freebsd-dev/lib/libc/string/strftime.c
1994-05-27 05:00:24 +00:00

293 lines
6.8 KiB
C

/*
* 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)strftime.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <sys/time.h>
#include <tzfile.h>
#include <string.h>
static char *afmt[] = {
"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat",
};
static char *Afmt[] = {
"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday",
"Saturday",
};
static char *bfmt[] = {
"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep",
"Oct", "Nov", "Dec",
};
static char *Bfmt[] = {
"January", "February", "March", "April", "May", "June", "July",
"August", "September", "October", "November", "December",
};
static size_t gsize;
static char *pt;
static int _add __P((char *));
static int _conv __P((int, int, int));
static int _secs __P((const struct tm *));
static size_t _fmt __P((const char *, const struct tm *));
size_t
strftime(s, maxsize, format, t)
char *s;
size_t maxsize;
const char *format;
const struct tm *t;
{
pt = s;
if ((gsize = maxsize) < 1)
return(0);
if (_fmt(format, t)) {
*pt = '\0';
return(maxsize - gsize);
}
return(0);
}
static size_t
_fmt(format, t)
register const char *format;
const struct tm *t;
{
for (; *format; ++format) {
if (*format == '%')
switch(*++format) {
case '\0':
--format;
break;
case 'A':
if (t->tm_wday < 0 || t->tm_wday > 6)
return(0);
if (!_add(Afmt[t->tm_wday]))
return(0);
continue;
case 'a':
if (t->tm_wday < 0 || t->tm_wday > 6)
return(0);
if (!_add(afmt[t->tm_wday]))
return(0);
continue;
case 'B':
if (t->tm_mon < 0 || t->tm_mon > 11)
return(0);
if (!_add(Bfmt[t->tm_mon]))
return(0);
continue;
case 'b':
case 'h':
if (t->tm_mon < 0 || t->tm_mon > 11)
return(0);
if (!_add(bfmt[t->tm_mon]))
return(0);
continue;
case 'C':
if (!_fmt("%a %b %e %H:%M:%S %Y", t))
return(0);
continue;
case 'c':
if (!_fmt("%m/%d/%y %H:%M:%S", t))
return(0);
continue;
case 'D':
if (!_fmt("%m/%d/%y", t))
return(0);
continue;
case 'd':
if (!_conv(t->tm_mday, 2, '0'))
return(0);
continue;
case 'e':
if (!_conv(t->tm_mday, 2, ' '))
return(0);
continue;
case 'H':
if (!_conv(t->tm_hour, 2, '0'))
return(0);
continue;
case 'I':
if (!_conv(t->tm_hour % 12 ?
t->tm_hour % 12 : 12, 2, '0'))
return(0);
continue;
case 'j':
if (!_conv(t->tm_yday + 1, 3, '0'))
return(0);
continue;
case 'k':
if (!_conv(t->tm_hour, 2, ' '))
return(0);
continue;
case 'l':
if (!_conv(t->tm_hour % 12 ?
t->tm_hour % 12 : 12, 2, ' '))
return(0);
continue;
case 'M':
if (!_conv(t->tm_min, 2, '0'))
return(0);
continue;
case 'm':
if (!_conv(t->tm_mon + 1, 2, '0'))
return(0);
continue;
case 'n':
if (!_add("\n"))
return(0);
continue;
case 'p':
if (!_add(t->tm_hour >= 12 ? "PM" : "AM"))
return(0);
continue;
case 'R':
if (!_fmt("%H:%M", t))
return(0);
continue;
case 'r':
if (!_fmt("%I:%M:%S %p", t))
return(0);
continue;
case 'S':
if (!_conv(t->tm_sec, 2, '0'))
return(0);
continue;
case 's':
if (!_secs(t))
return(0);
continue;
case 'T':
case 'X':
if (!_fmt("%H:%M:%S", t))
return(0);
continue;
case 't':
if (!_add("\t"))
return(0);
continue;
case 'U':
if (!_conv((t->tm_yday + 7 - t->tm_wday) / 7,
2, '0'))
return(0);
continue;
case 'W':
if (!_conv((t->tm_yday + 7 -
(t->tm_wday ? (t->tm_wday - 1) : 6))
/ 7, 2, '0'))
return(0);
continue;
case 'w':
if (!_conv(t->tm_wday, 1, '0'))
return(0);
continue;
case 'x':
if (!_fmt("%m/%d/%y", t))
return(0);
continue;
case 'y':
if (!_conv((t->tm_year + TM_YEAR_BASE)
% 100, 2, '0'))
return(0);
continue;
case 'Y':
if (!_conv(t->tm_year + TM_YEAR_BASE, 4, '0'))
return(0);
continue;
case 'Z':
if (!t->tm_zone || !_add(t->tm_zone))
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 (!gsize--)
return(0);
*pt++ = *format;
}
return(gsize);
}
static int
_secs(t)
const struct tm *t;
{
static char buf[15];
register time_t s;
register char *p;
struct tm tmp;
/* 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-- = s % 10 + '0';
return(_add(++p));
}
static int
_conv(n, digits, pad)
int n, digits, pad;
{
static char buf[10];
register char *p;
for (p = buf + sizeof(buf) - 2; n > 0 && p > buf; n /= 10, --digits)
*p-- = n % 10 + '0';
while (p > buf && digits-- > 0)
*p-- = pad;
return(_add(++p));
}
static int
_add(str)
register char *str;
{
for (;; ++pt, --gsize) {
if (!gsize)
return(0);
if (!(*pt = *str++))
return(1);
}
}