usr/src/lib/libbc/libc/gen/4.2/timezone.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 1986 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28           /* from UCB 4.4 83/09/25 */
  29
  30 /*
  31  * The arguments are the number of minutes of time
  32  * you are westward from Greenwich and whether DST is in effect.
  33  * It returns a string
  34  * giving the name of the local timezone.
  35  *
  36  * Sorry, I don't know all the names.
  37  */
  38
  39 static struct zone {
  40         int     offset;
  41         char    *stdzone;
  42         char    *dlzone;
  43 } zonetab[] = {
  44         -12*60,    "NZST", "NZDT",      /* New Zealand */
  45         -10*60,    "EST",  "EST",       /* Aust: Eastern */
  46         -10*60+30, "CST",  "CST",       /* Aust: Central */
  47          -8*60,    "WST",  0,           /* Aust: Western */
  48          -9*60,    "JST",  0,           /* Japanese */
  49           0*60,    "GMT",  "BST",       /* Great Britain and Eire */
  50          -1*60,    "MET",  "MET DST",   /* Middle European */
  51          -2*60,    "EET",  "EET DST",   /* Eastern European */
  52           3*60+30, "NST",  "NDT",       /* Newfoundland */
  53           4*60,    "AST",  "ADT",       /* Atlantic */
  54           5*60,    "EST",  "EDT",       /* Eastern */
  55           6*60,    "CST",  "CDT",       /* Central */
  56           7*60,    "MST",  "MDT",       /* Mountain */
  57           8*60,    "PST",  "PDT",       /* Pacific */
  58           9*60,    "YST",  "YDT",       /* Yukon */
  59          10*60,    "HST",  "HDT",       /* Hawaiian */
  60         -1
  61 };
  62
  63 char *timezone(zone, dst)
  64 {
  65         register struct zone *zp;
  66         static char czone[10];
  67         char *sign;
  68         register char *p, *q;
  69         char *getenv(), *index();
  70
  71         if (p = getenv("TZNAME")) {
  72                 if (q = index(p, ',')) {
  73                         if (dst)
  74                                 return(++q);
  75                         else {
  76                                 *q = '\0';
  77                                 strncpy(czone, p, sizeof(czone)-1);
  78                                 czone[sizeof(czone)-1] = '\0';
  79                                 *q = ',';
  80                                 return (czone);
  81                         }
  82                 }
  83                 return(p);
  84         }
  85         for (zp=zonetab; zp->offset!=-1; zp++)
  86                 if (zp->offset==zone) {
  87                         if (dst && zp->dlzone)
  88                                 return(zp->dlzone);
  89                         if (!dst && zp->stdzone)
  90                                 return(zp->stdzone);
  91                 }
  92         if (zone<0) {
  93                 zone = -zone;
  94                 sign = "+";
  95         } else
  96                 sign = "-";
  97         sprintf(czone, "GMT%s%d:%02d", sign, zone/60, zone%60);
  98         return(czone);
  99 }