bionic/libc/tzcode/strptime.c
2009-03-18 22:20:24 -07:00

431 lines
13 KiB
C

/* $OpenBSD: strptime.c,v 1.11 2005/08/08 08:05:38 espie Exp $ */
/* $NetBSD: strptime.c,v 1.12 1998/01/20 21:39:40 mycroft 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/localedef.h>
#include <ctype.h>
#include <locale.h>
#include <string.h>
#include <time.h>
#include "tzfile.h"
static const struct {
const char *abday[7];
const char *day[7];
const char *abmon[12];
const char *mon[12];
const char *am_pm[2];
const char *d_t_fmt;
const char *d_fmt;
const char *t_fmt;
const char *t_fmt_ampm;
} _DefaultTimeLocale = {
{
"Sun","Mon","Tue","Wed","Thu","Fri","Sat",
},
{
"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday",
"Friday", "Saturday"
},
{
"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
},
{
"January", "February", "March", "April", "May", "June", "July",
"August", "September", "October", "November", "December"
},
{
"AM", "PM"
},
"%a %b %d %H:%M:%S %Y",
"%m/%d/%y",
"%H:%M:%S",
"%I:%M:%S %p"
};
#define _ctloc(x) (_DefaultTimeLocale.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(const unsigned char **, int *, int, int);
static unsigned char *_strptime(const unsigned char *, const char *, struct tm *, int);
char *
strptime(const char *buf, const char *fmt, struct tm *tm)
{
return (char*)(_strptime((const unsigned char*)buf, fmt, tm, 1));
}
static unsigned char *
_strptime(const unsigned char *buf, const char *fmt, struct tm *tm, int initialize)
{
unsigned char c;
const unsigned char *bp;
size_t len = 0;
int alt_format, i;
static int century, relyear;
if (initialize) {
century = TM_YEAR_BASE;
relyear = -1;
}
bp = (unsigned char *)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 (NULL);
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, 0)))
return (NULL);
break;
case 'D': /* The date as "%m/%d/%y". */
_LEGAL_ALT(0);
if (!(bp = _strptime(bp, "%m/%d/%y", tm, 0)))
return (NULL);
break;
case 'R': /* The time as "%H:%M". */
_LEGAL_ALT(0);
if (!(bp = _strptime(bp, "%H:%M", tm, 0)))
return (NULL);
break;
case 'r': /* The time as "%I:%M:%S %p". */
_LEGAL_ALT(0);
if (!(bp = _strptime(bp, "%I:%M:%S %p", tm, 0)))
return (NULL);
break;
case 'T': /* The time as "%H:%M:%S". */
_LEGAL_ALT(0);
if (!(bp = _strptime(bp, "%H:%M:%S", tm, 0)))
return (NULL);
break;
case 'X': /* The time, using the locale's format. */
_LEGAL_ALT(_ALT_E);
if (!(bp = _strptime(bp, _ctloc(t_fmt), tm, 0)))
return (NULL);
break;
case 'x': /* The date, using the locale's format. */
_LEGAL_ALT(_ALT_E);
if (!(bp = _strptime(bp, _ctloc(d_fmt), tm, 0)))
return (NULL);
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]), (const char*)bp, len) == 0)
break;
/* Abbreviated name. */
len = strlen(_ctloc(abday[i]));
if (strncasecmp(_ctloc(abday[i]), (const char*)bp, len) == 0)
break;
}
/* Nothing matched. */
if (i == 7)
return (NULL);
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]), (const char*)bp, len) == 0)
break;
/* Abbreviated name. */
len = strlen(_ctloc(abmon[i]));
if (strncasecmp(_ctloc(abmon[i]), (const char*)bp, len) == 0)
break;
}
/* Nothing matched. */
if (i == 12)
return (NULL);
tm->tm_mon = i;
bp += len;
break;
case 'C': /* The century number. */
_LEGAL_ALT(_ALT_E);
if (!(_conv_num(&bp, &i, 0, 99)))
return (NULL);
century = i * 100;
break;
case 'd': /* The day of month. */
case 'e':
_LEGAL_ALT(_ALT_O);
if (!(_conv_num(&bp, &tm->tm_mday, 1, 31)))
return (NULL);
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 (NULL);
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 (NULL);
break;
case 'j': /* The day of year. */
_LEGAL_ALT(0);
if (!(_conv_num(&bp, &tm->tm_yday, 1, 366)))
return (NULL);
tm->tm_yday--;
break;
case 'M': /* The minute. */
_LEGAL_ALT(_ALT_O);
if (!(_conv_num(&bp, &tm->tm_min, 0, 59)))
return (NULL);
break;
case 'm': /* The month. */
_LEGAL_ALT(_ALT_O);
if (!(_conv_num(&bp, &tm->tm_mon, 1, 12)))
return (NULL);
tm->tm_mon--;
break;
case 'p': /* The locale's equivalent of AM/PM. */
_LEGAL_ALT(0);
/* AM? */
len = strlen(_ctloc(am_pm[0]));
if (strncasecmp(_ctloc(am_pm[0]), (const char*)bp, len) == 0) {
if (tm->tm_hour > 12) /* i.e., 13:00 AM ?! */
return (NULL);
else if (tm->tm_hour == 12)
tm->tm_hour = 0;
bp += len;
break;
}
/* PM? */
len = strlen(_ctloc(am_pm[1]));
if (strncasecmp(_ctloc(am_pm[1]), (const char*)bp, len) == 0) {
if (tm->tm_hour > 12) /* i.e., 13:00 PM ?! */
return (NULL);
else if (tm->tm_hour < 12)
tm->tm_hour += 12;
bp += len;
break;
}
/* Nothing matched. */
return (NULL);
case 'S': /* The seconds. */
_LEGAL_ALT(_ALT_O);
if (!(_conv_num(&bp, &tm->tm_sec, 0, 61)))
return (NULL);
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 (NULL);
break;
case 'w': /* The day of week, beginning on sunday. */
_LEGAL_ALT(_ALT_O);
if (!(_conv_num(&bp, &tm->tm_wday, 0, 6)))
return (NULL);
break;
case 'Y': /* The year. */
_LEGAL_ALT(_ALT_E);
if (!(_conv_num(&bp, &i, 0, 9999)))
return (NULL);
relyear = -1;
tm->tm_year = i - TM_YEAR_BASE;
break;
case 'y': /* The year within the century (2 digits). */
_LEGAL_ALT(_ALT_E | _ALT_O);
if (!(_conv_num(&bp, &relyear, 0, 99)))
return (NULL);
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 (NULL);
}
}
/*
* We need to evaluate the two digit year spec (%y)
* last as we can get a century spec (%C) at any time.
*/
if (relyear != -1) {
if (century == TM_YEAR_BASE) {
if (relyear <= 68)
tm->tm_year = relyear + 2000 - TM_YEAR_BASE;
else
tm->tm_year = relyear + 1900 - TM_YEAR_BASE;
} else {
tm->tm_year = relyear + century - TM_YEAR_BASE;
}
}
return (unsigned char*)bp;
}
static int
_conv_num(const unsigned char **buf, int *dest, int llim, int ulim)
{
int result = 0;
int rulim = ulim;
if (**buf < '0' || **buf > '9')
return (0);
/* we use rulim to break out of the loop when we run out of digits */
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);
}