xref: /openbsd/usr.bin/rcs/rcstime.c (revision 264ca280)
1 /*	$OpenBSD: rcstime.c,v 1.5 2014/09/30 11:01:20 otto 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 	const char *errstr;
40 	struct tm *ltb;
41 	time_t now;
42 
43 	if (!strcmp(tz, "LT")) {
44 		now = mktime(&rdp->rd_date);
45 		ltb = localtime(&now);
46 		ltb->tm_hour += ((int)ltb->tm_gmtoff/3600);
47 		memcpy(tb, ltb, sizeof(*tb));
48 	} else {
49 		pos = 0;
50 		switch (*tz) {
51 		case '-':
52 			break;
53 		case '+':
54 			pos = 1;
55 			break;
56 		default:
57 			errx(1, "%s: not a known time zone", tz);
58 		}
59 
60 		h = (tz + 1);
61 		if ((m = strrchr(tz, ':')) != NULL)
62 			*(m++) = '\0';
63 
64 		memcpy(tb, &rdp->rd_date, sizeof(*tb));
65 
66 		tzone = strtonum(h, -23, 23, &errstr);
67 		if (errstr)
68 			errx(1, "%s: not a known time zone", tz);
69 
70 		if (pos) {
71 			tb->tm_hour += tzone;
72 			tb->tm_gmtoff += (tzone * 3600);
73 		} else {
74 			tb->tm_hour -= tzone;
75 			tb->tm_gmtoff -= (tzone * 3600);
76 		}
77 
78 		if ((tb->tm_hour >= 24) || (tb->tm_hour <= -24))
79 			tb->tm_hour = 0;
80 
81 		if (m != NULL) {
82 			tzone = strtonum(m, 0, 59, &errstr);
83 			if (errstr)
84 				errx(1, "%s: not a known minute", m);
85 
86 			if ((tb->tm_min + tzone) >= 60) {
87 				tb->tm_hour++;
88 				tb->tm_min -= (60 - tzone);
89 			} else
90 				tb->tm_min += tzone;
91 
92 			tb->tm_gmtoff += (tzone*60);
93 		}
94 	}
95 }
96