1 /* $NetBSD: compat_timezone.c,v 1.4 2012/03/20 17:05:59 matt 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 1.4 2012/03/20 17:05:59 matt 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 *
timezone(int zone,int dst)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 *
_tztab(int zone,int dst)119 _tztab(int zone, int dst)
120 {
121 const struct zone *zp;
122 char sign;
123
124 for (zp = zonetab; zp->offset != -1;++zp) /* static tables */
125 if (zp->offset == zone) {
126 if (dst && zp->dlzone)
127 return __UNCONST(zp->dlzone);
128 if (!dst && zp->stdzone)
129 return __UNCONST(zp->stdzone);
130 }
131
132 if (zone < 0) { /* create one */
133 zone = -zone;
134 sign = '+';
135 }
136 else
137 sign = '-';
138 (void)snprintf(czone, TZ_MAX_CHARS, "GMT%c%d:%02d", sign, zone / 60,
139 zone % 60);
140 return(czone);
141 }
142