1 /* 2 * Copyright (c) 1987, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char sccsid[] = "@(#)timezone.c 8.1 (Berkeley) 6/4/93"; 36 #endif /* LIBC_SCCS and not lint */ 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include <sys/types.h> 41 #include <sys/time.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #define TZ_MAX_CHARS 255 46 47 char *_tztab(); 48 49 /* 50 * timezone -- 51 * The arguments are the number of minutes of time you are westward 52 * from Greenwich and whether DST is in effect. It returns a string 53 * giving the name of the local timezone. Should be replaced, in the 54 * application code, by a call to localtime. 55 */ 56 57 static char czone[TZ_MAX_CHARS]; /* space for zone name */ 58 59 char * 60 timezone(zone, dst) 61 int zone, 62 dst; 63 { 64 char *beg, 65 *end; 66 67 if ( (beg = getenv("TZNAME")) ) { /* set in environment */ 68 if ( (end = index(beg, ',')) ) {/* "PST,PDT" */ 69 if (dst) 70 return(++end); 71 *end = '\0'; 72 (void)strncpy(czone,beg,sizeof(czone) - 1); 73 czone[sizeof(czone) - 1] = '\0'; 74 *end = ','; 75 return(czone); 76 } 77 return(beg); 78 } 79 return(_tztab(zone,dst)); /* default: table or created zone */ 80 } 81 82 static struct zone { 83 int offset; 84 char *stdzone; 85 char *dlzone; 86 } zonetab[] = { 87 {-1*60, "MET", "MET DST"}, /* Middle European */ 88 {-2*60, "EET", "EET DST"}, /* Eastern European */ 89 {4*60, "AST", "ADT"}, /* Atlantic */ 90 {5*60, "EST", "EDT"}, /* Eastern */ 91 {6*60, "CST", "CDT"}, /* Central */ 92 {7*60, "MST", "MDT"}, /* Mountain */ 93 {8*60, "PST", "PDT"}, /* Pacific */ 94 #ifdef notdef 95 /* there's no way to distinguish this from WET */ 96 {0, "GMT", 0}, /* Greenwich */ 97 #endif 98 {0*60, "WET", "WET DST"}, /* Western European */ 99 {-10*60,"EST", "EST"}, /* Aust: Eastern */ 100 {-10*60+30,"CST", "CST"}, /* Aust: Central */ 101 {-8*60, "WST", 0}, /* Aust: Western */ 102 {-1} 103 }; 104 105 /* 106 * _tztab -- 107 * check static tables or create a new zone name; broken out so that 108 * we can make a guess as to what the zone is if the standard tables 109 * aren't in place in /etc. DO NOT USE THIS ROUTINE OUTSIDE OF THE 110 * STANDARD LIBRARY. 111 */ 112 char * 113 _tztab(zone,dst) 114 int zone; 115 int dst; 116 { 117 struct zone *zp; 118 char sign; 119 120 for (zp = zonetab; zp->offset != -1;++zp) /* static tables */ 121 if (zp->offset == zone) { 122 if (dst && zp->dlzone) 123 return(zp->dlzone); 124 if (!dst && zp->stdzone) 125 return(zp->stdzone); 126 } 127 128 if (zone < 0) { /* create one */ 129 zone = -zone; 130 sign = '+'; 131 } 132 else 133 sign = '-'; 134 (void)snprintf(czone, sizeof(czone), 135 "GMT%c%d:%02d",sign,zone / 60,zone % 60); 136 return(czone); 137 } 138