minix/lib/libc/stdtime/strptime.c
2010-06-22 21:42:49 +00:00

454 lines
12 KiB
C

/*
* Copyright (c) 1999 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* 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. Neither the name of KTH 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 KTH AND ITS 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 KTH OR ITS 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. */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <ctype.h>
#ifdef __minix
#include <time.h>
#include <string.h>
#include <stdlib.h>
#endif
#ifndef __minix
#include "roken.h"
__RCSID("$Heimdal: strptime.c,v 1.2 1999/11/12 15:29:55 assar Exp $"
"$NetBSD: strptime.c,v 1.1.1.3 2002/09/12 12:41:42 joda Exp $");
#endif
static const char *abb_weekdays[] = {
"Sun",
"Mon",
"Tue",
"Wed",
"Thu",
"Fri",
"Sat",
NULL
};
static const char *full_weekdays[] = {
"Sunday",
"Monday",
"Tuesday",
"Wednesday",
"Thursday",
"Friday",
"Saturday",
NULL
};
static const char *abb_month[] = {
"Jan",
"Feb",
"Mar",
"Apr",
"May",
"Jun",
"Jul",
"Aug",
"Sep",
"Oct",
"Nov",
"Dec",
NULL
};
static const char *full_month[] = {
"January",
"February",
"Mars",
"April",
"May",
"June",
"July",
"August",
"September",
"October",
"November",
"December",
NULL,
};
static const char *ampm[] = {
"am",
"pm",
NULL
};
/*
* Try to match `*buf' to one of the strings in `strs'. Return the
* index of the matching string (or -1 if none). Also advance buf.
*/
static int
match_string (const char **buf, const char **strs)
{
int i = 0;
for (i = 0; strs[i] != NULL; ++i) {
int len = strlen (strs[i]);
if (strncasecmp (*buf, strs[i], len) == 0) {
*buf += len;
return i;
}
}
return -1;
}
/*
* tm_year is relative this year */
const int tm_year_base = 1900;
/*
* Return TRUE iff `year' was a leap year.
*/
static int
is_leap_year (int year)
{
return (year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0);
}
/*
* Return the weekday [0,6] (0 = Sunday) of the first day of `year'
*/
static int
first_day (int year)
{
int ret = 4;
for (; year > 1970; --year)
ret = (ret + 365 + is_leap_year (year) ? 1 : 0) % 7;
return ret;
}
/*
* Set `timeptr' given `wnum' (week number [0, 53])
*/
static void
set_week_number_sun (struct tm *timeptr, int wnum)
{
int fday = first_day (timeptr->tm_year + tm_year_base);
timeptr->tm_yday = wnum * 7 + timeptr->tm_wday - fday;
if (timeptr->tm_yday < 0) {
timeptr->tm_wday = fday;
timeptr->tm_yday = 0;
}
}
/*
* Set `timeptr' given `wnum' (week number [0, 53])
*/
static void
set_week_number_mon (struct tm *timeptr, int wnum)
{
int fday = (first_day (timeptr->tm_year + tm_year_base) + 6) % 7;
timeptr->tm_yday = wnum * 7 + (timeptr->tm_wday + 6) % 7 - fday;
if (timeptr->tm_yday < 0) {
timeptr->tm_wday = (fday + 1) % 7;
timeptr->tm_yday = 0;
}
}
/*
* Set `timeptr' given `wnum' (week number [0, 53])
*/
static void
set_week_number_mon4 (struct tm *timeptr, int wnum)
{
int fday = (first_day (timeptr->tm_year + tm_year_base) + 6) % 7;
int offset = 0;
if (fday < 4)
offset += 7;
timeptr->tm_yday = offset + (wnum - 1) * 7 + timeptr->tm_wday - fday;
if (timeptr->tm_yday < 0) {
timeptr->tm_wday = fday;
timeptr->tm_yday = 0;
}
}
/*
*
*/
char *
strptime (const char *buf, const char *format, struct tm *timeptr)
{
char c;
for (; (c = *format) != '\0'; ++format) {
char *s;
int ret;
if (isspace (c)) {
while (isspace (*buf))
++buf;
} else if (c == '%' && format[1] != '\0') {
c = *++format;
if (c == 'E' || c == 'O')
c = *++format;
switch (c) {
case 'A' :
ret = match_string (&buf, full_weekdays);
if (ret < 0)
return NULL;
timeptr->tm_wday = ret;
break;
case 'a' :
ret = match_string (&buf, abb_weekdays);
if (ret < 0)
return NULL;
timeptr->tm_wday = ret;
break;
case 'B' :
ret = match_string (&buf, full_month);
if (ret < 0)
return NULL;
timeptr->tm_mon = ret;
break;
case 'b' :
case 'h' :
ret = match_string (&buf, abb_month);
if (ret < 0)
return NULL;
timeptr->tm_mon = ret;
break;
case 'C' :
ret = strtol (buf, &s, 10);
if (s == buf)
return NULL;
timeptr->tm_year = (ret * 100) - tm_year_base;
buf = s;
break;
case 'c' :
abort ();
case 'D' : /* %m/%d/%y */
s = strptime (buf, "%m/%d/%y", timeptr);
if (s == NULL)
return NULL;
buf = s;
break;
case 'd' :
case 'e' :
ret = strtol (buf, &s, 10);
if (s == buf)
return NULL;
timeptr->tm_mday = ret;
buf = s;
break;
case 'H' :
case 'k' :
ret = strtol (buf, &s, 10);
if (s == buf)
return NULL;
timeptr->tm_hour = ret;
buf = s;
break;
case 'I' :
case 'l' :
ret = strtol (buf, &s, 10);
if (s == buf)
return NULL;
if (ret == 12)
timeptr->tm_hour = 0;
else
timeptr->tm_hour = ret;
buf = s;
break;
case 'j' :
ret = strtol (buf, &s, 10);
if (s == buf)
return NULL;
timeptr->tm_yday = ret - 1;
buf = s;
break;
case 'm' :
ret = strtol (buf, &s, 10);
if (s == buf)
return NULL;
timeptr->tm_mon = ret - 1;
buf = s;
break;
case 'M' :
ret = strtol (buf, &s, 10);
if (s == buf)
return NULL;
timeptr->tm_min = ret;
buf = s;
break;
case 'n' :
if (*buf == '\n')
++buf;
else
return NULL;
break;
case 'p' :
ret = match_string (&buf, ampm);
if (ret < 0)
return NULL;
if (timeptr->tm_hour == 0) {
if (ret == 1)
timeptr->tm_hour = 12;
} else
timeptr->tm_hour += 12;
break;
case 'r' : /* %I:%M:%S %p */
s = strptime (buf, "%I:%M:%S %p", timeptr);
if (s == NULL)
return NULL;
buf = s;
break;
case 'R' : /* %H:%M */
s = strptime (buf, "%H:%M", timeptr);
if (s == NULL)
return NULL;
buf = s;
break;
case 'S' :
ret = strtol (buf, &s, 10);
if (s == buf)
return NULL;
timeptr->tm_sec = ret;
buf = s;
break;
case 't' :
if (*buf == '\t')
++buf;
else
return NULL;
break;
case 'T' : /* %H:%M:%S */
case 'X' :
s = strptime (buf, "%H:%M:%S", timeptr);
if (s == NULL)
return NULL;
buf = s;
break;
case 'u' :
ret = strtol (buf, &s, 10);
if (s == buf)
return NULL;
timeptr->tm_wday = ret - 1;
buf = s;
break;
case 'w' :
ret = strtol (buf, &s, 10);
if (s == buf)
return NULL;
timeptr->tm_wday = ret;
buf = s;
break;
case 'U' :
ret = strtol (buf, &s, 10);
if (s == buf)
return NULL;
set_week_number_sun (timeptr, ret);
buf = s;
break;
case 'V' :
ret = strtol (buf, &s, 10);
if (s == buf)
return NULL;
set_week_number_mon4 (timeptr, ret);
buf = s;
break;
case 'W' :
ret = strtol (buf, &s, 10);
if (s == buf)
return NULL;
set_week_number_mon (timeptr, ret);
buf = s;
break;
case 'x' :
s = strptime (buf, "%Y:%m:%d", timeptr);
if (s == NULL)
return NULL;
buf = s;
break;
case 'y' :
ret = strtol (buf, &s, 10);
if (s == buf)
return NULL;
if (ret < 70)
timeptr->tm_year = 100 + ret;
else
timeptr->tm_year = ret;
buf = s;
break;
case 'Y' :
ret = strtol (buf, &s, 10);
if (s == buf)
return NULL;
timeptr->tm_year = ret - tm_year_base;
buf = s;
break;
case 'Z' :
abort ();
case '\0' :
--format;
/* FALLTHROUGH */
case '%' :
if (*buf == '%')
++buf;
else
return NULL;
break;
default :
if (*buf == '%' || *++buf == c)
++buf;
else
return NULL;
break;
}
} else {
if (*buf == c)
++buf;
else
return NULL;
}
}
return (char *)buf;
}