt = _add("+", pt, ptlim);
} else {
absoff = -t->tm_gmtoff;
pt = _add("-", pt, ptlim);
}
pt = _conv(absoff / 3600, "%02d",
pt, ptlim);
pt = _conv((absoff % 3600) / 60, "%02d",
pt, ptlim);
};
continue;
case '+':
pt = _fmt(Locale->date_fmt, t, pt, ptlim);
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) 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;
}