glibc/time/strptime.c

744 lines
18 KiB
C

/* Convert a string representation of time to a time value.
Copyright (C) 1996, 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* XXX This version of the implementation is not really complete.
Some of the fields cannot add information alone. But if seeing
some of them in the same format (such as year, week and weekday)
this is enough information for determining the date. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <ctype.h>
#include <langinfo.h>
#include <limits.h>
#include <string.h>
#include <time.h>
#ifdef _LIBC
# include "../locale/localeinfo.h"
#endif
#ifndef __P
# if defined (__GNUC__) || (defined (__STDC__) && __STDC__)
# define __P(args) args
# else
# define __P(args) ()
# endif /* GCC. */
#endif /* Not __P. */
#if ! HAVE_LOCALTIME_R && ! defined (localtime_r)
#ifdef _LIBC
#define localtime_r __localtime_r
#else
/* Approximate localtime_r as best we can in its absence. */
#define localtime_r my_localtime_r
static struct tm *localtime_r __P ((const time_t *, struct tm *));
static struct tm *
localtime_r (t, tp)
const time_t *t;
struct tm *tp;
{
struct tm *l = localtime (t);
if (! l)
return 0;
*tp = *l;
return tp;
}
#endif /* ! _LIBC */
#endif /* ! HAVE_LOCALTIME_R && ! defined (localtime_r) */
#define match_char(ch1, ch2) if (ch1 != ch2) return NULL
#if defined __GNUC__ && __GNUC__ >= 2
# define match_string(cs1, s2) \
({ size_t len = strlen (cs1); \
int result = strncasecmp ((cs1), (s2), len) == 0; \
if (result) (s2) += len; \
result; })
#else
/* Oh come on. Get a reasonable compiler. */
# define match_string(cs1, s2) \
(strncasecmp ((cs1), (s2), strlen (cs1)) ? 0 : ((s2) += strlen (cs1), 1))
#endif
/* We intentionally do not use isdigit() for testing because this will
lead to problems with the wide character version. */
#define get_number(from, to) \
do { \
val = 0; \
if (*rp < '0' || *rp > '9') \
return NULL; \
do { \
val *= 10; \
val += *rp++ - '0'; \
} while (val * 10 <= to && *rp >= '0' && *rp <= '9'); \
if (val < from || val > to) \
return NULL; \
} while (0)
#ifdef _NL_CURRENT
# define get_alt_number(from, to) \
do { \
if (*decided != raw) \
{ \
const char *alts = _NL_CURRENT (LC_TIME, ALT_DIGITS); \
val = 0; \
while (*alts != '\0') \
{ \
size_t len = strlen (alts); \
if (strncasecmp (alts, rp, len) == 0) \
break; \
alts = strchr (alts, '\0') + 1; \
++val; \
} \
if (*alts == '\0') \
{ \
if (*decided == loc && val != 0) \
return NULL; \
} \
else \
{ \
*decided = loc; \
break; \
} \
} \
get_number (from, to); \
} while (0)
#else
# define get_alt_number(from, to) \
/* We don't have the alternate representation. */ \
get_number(from, to)
#endif
#define recursive(new_fmt) \
(*(new_fmt) != '\0' \
&& (rp = strptime_internal (rp, (new_fmt), tm, decided)) != NULL)
#ifdef _LIBC
/* This is defined in locale/C-time.c in the GNU libc. */
extern const struct locale_data _nl_C_LC_TIME;
# define weekday_name (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (DAY_1)].string)
# define ab_weekday_name \
(&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (ABDAY_1)].string)
# define month_name (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (MON_1)].string)
# define ab_month_name (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (ABMON_1)].string)
# define HERE_D_T_FMT (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (D_T_FMT)].string)
# define HERE_D_FMT (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (D_T_FMT)].string)
# define HERE_AM_STR (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (AM_STR)].string)
# define HERE_PM_STR (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (PM_STR)].string)
# define HERE_T_FMT_AMPM \
(_nl_C_LC_TIME.values[_NL_ITEM_INDEX (T_FMT_AMPM)].string)
# define HERE_T_FMT (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (T_FMT)].string)
#else
static char const weekday_name[][10] =
{
"Sunday", "Monday", "Tuesday", "Wednesday",
"Thursday", "Friday", "Saturday"
};
static char const ab_weekday_name[][4] =
{
"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
};
static char const month_name[][10] =
{
"January", "February", "March", "April", "May", "June",
"July", "August", "September", "October", "November", "December"
};
static char const ab_month_name[][4] =
{
"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};
# define HERE_D_T_FMT "%a %b %e %H:%M:%S %Y"
# define HERE_D_FMT "%m/%d/%y"
# define HERE_AM_STR "AM"
# define HERE_PM_STR "PM"
# define HERE_T_FMT_AMPM "%I:%M:%S %p"
# define HERE_T_FMT "%H:%M:%S"
#endif
/* Status of lookup: do we use the locale data or the raw data? */
enum locale_status { not, loc, raw };
static char *
#ifdef _LIBC
internal_function
#endif
strptime_internal __P ((const char *buf, const char *format, struct tm *tm,
enum locale_status *decided));
static char *
#ifdef _LIBC
internal_function
#endif
strptime_internal (buf, format, tm, decided)
const char *buf;
const char *format;
struct tm *tm;
enum locale_status *decided;
{
const char *rp;
const char *fmt;
int cnt;
size_t val;
int have_I, is_pm;
rp = buf;
fmt = format;
have_I = is_pm = 0;
while (*fmt != '\0')
{
/* A white space in the format string matches 0 more or white
space in the input string. */
if (isspace (*fmt))
{
while (isspace (*rp))
++rp;
++fmt;
continue;
}
/* Any character but `%' must be matched by the same character
in the iput string. */
if (*fmt != '%')
{
match_char (*fmt++, *rp++);
continue;
}
++fmt;
#ifndef _NL_CURRENT
/* We need this for handling the `E' modifier. */
start_over:
#endif
switch (*fmt++)
{
case '%':
/* Match the `%' character itself. */
match_char ('%', *rp++);
break;
case 'a':
case 'A':
/* Match day of week. */
for (cnt = 0; cnt < 7; ++cnt)
{
#ifdef _NL_CURRENT
if (*decided !=raw)
{
if (match_string (_NL_CURRENT (LC_TIME, DAY_1 + cnt), rp))
{
if (*decided == not
&& strcmp (_NL_CURRENT (LC_TIME, DAY_1 + cnt),
weekday_name[cnt]))
*decided = loc;
break;
}
if (match_string (_NL_CURRENT (LC_TIME, ABDAY_1 + cnt), rp))
{
if (*decided == not
&& strcmp (_NL_CURRENT (LC_TIME, ABDAY_1 + cnt),
ab_weekday_name[cnt]))
*decided = loc;
break;
}
}
#endif
if (*decided != loc
&& (match_string (weekday_name[cnt], rp)
|| match_string (ab_weekday_name[cnt], rp)))
{
*decided = raw;
break;
}
}
if (cnt == 7)
/* Does not match a weekday name. */
return NULL;
tm->tm_wday = cnt;
break;
case 'b':
case 'B':
case 'h':
/* Match month name. */
for (cnt = 0; cnt < 12; ++cnt)
{
#ifdef _NL_CURRENT
if (*decided !=raw)
{
if (match_string (_NL_CURRENT (LC_TIME, MON_1 + cnt), rp))
{
if (*decided == not
&& strcmp (_NL_CURRENT (LC_TIME, MON_1 + cnt),
month_name[cnt]))
*decided = loc;
break;
}
if (match_string (_NL_CURRENT (LC_TIME, ABMON_1 + cnt), rp))
{
if (*decided == not
&& strcmp (_NL_CURRENT (LC_TIME, ABMON_1 + cnt),
ab_month_name[cnt]))
*decided = loc;
break;
}
}
#endif
if (match_string (month_name[cnt], rp)
|| match_string (ab_month_name[cnt], rp))
{
*decided = raw;
break;
}
}
if (cnt == 12)
/* Does not match a month name. */
return NULL;
tm->tm_mon = cnt;
break;
case 'c':
/* Match locale's date and time format. */
#ifdef _NL_CURRENT
if (*decided != raw)
{
if (!recursive (_NL_CURRENT (LC_TIME, D_T_FMT)))
{
if (*decided == loc)
return NULL;
}
else
{
if (*decided == not &&
strcmp (_NL_CURRENT (LC_TIME, D_T_FMT), HERE_D_T_FMT))
*decided = loc;
break;
}
*decided = raw;
}
#endif
if (!recursive (HERE_D_T_FMT))
return NULL;
break;
case 'C':
/* Match century number. */
get_number (0, 99);
/* We don't need the number. */
break;
case 'd':
case 'e':
/* Match day of month. */
get_number (1, 31);
tm->tm_mday = val;
break;
case 'x':
#ifdef _NL_CURRENT
if (*decided != raw)
{
if (!recursive (_NL_CURRENT (LC_TIME, D_FMT)))
{
if (*decided == loc)
return NULL;
}
else
{
if (decided == not
&& strcmp (_NL_CURRENT (LC_TIME, D_FMT), HERE_D_FMT))
*decided = loc;
break;
}
*decided = raw;
}
#endif
/* Fall through. */
case 'D':
/* Match standard day format. */
if (!recursive (HERE_D_FMT))
return NULL;
break;
case 'H':
/* Match hour in 24-hour clock. */
get_number (0, 23);
tm->tm_hour = val;
have_I = 0;
break;
case 'I':
/* Match hour in 12-hour clock. */
get_number (1, 12);
tm->tm_hour = val % 12;
have_I = 1;
break;
case 'j':
/* Match day number of year. */
get_number (1, 366);
tm->tm_yday = val - 1;
break;
case 'm':
/* Match number of month. */
get_number (1, 12);
tm->tm_mon = val - 1;
break;
case 'M':
/* Match minute. */
get_number (0, 59);
tm->tm_min = val;
break;
case 'n':
case 't':
/* Match any white space. */
while (isspace (*rp))
++rp;
break;
case 'p':
/* Match locale's equivalent of AM/PM. */
#ifdef _NL_CURRENT
if (*decided != raw)
{
if (match_string (_NL_CURRENT (LC_TIME, AM_STR), rp))
{
if (strcmp (_NL_CURRENT (LC_TIME, AM_STR), HERE_AM_STR))
*decided = loc;
break;
}
if (match_string (_NL_CURRENT (LC_TIME, PM_STR), rp))
{
if (strcmp (_NL_CURRENT (LC_TIME, PM_STR), HERE_PM_STR))
*decided = loc;
is_pm = 1;
break;
}
*decided = raw;
}
#endif
if (!match_string (HERE_AM_STR, rp))
if (match_string (HERE_PM_STR, rp))
is_pm = 1;
else
return NULL;
break;
case 'r':
#ifdef _NL_CURRENT
if (*decided != raw)
{
if (!recursive (_NL_CURRENT (LC_TIME, T_FMT_AMPM)))
{
if (*decided == loc)
return NULL;
}
else
{
if (*decided == not &&
strcmp (_NL_CURRENT (LC_TIME, T_FMT_AMPM),
HERE_T_FMT_AMPM))
*decided = loc;
break;
}
*decided = raw;
}
#endif
if (!recursive (HERE_T_FMT_AMPM))
return NULL;
break;
case 'R':
if (!recursive ("%H:%M"))
return NULL;
break;
case 's':
{
/* The number of seconds may be very high so we cannot use
the `get_number' macro. Instead read the number
character for character and construct the result while
doing this. */
time_t secs;
if (*rp < '0' || *rp > '9')
/* We need at least one digit. */
return NULL;
do
{
secs *= 10;
secs += *rp++ - '0';
}
while (*rp >= '0' && *rp <= '9');
if (localtime_r (&secs, tm) == NULL)
/* Error in function. */
return NULL;
}
break;
case 'S':
get_number (0, 61);
tm->tm_sec = val;
break;
case 'X':
#ifdef _NL_CURRENT
if (*decided != raw)
{
if (!recursive (_NL_CURRENT (LC_TIME, T_FMT)))
{
if (*decided == loc)
return NULL;
}
else
{
if (strcmp (_NL_CURRENT (LC_TIME, T_FMT), HERE_T_FMT))
*decided = loc;
break;
}
*decided = raw;
}
#endif
/* Fall through. */
case 'T':
if (!recursive (HERE_T_FMT))
return NULL;
break;
case 'u':
get_number (1, 7);
tm->tm_wday = val % 7;
break;
case 'g':
get_number (0, 99);
/* XXX This cannot determine any field in TM. */
break;
case 'G':
if (*rp < '0' || *rp > '9')
return NULL;
/* XXX Ignore the number since we would need some more
information to compute a real date. */
do
++rp;
while (*rp >= '0' && *rp <= '9');
break;
case 'U':
case 'V':
case 'W':
get_number (0, 53);
/* XXX This cannot determine any field in TM without some
information. */
break;
case 'w':
/* Match number of weekday. */
get_number (0, 6);
tm->tm_wday = val;
break;
case 'y':
/* Match year within century. */
get_number (0, 99);
/* The "Year 2000 :The Millennium Rollover" paper suggests that
values in the range 69-99 refer to the twentieth century. */
tm->tm_year = val >= 69 ? val : val + 100;
break;
case 'Y':
/* Match year including century number. */
get_number (0, 9999);
tm->tm_year = val - 1900;
break;
case 'Z':
/* XXX How to handle this? */
break;
case 'E':
#ifdef _NL_CURRENT
switch (*fmt++)
{
case 'c':
/* Match locale's alternate date and time format. */
if (*decided != raw)
{
const char *fmt = _NL_CURRENT (LC_TIME, ERA_D_T_FMT);
if (*fmt == '\0')
fmt = _NL_CURRENT (LC_TIME, D_T_FMT);
if (!recursive (fmt))
{
if (*decided == loc)
return NULL;
}
else
{
if (strcmp (fmt, HERE_D_T_FMT))
*decided = loc;
break;
}
*decided = raw;
}
/* The C locale has no era information, so use the
normal representation. */
if (!recursive (HERE_D_T_FMT))
return NULL;
break;
case 'C':
case 'y':
case 'Y':
/* Match name of base year in locale's alternate
representation. */
/* XXX This is currently not implemented. It should
use the value _NL_CURRENT (LC_TIME, ERA). */
break;
case 'x':
if (*decided != raw)
{
const char *fmt = _NL_CURRENT (LC_TIME, ERA_D_FMT);
if (*fmt == '\0')
fmt = _NL_CURRENT (LC_TIME, D_FMT);
if (!recursive (fmt))
{
if (*decided == loc)
return NULL;
}
else
{
if (strcmp (fmt, HERE_D_FMT))
*decided = loc;
break;
}
*decided = raw;
}
if (!recursive (HERE_D_FMT))
return NULL;
break;
case 'X':
if (*decided != raw)
{
const char *fmt = _NL_CURRENT (LC_TIME, ERA_T_FMT);
if (*fmt == '\0')
fmt = _NL_CURRENT (LC_TIME, T_FMT);
if (!recursive (fmt))
{
if (*decided == loc)
return NULL;
}
else
{
if (strcmp (fmt, HERE_T_FMT))
*decided = loc;
break;
}
*decided = raw;
}
if (!recursive (HERE_T_FMT))
return NULL;
break;
default:
return NULL;
}
break;
#else
/* We have no information about the era format. Just use
the normal format. */
if (*fmt != 'c' && *fmt != 'C' && *fmt != 'y' && *fmt != 'Y'
&& *fmt != 'x' && *fmt != 'X')
/* This is an illegal format. */
return NULL;
goto start_over;
#endif
case 'O':
switch (*fmt++)
{
case 'd':
case 'e':
/* Match day of month using alternate numeric symbols. */
get_alt_number (1, 31);
tm->tm_mday = val;
break;
case 'H':
/* Match hour in 24-hour clock using alternate numeric
symbols. */
get_alt_number (0, 23);
tm->tm_hour = val;
have_I = 0;
break;
case 'I':
/* Match hour in 12-hour clock using alternate numeric
symbols. */
get_alt_number (1, 12);
tm->tm_hour = val - 1;
have_I = 1;
break;
case 'm':
/* Match month using alternate numeric symbols. */
get_alt_number (1, 12);
tm->tm_mon = val - 1;
break;
case 'M':
/* Match minutes using alternate numeric symbols. */
get_alt_number (0, 59);
tm->tm_min = val;
break;
case 'S':
/* Match seconds using alternate numeric symbols. */
get_alt_number (0, 61);
tm->tm_sec = val;
break;
case 'U':
case 'V':
case 'W':
get_alt_number (0, 53);
/* XXX This cannot determine any field in TM without
further information. */
break;
case 'w':
/* Match number of weekday using alternate numeric symbols. */
get_alt_number (0, 6);
tm->tm_wday = val;
break;
case 'y':
/* Match year within century using alternate numeric symbols. */
get_alt_number (0, 99);
tm->tm_year = val >= 69 ? val : val + 100;
break;
default:
return NULL;
}
break;
default:
return NULL;
}
}
if (have_I && is_pm)
tm->tm_hour += 12;
return (char *) rp;
}
char *
strptime (buf, format, tm)
const char *buf;
const char *format;
struct tm *tm;
{
enum locale_status decided;
#ifdef _NL_CURRENT
decided = not;
#else
decided = raw;
#endif
return strptime_internal (buf, format, tm, &decided);
}