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 38 #include <sys/types.h> 39 #include <sys/time.h> 40 #include <stdio.h> 41 #include <stdlib.h> 42 #include <string.h> 43 #define TZ_MAX_CHARS 255 44 45 char *_tztab(); 46 47 /* 48 * timezone -- 49 * The arguments are the number of minutes of time you are westward 50 * from Greenwich and whether DST is in effect. It returns a string 51 * giving the name of the local timezone. Should be replaced, in the 52 * application code, by a call to localtime. 53 */ 54 55 static char czone[TZ_MAX_CHARS]; /* space for zone name */ 56 57 char * 58 timezone(zone, dst) 59 int zone, 60 dst; 61 { 62 register char *beg, 63 *end; 64 65 if ( (beg = getenv("TZNAME")) ) { /* set in environment */ 66 if ( (end = index(beg, ',')) ) {/* "PST,PDT" */ 67 if (dst) 68 return(++end); 69 *end = '\0'; 70 (void)strncpy(czone,beg,sizeof(czone) - 1); 71 czone[sizeof(czone) - 1] = '\0'; 72 *end = ','; 73 return(czone); 74 } 75 return(beg); 76 } 77 return(_tztab(zone,dst)); /* default: table or created zone */ 78 } 79 80 static struct zone { 81 int offset; 82 char *stdzone; 83 char *dlzone; 84 } zonetab[] = { 85 {-1*60, "MET", "MET DST"}, /* Middle European */ 86 {-2*60, "EET", "EET DST"}, /* Eastern European */ 87 {4*60, "AST", "ADT"}, /* Atlantic */ 88 {5*60, "EST", "EDT"}, /* Eastern */ 89 {6*60, "CST", "CDT"}, /* Central */ 90 {7*60, "MST", "MDT"}, /* Mountain */ 91 {8*60, "PST", "PDT"}, /* Pacific */ 92 #ifdef notdef 93 /* there's no way to distinguish this from WET */ 94 {0, "GMT", 0}, /* Greenwich */ 95 #endif 96 {0*60, "WET", "WET DST"}, /* Western European */ 97 {-10*60,"EST", "EST"}, /* Aust: Eastern */ 98 {-10*60+30,"CST", "CST"}, /* Aust: Central */ 99 {-8*60, "WST", 0}, /* Aust: Western */ 100 {-1} 101 }; 102 103 /* 104 * _tztab -- 105 * check static tables or create a new zone name; broken out so that 106 * we can make a guess as to what the zone is if the standard tables 107 * aren't in place in /etc. DO NOT USE THIS ROUTINE OUTSIDE OF THE 108 * STANDARD LIBRARY. 109 */ 110 char * 111 _tztab(zone,dst) 112 register int zone; 113 int dst; 114 { 115 register struct zone *zp; 116 register char sign; 117 118 for (zp = zonetab; zp->offset != -1;++zp) /* static tables */ 119 if (zp->offset == zone) { 120 if (dst && zp->dlzone) 121 return(zp->dlzone); 122 if (!dst && zp->stdzone) 123 return(zp->stdzone); 124 } 125 126 if (zone < 0) { /* create one */ 127 zone = -zone; 128 sign = '+'; 129 } 130 else 131 sign = '-'; 132 (void)snprintf(czone, sizeof(czone), 133 "GMT%c%d:%02d",sign,zone / 60,zone % 60); 134 return(czone); 135 } 136