NetBSD/lib/libc/time/strptime.c
itohy 7daefc5a5a Passing "char" values to ctype(3) functions is problematic.
If an argument of a ctype function is outside "unsigned char"
and if it is not EOF, the behavior is undefined.

The isascii(3) is the sole exception of above and it was used to
be used to check a value was valid for other ctype functions in
ancient systems.  On modern systems, the ctype functions take
all values of "unsigned char", and this check is obsolete and
even wrong for non-ASCII systems.  However, we leave the isascii()
untouched for now, so as not to change the current behavior.
2000-07-07 08:03:36 +00:00

395 lines
9.2 KiB
C

/* $NetBSD: strptime.c,v 1.20 2000/07/07 08:03:41 itohy Exp $ */
/*-
* Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code was contributed to The NetBSD Foundation by Klaus Klein.
*
* 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 NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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)
__RCSID("$NetBSD: strptime.c,v 1.20 2000/07/07 08:03:41 itohy Exp $");
#endif
#include "namespace.h"
#include <sys/localedef.h>
#include <ctype.h>
#include <locale.h>
#include <string.h>
#include <time.h>
#include <tzfile.h>
#ifdef __weak_alias
__weak_alias(strptime,_strptime)
#endif
#define _ctloc(x) __CONCAT(_CurrentTimeLocale->,x)
/*
* We do not implement alternate representations. However, we always
* check whether a given modifier is allowed for a certain conversion.
*/
#define ALT_E 0x01
#define ALT_O 0x02
#define LEGAL_ALT(x) { if (alt_format & ~(x)) return (0); }
static int conv_num __P((const unsigned char **, int *, int, int));
char *
strptime(buf, fmt, tm)
const char *buf, *fmt;
struct tm *tm;
{
unsigned char c;
const unsigned char *bp;
size_t len = 0;
int alt_format, i, split_year = 0;
bp = buf;
while ((c = *fmt) != '\0') {
/* Clear `alternate' modifier prior to new conversion. */
alt_format = 0;
/* Eat up white-space. */
if (isspace(c)) {
while (isspace(*bp))
bp++;
fmt++;
continue;
}
if ((c = *fmt++) != '%')
goto literal;
again: switch (c = *fmt++) {
case '%': /* "%%" is converted to "%". */
literal:
if (c != *bp++)
return (0);
break;
/*
* "Alternative" modifiers. Just set the appropriate flag
* and start over again.
*/
case 'E': /* "%E?" alternative conversion modifier. */
LEGAL_ALT(0);
alt_format |= ALT_E;
goto again;
case 'O': /* "%O?" alternative conversion modifier. */
LEGAL_ALT(0);
alt_format |= ALT_O;
goto again;
/*
* "Complex" conversion rules, implemented through recursion.
*/
case 'c': /* Date and time, using the locale's format. */
LEGAL_ALT(ALT_E);
if (!(bp = strptime(bp, _ctloc(d_t_fmt), tm)))
return (0);
break;
case 'D': /* The date as "%m/%d/%y". */
LEGAL_ALT(0);
if (!(bp = strptime(bp, "%m/%d/%y", tm)))
return (0);
break;
case 'R': /* The time as "%H:%M". */
LEGAL_ALT(0);
if (!(bp = strptime(bp, "%H:%M", tm)))
return (0);
break;
case 'r': /* The time in 12-hour clock representation. */
LEGAL_ALT(0);
if (!(bp = strptime(bp, _ctloc(t_fmt_ampm), tm)))
return (0);
break;
case 'T': /* The time as "%H:%M:%S". */
LEGAL_ALT(0);
if (!(bp = strptime(bp, "%H:%M:%S", tm)))
return (0);
break;
case 'X': /* The time, using the locale's format. */
LEGAL_ALT(ALT_E);
if (!(bp = strptime(bp, _ctloc(t_fmt), tm)))
return (0);
break;
case 'x': /* The date, using the locale's format. */
LEGAL_ALT(ALT_E);
if (!(bp = strptime(bp, _ctloc(d_fmt), tm)))
return (0);
break;
/*
* "Elementary" conversion rules.
*/
case 'A': /* The day of week, using the locale's form. */
case 'a':
LEGAL_ALT(0);
for (i = 0; i < 7; i++) {
/* Full name. */
len = strlen(_ctloc(day[i]));
if (strncasecmp(_ctloc(day[i]), bp, len) == 0)
break;
/* Abbreviated name. */
len = strlen(_ctloc(abday[i]));
if (strncasecmp(_ctloc(abday[i]), bp, len) == 0)
break;
}
/* Nothing matched. */
if (i == 7)
return (0);
tm->tm_wday = i;
bp += len;
break;
case 'B': /* The month, using the locale's form. */
case 'b':
case 'h':
LEGAL_ALT(0);
for (i = 0; i < 12; i++) {
/* Full name. */
len = strlen(_ctloc(mon[i]));
if (strncasecmp(_ctloc(mon[i]), bp, len) == 0)
break;
/* Abbreviated name. */
len = strlen(_ctloc(abmon[i]));
if (strncasecmp(_ctloc(abmon[i]), bp, len) == 0)
break;
}
/* Nothing matched. */
if (i == 12)
return (0);
tm->tm_mon = i;
bp += len;
break;
case 'C': /* The century number. */
LEGAL_ALT(ALT_E);
if (!(conv_num(&bp, &i, 0, 99)))
return (0);
if (split_year) {
tm->tm_year = (tm->tm_year % 100) + (i * 100);
} else {
tm->tm_year = i * 100;
split_year = 1;
}
break;
case 'd': /* The day of month. */
case 'e':
LEGAL_ALT(ALT_O);
if (!(conv_num(&bp, &tm->tm_mday, 1, 31)))
return (0);
break;
case 'k': /* The hour (24-hour clock representation). */
LEGAL_ALT(0);
/* FALLTHROUGH */
case 'H':
LEGAL_ALT(ALT_O);
if (!(conv_num(&bp, &tm->tm_hour, 0, 23)))
return (0);
break;
case 'l': /* The hour (12-hour clock representation). */
LEGAL_ALT(0);
/* FALLTHROUGH */
case 'I':
LEGAL_ALT(ALT_O);
if (!(conv_num(&bp, &tm->tm_hour, 1, 12)))
return (0);
if (tm->tm_hour == 12)
tm->tm_hour = 0;
break;
case 'j': /* The day of year. */
LEGAL_ALT(0);
if (!(conv_num(&bp, &i, 1, 366)))
return (0);
tm->tm_yday = i - 1;
break;
case 'M': /* The minute. */
LEGAL_ALT(ALT_O);
if (!(conv_num(&bp, &tm->tm_min, 0, 59)))
return (0);
break;
case 'm': /* The month. */
LEGAL_ALT(ALT_O);
if (!(conv_num(&bp, &i, 1, 12)))
return (0);
tm->tm_mon = i - 1;
break;
case 'p': /* The locale's equivalent of AM/PM. */
LEGAL_ALT(0);
/* AM? */
if (strcasecmp(_ctloc(am_pm[0]), bp) == 0) {
if (tm->tm_hour > 11)
return (0);
bp += strlen(_ctloc(am_pm[0]));
break;
}
/* PM? */
else if (strcasecmp(_ctloc(am_pm[1]), bp) == 0) {
if (tm->tm_hour > 11)
return (0);
tm->tm_hour += 12;
bp += strlen(_ctloc(am_pm[1]));
break;
}
/* Nothing matched. */
return (0);
case 'S': /* The seconds. */
LEGAL_ALT(ALT_O);
if (!(conv_num(&bp, &tm->tm_sec, 0, 61)))
return (0);
break;
case 'U': /* The week of year, beginning on sunday. */
case 'W': /* The week of year, beginning on monday. */
LEGAL_ALT(ALT_O);
/*
* XXX This is bogus, as we can not assume any valid
* information present in the tm structure at this
* point to calculate a real value, so just check the
* range for now.
*/
if (!(conv_num(&bp, &i, 0, 53)))
return (0);
break;
case 'w': /* The day of week, beginning on sunday. */
LEGAL_ALT(ALT_O);
if (!(conv_num(&bp, &tm->tm_wday, 0, 6)))
return (0);
break;
case 'Y': /* The year. */
LEGAL_ALT(ALT_E);
if (!(conv_num(&bp, &i, 0, 9999)))
return (0);
tm->tm_year = i - TM_YEAR_BASE;
break;
case 'y': /* The year within 100 years of the epoch. */
LEGAL_ALT(ALT_E | ALT_O);
if (!(conv_num(&bp, &i, 0, 99)))
return (0);
if (split_year) {
tm->tm_year = ((tm->tm_year / 100) * 100) + i;
break;
}
split_year = 1;
if (i <= 68)
tm->tm_year = i + 2000 - TM_YEAR_BASE;
else
tm->tm_year = i + 1900 - TM_YEAR_BASE;
break;
/*
* Miscellaneous conversions.
*/
case 'n': /* Any kind of white-space. */
case 't':
LEGAL_ALT(0);
while (isspace(*bp))
bp++;
break;
default: /* Unknown/unsupported conversion. */
return (0);
}
}
/* LINTED functional specification */
return ((char *)bp);
}
static int
conv_num(buf, dest, llim, ulim)
const unsigned char **buf;
int *dest;
int llim, ulim;
{
int result = 0;
/* The limit also determines the number of valid digits. */
int rulim = ulim;
if (**buf < '0' || **buf > '9')
return (0);
do {
result *= 10;
result += *(*buf)++ - '0';
rulim /= 10;
} while ((result * 10 <= ulim) && rulim && **buf >= '0' && **buf <= '9');
if (result < llim || result > ulim)
return (0);
*dest = result;
return (1);
}