xref: /openbsd/usr.bin/rcs/rcstime.c (revision 404b540a)
1 /*	$OpenBSD: rcstime.c,v 1.3 2007/02/27 07:59:13 xsa Exp $	*/
2 /*
3  * Copyright (c) 2006 Joris Vink <joris@openbsd.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. The name of the author may not be used to endorse or promote products
13  *    derived from this software without specific prior written permission.
14  *
15  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
16  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
17  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
18  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19  * EXEMPLARY, OR CONSEQUENTIAL  DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <err.h>
28 #include <stdlib.h>
29 #include <string.h>
30 
31 #include "rcs.h"
32 
33 void
34 rcs_set_tz(char *tz, struct rcs_delta *rdp, struct tm *tb)
35 {
36 	int tzone;
37 	int pos;
38 	char *h, *m;
39 	struct tm *ltb;
40 	time_t now;
41 
42 	if (!strcmp(tz, "LT")) {
43 		now = mktime(&rdp->rd_date);
44 		ltb = localtime(&now);
45 		ltb->tm_hour += ((int)ltb->tm_gmtoff/3600);
46 		memcpy(tb, ltb, sizeof(*tb));
47 	} else {
48 		pos = 0;
49 		switch (*tz) {
50 		case '-':
51 			break;
52 		case '+':
53 			pos = 1;
54 			break;
55 		default:
56 			errx(1, "%s: not a known time zone", tz);
57 		}
58 
59 		h = (tz + 1);
60 		if ((m = strrchr(tz, ':')) != NULL)
61 			*(m++) = '\0';
62 
63 		memcpy(tb, &rdp->rd_date, sizeof(*tb));
64 
65 		tzone = atoi(h);
66 		if ((tzone >= 24) && (tzone <= -24))
67 			errx(1, "%s: not a known time zone", tz);
68 
69 		if (pos) {
70 			tb->tm_hour += tzone;
71 			tb->tm_gmtoff += (tzone * 3600);
72 		} else {
73 			tb->tm_hour -= tzone;
74 			tb->tm_gmtoff -= (tzone * 3600);
75 		}
76 
77 		if ((tb->tm_hour >= 24) || (tb->tm_hour <= -24))
78 			tb->tm_hour = 0;
79 
80 		if (m != NULL) {
81 			tzone = atoi(m);
82 			if (tzone >= 60)
83 				errx(1, "%s: not a known time zone", tz);
84 
85 			if ((tb->tm_min + tzone) >= 60) {
86 				tb->tm_hour++;
87 				tb->tm_min -= (60 - tzone);
88 			} else
89 				tb->tm_min += tzone;
90 
91 			tb->tm_gmtoff += (tzone*60);
92 		}
93 	}
94 }
95