505 lines
13 KiB
C
505 lines
13 KiB
C
/* Copyright (C) 1991, 92, 93, 94, 95, 96 Free Software Foundation, Inc.
|
||
This file is part of the GNU C Library.
|
||
|
||
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., 675 Mass Ave,
|
||
Cambridge, MA 02139, USA. */
|
||
|
||
#include <ansidecl.h>
|
||
#include <ctype.h>
|
||
#include <stddef.h>
|
||
#include <stdio.h>
|
||
#include <stdlib.h>
|
||
#include <string.h>
|
||
#include <time.h>
|
||
|
||
/* Defined in mktime.c. */
|
||
extern CONST unsigned short int __mon_yday[2][13];
|
||
|
||
#define NOID
|
||
#include "tzfile.h"
|
||
|
||
extern int __use_tzfile;
|
||
extern void EXFUN(__tzfile_read, (CONST char *file));
|
||
extern void EXFUN(__tzfile_default, (char *std AND char *dst AND
|
||
long int stdoff AND long int dstoff));
|
||
extern int EXFUN(__tzfile_compute, (time_t, struct tm));
|
||
|
||
char *__tzname[2] = { (char *) "GMT", (char *) "GMT" };
|
||
int __daylight = 0;
|
||
long int __timezone = 0L;
|
||
|
||
weak_alias (__tzname, tzname)
|
||
weak_alias (__daylight, daylight)
|
||
weak_alias (__timezone, timezone)
|
||
|
||
|
||
#define min(a, b) ((a) < (b) ? (a) : (b))
|
||
#define max(a, b) ((a) > (b) ? (a) : (b))
|
||
#define sign(x) ((x) < 0 ? -1 : 1)
|
||
|
||
|
||
/* This structure contains all the information about a
|
||
timezone given in the POSIX standard TZ envariable. */
|
||
typedef struct
|
||
{
|
||
char *name;
|
||
|
||
/* When to change. */
|
||
enum { J0, J1, M } type; /* Interpretation of: */
|
||
unsigned short int m, n, d; /* Month, week, day. */
|
||
unsigned int secs; /* Time of day. */
|
||
|
||
long int offset; /* Seconds east of GMT (west if < 0). */
|
||
|
||
/* We cache the computed time of change for a
|
||
given year so we don't have to recompute it. */
|
||
time_t change; /* When to change to this zone. */
|
||
int computed_for; /* Year above is computed for. */
|
||
} tz_rule;
|
||
|
||
/* tz_rules[0] is standard, tz_rules[1] is daylight. */
|
||
static tz_rule tz_rules[2];
|
||
|
||
int __tzset_run = 0;
|
||
|
||
/* Interpret the TZ envariable. */
|
||
void
|
||
DEFUN_VOID(__tzset)
|
||
{
|
||
register CONST char *tz;
|
||
register size_t l;
|
||
unsigned short int hh, mm, ss;
|
||
unsigned short int whichrule;
|
||
|
||
/* Free old storage. */
|
||
if (tz_rules[0].name != NULL && *tz_rules[0].name != '\0')
|
||
{
|
||
free((PTR) tz_rules[0].name);
|
||
tz_rules[0].name = NULL;
|
||
}
|
||
if (tz_rules[1].name != NULL && *tz_rules[1].name != '\0' &&
|
||
tz_rules[1].name != tz_rules[0].name)
|
||
{
|
||
free((PTR) tz_rules[1].name);
|
||
tz_rules[1].name = NULL;
|
||
}
|
||
|
||
/* Examine the TZ environment variable. */
|
||
tz = getenv ("TZ");
|
||
|
||
/* A leading colon means "implementation defined syntax".
|
||
We ignore the colon and always use the same algorithm:
|
||
try a data file, and if none exists parse the 1003.1 syntax. */
|
||
if (tz && *tz == ':')
|
||
++tz;
|
||
|
||
/* Try to read a data file. */
|
||
__tzfile_read (tz);
|
||
if (__use_tzfile)
|
||
{
|
||
__tzset_run = 1;
|
||
return;
|
||
}
|
||
|
||
/* No data file found. Default to UTC if nothing specified. */
|
||
|
||
if (tz == NULL || *tz == '\0')
|
||
{
|
||
static const char UTC[] = "UTC";
|
||
size_t len = sizeof UTC;
|
||
tz_rules[0].name = (char *) malloc(len);
|
||
if (tz_rules[0].name == NULL)
|
||
return;
|
||
tz_rules[1].name = (char *) malloc(len);
|
||
if (tz_rules[1].name == NULL)
|
||
return;
|
||
memcpy ((PTR) tz_rules[0].name, UTC, len);
|
||
memcpy ((PTR) tz_rules[1].name, UTC, len);
|
||
tz_rules[0].type = tz_rules[1].type = J0;
|
||
tz_rules[0].m = tz_rules[0].n = tz_rules[0].d = 0;
|
||
tz_rules[1].m = tz_rules[1].n = tz_rules[1].d = 0;
|
||
tz_rules[0].secs = tz_rules[1].secs = 0;
|
||
tz_rules[0].offset = tz_rules[1].offset = 0L;
|
||
tz_rules[0].change = tz_rules[1].change = (time_t) -1;
|
||
tz_rules[0].computed_for = tz_rules[1].computed_for = 0;
|
||
__tzset_run = 1;
|
||
return;
|
||
}
|
||
|
||
/* Clear out old state and reset to unnamed UTC. */
|
||
memset (tz_rules, 0, sizeof tz_rules);
|
||
tz_rules[0].name = tz_rules[1].name = (char *) "";
|
||
|
||
/* Get the standard timezone name. */
|
||
tz_rules[0].name = (char *) malloc (strlen (tz) + 1);
|
||
if (tz_rules[0].name == NULL)
|
||
/* Don't set __tzset_run so we will try again. */
|
||
return;
|
||
|
||
if (sscanf(tz, "%[^0-9,+-]", tz_rules[0].name) != 1 ||
|
||
(l = strlen(tz_rules[0].name)) < 3)
|
||
{
|
||
free (tz_rules[0].name);
|
||
tz_rules[0].name = (char *) "";
|
||
return;
|
||
}
|
||
|
||
{
|
||
char *n = realloc ((PTR) tz_rules[0].name, l + 1);
|
||
if (n != NULL)
|
||
tz_rules[0].name = n;
|
||
}
|
||
|
||
tz += l;
|
||
|
||
/* Figure out the standard offset from UTC. */
|
||
if (*tz == '\0' || (*tz != '+' && *tz != '-' && !isdigit(*tz)))
|
||
return;
|
||
|
||
if (*tz == '-' || *tz == '+')
|
||
tz_rules[0].offset = *tz++ == '-' ? 1L : -1L;
|
||
else
|
||
tz_rules[0].offset = -1L;
|
||
switch (sscanf (tz, "%hu:%hu:%hu", &hh, &mm, &ss))
|
||
{
|
||
default:
|
||
return;
|
||
case 1:
|
||
mm = 0;
|
||
case 2:
|
||
ss = 0;
|
||
case 3:
|
||
break;
|
||
}
|
||
tz_rules[0].offset *= (min(ss, 59) + (min(mm, 59) * 60) +
|
||
(min(hh, 23) * 60 * 60));
|
||
|
||
for (l = 0; l < 3; ++l)
|
||
{
|
||
while (isdigit(*tz))
|
||
++tz;
|
||
if (l < 2 && *tz == ':')
|
||
++tz;
|
||
}
|
||
|
||
/* Get the DST timezone name (if any). */
|
||
if (*tz != '\0')
|
||
{
|
||
char *n = malloc (strlen(tz) + 1);
|
||
if (n != NULL)
|
||
{
|
||
tz_rules[1].name = n;
|
||
if (sscanf(tz, "%[^0-9,+-]", tz_rules[1].name) != 1 ||
|
||
(l = strlen(tz_rules[1].name)) < 3)
|
||
{
|
||
free (n);
|
||
tz_rules[1].name = (char *) "";
|
||
goto done_names; /* Punt on name, set up the offsets. */
|
||
}
|
||
n = realloc ((PTR) tz_rules[1].name, l + 1);
|
||
if (n != NULL)
|
||
tz_rules[1].name = n;
|
||
}
|
||
}
|
||
|
||
tz += l;
|
||
|
||
/* Figure out the DST offset from GMT. */
|
||
if (*tz == '-' || *tz == '+')
|
||
tz_rules[1].offset = *tz++ == '-' ? 1L : -1L;
|
||
else
|
||
tz_rules[1].offset = -1L;
|
||
|
||
switch (sscanf (tz, "%hu:%hu:%hu", &hh, &mm, &ss))
|
||
{
|
||
default:
|
||
/* Default to one hour later than standard time. */
|
||
tz_rules[1].offset = tz_rules[0].offset + (60 * 60);
|
||
break;
|
||
|
||
case 1:
|
||
mm = 0;
|
||
case 2:
|
||
ss = 0;
|
||
case 3:
|
||
tz_rules[1].offset *= (min(ss, 59) + (min(mm, 59) * 60) +
|
||
(min(hh, 23) * (60 * 60)));
|
||
break;
|
||
}
|
||
for (l = 0; l < 3; ++l)
|
||
{
|
||
while (isdigit (*tz))
|
||
++tz;
|
||
if (l < 2 && *tz == ':')
|
||
++tz;
|
||
}
|
||
|
||
done_names:
|
||
|
||
if (*tz == '\0' || (tz[0] == ',' && tz[1] == '\0'))
|
||
{
|
||
/* There is no rule. See if there is a default rule file. */
|
||
__tzfile_default (tz_rules[0].name, tz_rules[1].name,
|
||
tz_rules[0].offset, tz_rules[1].offset);
|
||
if (__use_tzfile)
|
||
{
|
||
__tzset_run = 1;
|
||
return;
|
||
}
|
||
}
|
||
|
||
/* Figure out the standard <-> DST rules. */
|
||
for (whichrule = 0; whichrule < 2; ++whichrule)
|
||
{
|
||
register tz_rule *tzr = &tz_rules[whichrule];
|
||
|
||
if (*tz == ',')
|
||
{
|
||
++tz;
|
||
if (*tz == '\0')
|
||
return;
|
||
}
|
||
|
||
/* Get the date of the change. */
|
||
if (*tz == 'J' || isdigit (*tz))
|
||
{
|
||
char *end;
|
||
tzr->type = *tz == 'J' ? J1 : J0;
|
||
if (tzr->type == J1 && !isdigit (*++tz))
|
||
return;
|
||
tzr->d = (unsigned short int) strtoul (tz, &end, 10);
|
||
if (end == tz || tzr->d > 365)
|
||
return;
|
||
else if (tzr->type == J1 && tzr->d == 0)
|
||
return;
|
||
tz = end;
|
||
}
|
||
else if (*tz == 'M')
|
||
{
|
||
int n;
|
||
tzr->type = M;
|
||
if (sscanf (tz, "M%hu.%hu.%hu%n",
|
||
&tzr->m, &tzr->n, &tzr->d, &n) != 3 ||
|
||
tzr->m < 1 || tzr->m > 12 ||
|
||
tzr->n < 1 || tzr->n > 5 || tzr->d > 6)
|
||
return;
|
||
tz += n;
|
||
}
|
||
else if (*tz == '\0')
|
||
{
|
||
/* United States Federal Law, the equivalent of "M4.1.0,M10.5.0". */
|
||
tzr->type = M;
|
||
if (tzr == &tz_rules[0])
|
||
{
|
||
tzr->m = 4;
|
||
tzr->n = 1;
|
||
tzr->d = 0;
|
||
}
|
||
else
|
||
{
|
||
tzr->m = 10;
|
||
tzr->n = 5;
|
||
tzr->d = 0;
|
||
}
|
||
}
|
||
else
|
||
return;
|
||
|
||
if (*tz != '\0' && *tz != '/' && *tz != ',')
|
||
return;
|
||
else if (*tz == '/')
|
||
{
|
||
/* Get the time of day of the change. */
|
||
++tz;
|
||
if (*tz == '\0')
|
||
return;
|
||
switch (sscanf (tz, "%hu:%hu:%hu", &hh, &mm, &ss))
|
||
{
|
||
default:
|
||
hh = 2; /* Default to 2:00 AM. */
|
||
case 1:
|
||
mm = 0;
|
||
case 2:
|
||
ss = 0;
|
||
case 3:
|
||
break;
|
||
}
|
||
for (l = 0; l < 3; ++l)
|
||
{
|
||
while (isdigit(*tz))
|
||
++tz;
|
||
if (l < 2 && *tz == ':')
|
||
++tz;
|
||
}
|
||
tzr->secs = (hh * 60 * 60) + (mm * 60) + ss;
|
||
}
|
||
else
|
||
/* Default to 2:00 AM. */
|
||
tzr->secs = 2 * 60 * 60;
|
||
|
||
tzr->computed_for = -1;
|
||
}
|
||
|
||
__tzset_run = 1;
|
||
}
|
||
|
||
/* Maximum length of a timezone name. __tz_compute keeps this up to date
|
||
(never decreasing it) when ! __use_tzfile.
|
||
tzfile.c keeps it up to date when __use_tzfile. */
|
||
size_t __tzname_cur_max;
|
||
|
||
long int
|
||
DEFUN_VOID(__tzname_max)
|
||
{
|
||
if (! __tzset_run)
|
||
__tzset ();
|
||
|
||
return __tzname_cur_max;
|
||
}
|
||
|
||
/* Figure out the exact time (as a time_t) in YEAR
|
||
when the change described by RULE will occur and
|
||
put it in RULE->change, saving YEAR in RULE->computed_for.
|
||
Return nonzero if successful, zero on failure. */
|
||
static int
|
||
DEFUN(compute_change, (rule, year), tz_rule *rule AND int year)
|
||
{
|
||
register time_t t;
|
||
int y;
|
||
|
||
if (year != -1 && rule->computed_for == year)
|
||
/* Operations on times in 1969 will be slower. Oh well. */
|
||
return 1;
|
||
|
||
/* First set T to January 1st, 0:00:00 GMT in YEAR. */
|
||
t = 0;
|
||
for (y = 1970; y < year; ++y)
|
||
t += SECSPERDAY * (__isleap (y) ? 366 : 365);
|
||
|
||
switch (rule->type)
|
||
{
|
||
case J1:
|
||
/* Jn - Julian day, 1 == January 1, 60 == March 1 even in leap years.
|
||
In non-leap years, or if the day number is 59 or less, just
|
||
add SECSPERDAY times the day number-1 to the time of
|
||
January 1, midnight, to get the day. */
|
||
t += (rule->d - 1) * SECSPERDAY;
|
||
if (rule->d >= 60 && __isleap (year))
|
||
t += SECSPERDAY;
|
||
break;
|
||
|
||
case J0:
|
||
/* n - Day of year.
|
||
Just add SECSPERDAY times the day number to the time of Jan 1st. */
|
||
t += rule->d * SECSPERDAY;
|
||
break;
|
||
|
||
case M:
|
||
/* Mm.n.d - Nth "Dth day" of month M. */
|
||
{
|
||
register int i, d, m1, yy0, yy1, yy2, dow;
|
||
register CONST unsigned short int *myday =
|
||
&__mon_yday[__isleap (year)][rule->m];
|
||
|
||
/* First add SECSPERDAY for each day in months before M. */
|
||
t += myday[-1] * SECSPERDAY;
|
||
|
||
/* Use Zeller's Congruence to get day-of-week of first day of month. */
|
||
m1 = (rule->m + 9) % 12 + 1;
|
||
yy0 = (rule->m <= 2) ? (year - 1) : year;
|
||
yy1 = yy0 / 100;
|
||
yy2 = yy0 % 100;
|
||
dow = ((26 * m1 - 2) / 10 + 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
|
||
if (dow < 0)
|
||
dow += 7;
|
||
|
||
/* DOW is the day-of-week of the first day of the month. Get the
|
||
day-of-month (zero-origin) of the first DOW day of the month. */
|
||
d = rule->d - dow;
|
||
if (d < 0)
|
||
d += 7;
|
||
for (i = 1; i < rule->n; ++i)
|
||
{
|
||
if (d + 7 >= myday[0] - myday[-1])
|
||
break;
|
||
d += 7;
|
||
}
|
||
|
||
/* D is the day-of-month (zero-origin) of the day we want. */
|
||
t += d * SECSPERDAY;
|
||
}
|
||
break;
|
||
}
|
||
|
||
/* T is now the Epoch-relative time of 0:00:00 GMT on the day we want.
|
||
Just add the time of day and local offset from GMT, and we're done. */
|
||
|
||
rule->change = t + rule->offset + rule->secs;
|
||
rule->computed_for = year;
|
||
return 1;
|
||
}
|
||
|
||
|
||
/* Figure out the correct timezone for *TIMER and TM (which must be the same)
|
||
and set `__tzname', `__timezone', and `__daylight' accordingly.
|
||
Return nonzero on success, zero on failure. */
|
||
int
|
||
DEFUN(__tz_compute, (timer, tm),
|
||
time_t timer AND const struct tm *tm)
|
||
{
|
||
if (! __tzset_run)
|
||
__tzset ();
|
||
|
||
if (! compute_change (&tz_rules[0], 1900 + tm->tm_year) ||
|
||
! compute_change (&tz_rules[1], 1900 + tm->tm_year))
|
||
return 0;
|
||
|
||
__daylight = timer >= tz_rules[0].change && timer < tz_rules[1].change;
|
||
__timezone = tz_rules[__daylight ? 1 : 0].offset;
|
||
__tzname[0] = (char *) tz_rules[0].name;
|
||
__tzname[1] = (char *) tz_rules[1].name;
|
||
|
||
{
|
||
/* Keep __tzname_cur_max up to date. */
|
||
size_t len0 = strlen (__tzname[0]);
|
||
size_t len1 = strlen (__tzname[1]);
|
||
if (len0 > __tzname_cur_max)
|
||
__tzname_cur_max = len0;
|
||
if (len1 > __tzname_cur_max)
|
||
__tzname_cur_max = len1;
|
||
}
|
||
|
||
return 1;
|
||
}
|
||
|
||
#include <libc-lock.h>
|
||
|
||
/* This locks all the state variables in tzfile.c and this file. */
|
||
__libc_lock_define (, __tzset_lock)
|
||
|
||
/* Reinterpret the TZ environment variable and set `tzname'. */
|
||
#undef tzset
|
||
|
||
void
|
||
#ifdef weak_function
|
||
weak_function
|
||
#endif
|
||
tzset (void)
|
||
{
|
||
__libc_lock_lock (__tzset_lock);
|
||
__tzset ();
|
||
__libc_lock_unlock (__tzset_lock);
|
||
}
|