add directory gnu

gnu/glibc/glibc-1.03/time/__tzset.c

@@ -0,0 +1,436 @@
+/* Copyright (C) 1991, 1992 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>
+
+#ifndef	HAVE_GNU_LD
+#define	__tzname	tzname
+#define	__daylight	daylight
+#define	__timezone	timezone
+#endif
+
+extern int __use_tzfile;
+extern void EXFUN(__tzfile_read, (CONST char *file));
+extern int EXFUN(__tzfile_compute, (time_t, struct tm));
+
+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
+  {
+    CONST char *name;
+
+    /* When to change.  */
+    enum { J0, J1, M } type;	/* Interpretation of:  */
+    unsigned short int m, n, d;	/* Month, week, day.  */
+    unsigned int secs:17;	/* 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];
+
+static 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;
+    }
+
+  /* Get the standard timezone name.  */
+  tz_rules[0].name = (char *) malloc(strlen(tz) + 1);
+  if (tz_rules[0].name == NULL)
+    return;
+
+  if (sscanf(tz, "%[^0-9,+-]", tz_rules[0].name) != 1 ||
+      (l = strlen(tz_rules[0].name)) < 3)
+    return;
+
+  tz_rules[0].name = (char *) realloc((PTR) tz_rules[0].name, l + 1);
+  if (tz_rules[0].name == NULL)
+    return;
+
+  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')
+    tz_rules[1].name = "";
+  else
+    {
+      tz_rules[1].name = (char *) malloc(strlen(tz) + 1);
+      if (tz_rules[1].name == NULL)
+	return;
+      if (sscanf(tz, "%[^0-9,+-]", tz_rules[1].name) != 1 ||
+	  (l = strlen(tz_rules[1].name)) < 3)
+	return;
+      tz_rules[1].name = (char *) realloc((PTR) tz_rules[1].name, l + 1);
+      if (tz_rules[1].name == NULL)
+	return;
+    }
+
+  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 *= abs (tz_rules[0].offset);
+      hh = 1;
+
+    case 1:
+      mm = 0;
+    case 2:
+      ss = 0;
+    case 3:
+      break;
+    }
+  tz_rules[1].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;
+    }
+
+  /* If no standard or DST offset was given, default to GMT
+     for standard and one hour later than standard for DST.  */
+  if (*tz_rules[0].name == '\0')
+    tz_rules[0].offset = 0L;
+  if (*tz_rules[1].name == '\0')
+    tz_rules[1].offset = tz_rules[0].offset + (60 * 60);
+
+  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)
+	return;
+    }
+
+  /* Figure out the standard <-> DST rules.  */
+  for (whichrule = 0; whichrule < 2; ++whichrule)
+    {
+      register tz_rule *tzr = &tz_rules[whichrule];
+      
+      if (*tz != '\0' && *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->n = (unsigned short int) strtoul(tz, &end, 10);
+	  if (end == tz || tzr->n > 365)
+	    return;
+	  else if (tzr->type == J1 && tzr->n == 0)
+	    return;
+	  if (tzr->type == J1 && tzr->n == 60)
+	    /* Can't do February 29.  */
+	    ++tzr->n;
+	  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 "M3.1.0,M8.5.0".  */
+	  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:
+	      return;
+	    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;
+}
+
+/* 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 unsigned short int m = rule->m, n = rule->n, d = rule->d;
+  struct tm tbuf;
+  register time_t t;
+
+  if (year != -1 && rule->computed_for == year)
+    /* Operations on times in 1969 will be slower.  Oh well.  */
+    return 1;
+
+  memset((PTR) &tbuf, 0, sizeof(tbuf));
+  tbuf.tm_year = year;
+
+  if (rule->type == M)
+    {
+      /* Defined in _offtime.c.  */
+      extern CONST unsigned short int __mon_lengths[2][12];
+      unsigned short int ml = __mon_lengths[__isleap(tbuf.tm_year)][m - 1];
+      tbuf.tm_mon = m - 1;
+      if (n == 5)
+	tbuf.tm_mday = ml;
+      else
+	tbuf.tm_mday = max((n - 1) * 7, 1);
+      tbuf.tm_sec = rule->secs;
+      t = mktime(&tbuf);
+      if (t == (time_t) -1)
+	return 0;
+      if (tbuf.tm_wday != d)
+	{
+	  if (d > tbuf.tm_wday)
+	    {
+	      tbuf.tm_mday -= 7;
+	      tbuf.tm_mday += tbuf.tm_wday - d;
+	    }
+	  else
+	    tbuf.tm_mday -= tbuf.tm_wday - d;
+	  if (tbuf.tm_mday < 1)
+	    tbuf.tm_mday += 7;
+	  else
+	    if (tbuf.tm_mday > ml) tbuf.tm_mday -= 7;
+	  t = mktime(&tbuf);
+	  if (t == (time_t) -1)
+	    return 0;
+	}
+    }
+  else
+    {
+      tbuf.tm_mon = 0;
+      if (rule->type == J1)
+	--n;
+      tbuf.tm_mday = n;
+      tbuf.tm_sec = rule->secs;
+      t = mktime(&tbuf);
+      if (t == (time_t) -1)
+	return 0;
+    }
+
+  rule->change = t;
+  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 struct tm tm)
+{
+  if (!tzset_run)
+    __tzset();
+
+  if (__use_tzfile)
+    return __tzfile_compute(timer, tm);
+
+  if (!compute_change(&tz_rules[0], tm.tm_year) ||
+      !compute_change(&tz_rules[1], 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;
+
+  return 1;
+}
+
+
+long int
+DEFUN_VOID (__tzname_max)
+{
+  size_t len0 = strlen (__tzname[0]), len1 = strlen (__tzname[1]);
+  return len0 > len1 ? len0 : len1;
+}