xref: /titanic_44/usr/src/lib/libast/common/tm/tmgoff.c (revision b9e93c10c0a2a4bb069d38bb311021a9478c4711)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *          Copyright (c) 1985-2008 AT&T Intellectual Property          *
5 *                      and is licensed under the                       *
6 *                  Common Public License, Version 1.0                  *
7 *                    by AT&T Intellectual Property                     *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                 Glenn Fowler <gsf@research.att.com>                  *
18 *                  David Korn <dgk@research.att.com>                   *
19 *                   Phong Vo <kpv@research.att.com>                    *
20 *                                                                      *
21 ***********************************************************************/
22 #pragma prototyped
23 /*
24  * Glenn Fowler
25  * AT&T Bell Laboratories
26  *
27  * time conversion support
28  */
29 
30 #include <ast.h>
31 #include <tm.h>
32 #include <ctype.h>
33 
34 /*
35  * return minutes offset from absolute timezone expression
36  *
37  *	[[-+]hh[:mm[:ss]]]
38  *	[-+]hhmm
39  *
40  * if e is non-null then it points to the first unrecognized char in s
41  * d returned if no offset in s
42  */
43 
44 int
45 tmgoff(register const char* s, char** e, int d)
46 {
47 	register int	n = d;
48 	int		east;
49 	const char*	t = s;
50 
51 	if ((east = *s == '+') || *s == '-')
52 	{
53 		s++;
54 		if (isdigit(*s) && isdigit(*(s + 1)))
55 		{
56 			n = ((*s - '0') * 10 + (*(s + 1) - '0')) * 60;
57 			s += 2;
58 			if (*s == ':')
59 				s++;
60 			if (isdigit(*s) && isdigit(*(s + 1)))
61 			{
62 				n += ((*s - '0') * 10 + (*(s + 1) - '0'));
63 				s += 2;
64 				if (*s == ':')
65 					s++;
66 				if (isdigit(*s) && isdigit(*(s + 1)))
67 					s += 2;
68 			}
69 			if (east)
70 				n = -n;
71 			t = s;
72 		}
73 	}
74 	if (e)
75 		*e = (char*)t;
76 	return n;
77 }
78