initial import

1 files changed, 487 insertions, 0 deletions

diff --git a/time/tzset.c b/time/tzset.c
new file mode 100644
index 0000000000..e4d5209e88
--- /dev/null
+++ b/time/tzset.c
@@ -0,0 +1,487 @@
+/* Copyright (C) 1991, 1992, 1993, 1994, 1995 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 <localeinfo.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_lengths[2][12];
+
+#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));
+
+#ifndef	HAVE_WEAK_SYMBOLS
+#define	__tzname	tzname
+#define	__daylight	daylight
+#define	__timezone	timezone
+#else
+weak_alias (__tzname, tzname)
+weak_alias (__daylight, daylight)
+weak_alias (__timezone, timezone)
+#endif
+
+char *__tzname[2] = { (char *) "GMT", (char *) "GMT" };
+int __daylight = 0;
+long int __timezone = 0L;
+
+
+#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);
+  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 = getenv("TZ");
+
+  if (tz != NULL && *tz == ':')
+    {
+      __tzfile_read(tz + 1);
+      if (__use_tzfile)
+	{
+	  __tzset_run = 1;
+	  return;
+	}
+      else
+	tz = NULL;
+    }
+
+  if (tz == NULL || *tz == '\0')
+    tz = _time_info->tz;
+  if (tz == NULL || *tz == '\0')
+    {
+      __tzfile_read((char *) NULL);
+      if (!__use_tzfile)
+	{
+	  size_t len = strlen(_time_info->ut0) + 1;
+	  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, _time_info->ut0, len);
+	  memcpy((PTR) tz_rules[1].name, _time_info->ut0, 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 GMT.  */
+  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 GMT.  */
+  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, 12) * 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, 12) * (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.  */
+long int __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;
+
+	/* First add SECSPERDAY for each day in months before M.  */
+	for (i = 0; i < rule->m - 1; ++i)
+	  t += __mon_lengths[__isleap (year)][i] * 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 >= __mon_lengths[__isleap (year)][rule->m - 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;
+}
+
+weak_alias (__tzset, tzset)