xref: /onnv-gate/usr/src/lib/libast/common/tm/tmgoff.c (revision 4887:feebf9260c2e) 
1*4887Schin /***********************************************************************
2*4887Schin *                                                                      *
3*4887Schin *               This software is part of the ast package               *
4*4887Schin *           Copyright (c) 1985-2007 AT&T Knowledge Ventures            *
5*4887Schin *                      and is licensed under the                       *
6*4887Schin *                  Common Public License, Version 1.0                  *
7*4887Schin *                      by AT&T Knowledge Ventures                      *
8*4887Schin *                                                                      *
9*4887Schin *                A copy of the License is available at                 *
10*4887Schin *            http://www.opensource.org/licenses/cpl1.0.txt             *
11*4887Schin *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12*4887Schin *                                                                      *
13*4887Schin *              Information and Software Systems Research               *
14*4887Schin *                            AT&T Research                             *
15*4887Schin *                           Florham Park NJ                            *
16*4887Schin *                                                                      *
17*4887Schin *                 Glenn Fowler <gsf@research.att.com>                  *
18*4887Schin *                  David Korn <dgk@research.att.com>                   *
19*4887Schin *                   Phong Vo <kpv@research.att.com>                    *
20*4887Schin *                                                                      *
21*4887Schin ***********************************************************************/
22*4887Schin #pragma prototyped
23*4887Schin /*
24*4887Schin  * Glenn Fowler
25*4887Schin  * AT&T Bell Laboratories
26*4887Schin  *
27*4887Schin  * time conversion support
28*4887Schin  */
29*4887Schin 
30*4887Schin #include <ast.h>
31*4887Schin #include <tm.h>
32*4887Schin #include <ctype.h>
33*4887Schin 
34*4887Schin /*
35*4887Schin  * return minutes offset from absolute timezone expression
36*4887Schin  *
37*4887Schin  *	[[-+]hh[:mm[:ss]]]
38*4887Schin  *	[-+]hhmm
39*4887Schin  *
40*4887Schin  * if e is non-null then it points to the first unrecognized char in s
41*4887Schin  * d returned if no offset in s
42*4887Schin  */
43*4887Schin 
44*4887Schin int
45*4887Schin tmgoff(register const char* s, char** e, int d)
46*4887Schin {
47*4887Schin 	register int	n = d;
48*4887Schin 	int		east;
49*4887Schin 	const char*	t = s;
50*4887Schin 
51*4887Schin 	if ((east = *s == '+') || *s == '-')
52*4887Schin 	{
53*4887Schin 		s++;
54*4887Schin 		if (isdigit(*s) && isdigit(*(s + 1)))
55*4887Schin 		{
56*4887Schin 			n = ((*s - '0') * 10 + (*(s + 1) - '0')) * 60;
57*4887Schin 			s += 2;
58*4887Schin 			if (*s == ':')
59*4887Schin 				s++;
60*4887Schin 			if (isdigit(*s) && isdigit(*(s + 1)))
61*4887Schin 			{
62*4887Schin 				n += ((*s - '0') * 10 + (*(s + 1) - '0'));
63*4887Schin 				s += 2;
64*4887Schin 				if (*s == ':')
65*4887Schin 					s++;
66*4887Schin 				if (isdigit(*s) && isdigit(*(s + 1)))
67*4887Schin 					s += 2;
68*4887Schin 			}
69*4887Schin 			if (east)
70*4887Schin 				n = -n;
71*4887Schin 			t = s;
72*4887Schin 		}
73*4887Schin 	}
74*4887Schin 	if (e)
75*4887Schin 		*e = (char*)t;
76*4887Schin 	return n;
77*4887Schin }
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