1 /* $NetBSD: compat_timezone.c,v 1.5 2024/01/20 14:52:45 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 1.5 2024/01/20 14:52:45 christos Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 #define __LIBC12_SOURCE__ 42 #define __TIMEZONE_FUNCTION__ 43 44 #include "namespace.h" 45 #include <sys/types.h> 46 #include <time.h> 47 #include <compat/include/time.h> 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <tzfile.h> 52 53 __warn_references(timezone, 54 "warning: reference to compatibility timezone; include <time.h> to generate correct reference") 55 56 /* 57 * timezone -- 58 * The arguments are the number of minutes of time you are westward 59 * from Greenwich and whether DST is in effect. It returns a string 60 * giving the name of the local timezone. Should be replaced, in the 61 * application code, by a call to localtime. 62 */ 63 64 static char czone[TZ_MAX_CHARS]; /* space for zone name */ 65 66 char * 67 timezone(int zone, int dst) 68 { 69 char *beg, 70 *end; 71 72 if ((beg = getenv("TZNAME")) != NULL) { /* set in environment */ 73 if ((end = strchr(beg, ',')) != NULL) { /* "PST,PDT" */ 74 if (dst) 75 return(++end); 76 *end = '\0'; 77 (void)strlcpy(czone, beg, sizeof(czone)); 78 *end = ','; 79 return(czone); 80 } 81 return(beg); 82 } 83 return(_tztab(zone,dst)); /* default: table or created zone */ 84 } 85 86 static const struct zone { 87 int offset; 88 const char *stdzone; 89 const char *dlzone; 90 } zonetab[] = { 91 { -1*60, "MET", "MET DST" }, /* Middle European */ 92 { -2*60, "EET", "EET DST" }, /* Eastern European */ 93 { 4*60, "AST", "ADT" }, /* Atlantic */ 94 { 5*60, "EST", "EDT" }, /* Eastern */ 95 { 6*60, "CST", "CDT" }, /* Central */ 96 { 7*60, "MST", "MDT" }, /* Mountain */ 97 { 8*60, "PST", "PDT" }, /* Pacific */ 98 #ifdef notdef 99 /* there's no way to distinguish this from WET */ 100 { 0, "GMT", 0 }, /* Greenwich */ 101 #endif 102 { 0*60, "WET", "WET DST" }, /* Western European */ 103 { -10*60, "EST", "EST" }, /* Aust: Eastern */ 104 { -10*60+30, "CST", "CST" }, /* Aust: Central */ 105 { -8*60, "WST", 0 }, /* Aust: Western */ 106 { -1, NULL, NULL } 107 }; 108 109 /* 110 * _tztab -- 111 * check static tables or create a new zone name; broken out so that 112 * we can make a guess as to what the zone is if the standard tables 113 * aren't in place in /etc. DO NOT USE THIS ROUTINE OUTSIDE OF THE 114 * STANDARD LIBRARY. 115 */ 116 char * 117 _tztab(int zone, int dst) 118 { 119 const struct zone *zp; 120 char sign; 121 122 for (zp = zonetab; zp->offset != -1;++zp) /* static tables */ 123 if (zp->offset == zone) { 124 if (dst && zp->dlzone) 125 return __UNCONST(zp->dlzone); 126 if (!dst && zp->stdzone) 127 return __UNCONST(zp->stdzone); 128 } 129 130 if (zone < 0) { /* create one */ 131 zone = -zone; 132 sign = '+'; 133 } 134 else 135 sign = '-'; 136 (void)snprintf(czone, TZ_MAX_CHARS, "GMT%c%d:%02d", sign, zone / 60, 137 zone % 60); 138 return(czone); 139 } 140