lib/libc/compat/gen/compat_timezone.c

   1 /*      $NetBSD: compat_timezone.c,v 1.3 2009/01/11 02:46:25 christos Exp $     */
   2
   3 /*
   4  * Copyright (c) 1987, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 #if 0
  35 static char sccsid[] = "@(#)timezone.c  8.1 (Berkeley) 6/4/93";
  36 #else
  37 __RCSID("$NetBSD: compat_timezone.c,v 1.3 2009/01/11 02:46:25 christos Exp $");
  38 #endif
  39 #endif /* LIBC_SCCS and not lint */
  40
  41 #define __LIBC12_SOURCE__
  42
  43 #include "namespace.h"
  44 #include <sys/types.h>
  45 #include <time.h>
  46 #include <compat/include/time.h>
  47 #include <stdio.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50 #include <tzfile.h>
  51
  52 __warn_references(timezone,
  53      "warning: reference to compatibility timezone; include <time.h> to generate correct reference")
  54
  55 /*
  56  * timezone --
  57  *      The arguments are the number of minutes of time you are westward
  58  *      from Greenwich and whether DST is in effect.  It returns a string
  59  *      giving the name of the local timezone.  Should be replaced, in the
  60  *      application code, by a call to localtime.
  61  */
  62
  63 char *_tztab(int, int);
  64
  65 static char     czone[TZ_MAX_CHARS];            /* space for zone name */
  66
  67 char *timezone(int, int);
  68 char *
  69 timezone(int zone, int dst)
  70 {
  71         char    *beg,
  72                         *end;
  73
  74         if ((beg = getenv("TZNAME")) != NULL) { /* set in environment */
  75                 if ((end = strchr(beg, ',')) != NULL) { /* "PST,PDT" */
  76                         if (dst)
  77                                 return(++end);
  78                         *end = '\0';
  79                         (void)strlcpy(czone, beg, sizeof(czone));
  80                         *end = ',';
  81                         return(czone);
  82                 }
  83                 return(beg);
  84         }
  85         return(_tztab(zone,dst));       /* default: table or created zone */
  86 }
  87
  88 static const struct zone {
  89         int             offset;
  90         const char      *stdzone;
  91         const char      *dlzone;
  92 } zonetab[] = {
  93         { -1*60,        "MET",  "MET DST" },    /* Middle European */
  94         { -2*60,        "EET",  "EET DST" },    /* Eastern European */
  95         { 4*60,         "AST",  "ADT" },        /* Atlantic */
  96         { 5*60,         "EST",  "EDT" },        /* Eastern */
  97         { 6*60,         "CST",  "CDT" },        /* Central */
  98         { 7*60,         "MST",  "MDT" },        /* Mountain */
  99         { 8*60,         "PST",  "PDT" },        /* Pacific */
 100 #ifdef notdef
 101         /* there's no way to distinguish this from WET */
 102         { 0,            "GMT",  0 },            /* Greenwich */
 103 #endif
 104         { 0*60,         "WET",  "WET DST" },    /* Western European */
 105         { -10*60,       "EST",  "EST" },        /* Aust: Eastern */
 106         { -10*60+30,    "CST",  "CST" },        /* Aust: Central */
 107         { -8*60,        "WST",  0 },            /* Aust: Western */
 108         { -1,           NULL,   NULL }
 109 };
 110
 111 /*
 112  * _tztab --
 113  *      check static tables or create a new zone name; broken out so that
 114  *      we can make a guess as to what the zone is if the standard tables
 115  *      aren't in place in /etc.  DO NOT USE THIS ROUTINE OUTSIDE OF THE
 116  *      STANDARD LIBRARY.
 117  */
 118 char *
 119 _tztab(zone,dst)
 120         int     zone;
 121         int     dst;
 122 {
 123         const struct zone       *zp;
 124         char    sign;
 125
 126         for (zp = zonetab; zp->offset != -1;++zp)       /* static tables */
 127                 if (zp->offset == zone) {
 128                         if (dst && zp->dlzone)
 129                                 return __UNCONST(zp->dlzone);
 130                         if (!dst && zp->stdzone)
 131                                 return __UNCONST(zp->stdzone);
 132                 }
 133
 134         if (zone < 0) {                                 /* create one */
 135                 zone = -zone;
 136                 sign = '+';
 137         }
 138         else
 139                 sign = '-';
 140         (void)snprintf(czone, TZ_MAX_CHARS, "GMT%c%d:%02d", sign, zone / 60,
 141              zone % 60);
 142         return(czone);
 143 }