150 lines
4.5 KiB
C
150 lines
4.5 KiB
C
/* $NetBSD: timezone.c,v 1.14 2000/01/23 07:37:47 mycroft Exp $ */
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/*
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* Copyright (c) 1987, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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#if defined(LIBC_SCCS) && !defined(lint)
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#if 0
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static char sccsid[] = "@(#)timezone.c 8.1 (Berkeley) 6/4/93";
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#else
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__RCSID("$NetBSD: timezone.c,v 1.14 2000/01/23 07:37:47 mycroft Exp $");
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#endif
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#endif /* LIBC_SCCS and not lint */
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#include "namespace.h"
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#include <sys/types.h>
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#include <sys/time.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <tzfile.h>
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#if 0
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#ifdef __weak_alias
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__weak_alias(timezone,_timezone)
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#endif
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#endif
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/*
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* timezone --
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* The arguments are the number of minutes of time you are westward
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* from Greenwich and whether DST is in effect. It returns a string
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* giving the name of the local timezone. Should be replaced, in the
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* application code, by a call to localtime.
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*/
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char *_tztab __P((int, int));
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static char czone[TZ_MAX_CHARS]; /* space for zone name */
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char *
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timezone(zone, dst)
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int zone,
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dst;
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{
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char *beg,
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*end;
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if ((beg = getenv("TZNAME")) != NULL) { /* set in environment */
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if ((end = strchr(beg, ',')) != NULL) { /* "PST,PDT" */
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if (dst)
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return(++end);
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*end = '\0';
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(void)strncpy(czone,beg,sizeof(czone) - 1);
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czone[sizeof(czone) - 1] = '\0';
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*end = ',';
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return(czone);
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}
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return(beg);
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}
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return(_tztab(zone,dst)); /* default: table or created zone */
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}
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static const struct zone {
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int offset;
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char *stdzone;
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char *dlzone;
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} zonetab[] = {
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{ -1*60, "MET", "MET DST" }, /* Middle European */
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{ -2*60, "EET", "EET DST" }, /* Eastern European */
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{ 4*60, "AST", "ADT" }, /* Atlantic */
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{ 5*60, "EST", "EDT" }, /* Eastern */
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{ 6*60, "CST", "CDT" }, /* Central */
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{ 7*60, "MST", "MDT" }, /* Mountain */
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{ 8*60, "PST", "PDT" }, /* Pacific */
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#ifdef notdef
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/* there's no way to distinguish this from WET */
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{ 0, "GMT", 0 }, /* Greenwich */
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#endif
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{ 0*60, "WET", "WET DST" }, /* Western European */
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{ -10*60, "EST", "EST" }, /* Aust: Eastern */
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{ -10*60+30, "CST", "CST" }, /* Aust: Central */
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{ -8*60, "WST", 0 }, /* Aust: Western */
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{ -1, NULL, NULL }
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};
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/*
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* _tztab --
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* check static tables or create a new zone name; broken out so that
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* we can make a guess as to what the zone is if the standard tables
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* aren't in place in /etc. DO NOT USE THIS ROUTINE OUTSIDE OF THE
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* STANDARD LIBRARY.
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*/
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char *
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_tztab(zone,dst)
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int zone;
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int dst;
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{
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const struct zone *zp;
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char sign;
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for (zp = zonetab; zp->offset != -1;++zp) /* static tables */
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if (zp->offset == zone) {
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if (dst && zp->dlzone)
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return(zp->dlzone);
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if (!dst && zp->stdzone)
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return(zp->stdzone);
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}
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if (zone < 0) { /* create one */
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zone = -zone;
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sign = '+';
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}
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else
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sign = '-';
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(void)snprintf(czone, TZ_MAX_CHARS, "GMT%c%d:%02d", sign, zone / 60,
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zone % 60);
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return(czone);
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}
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