xref: /illumos-gate/usr/src/contrib/ast/src/lib/libast/string/chrtoi.c (revision b30d193948be5a7794d7ae3ba0ed9c2f72c88e0f)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *          Copyright (c) 1985-2011 AT&T Intellectual Property          *
5 *                      and is licensed under the                       *
6 *                 Eclipse Public License, Version 1.0                  *
7 *                    by AT&T Intellectual Property                     *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *          http://www.eclipse.org/org/documents/epl-v10.html           *
11 *         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
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  * convert a 0 terminated character constant string to an int
28  */
29 
30 #include <ast.h>
31 
32 int
chrtoi(register const char * s)33 chrtoi(register const char* s)
34 {
35 	register int	c;
36 	register int	n;
37 	register int	x;
38 	char*		p;
39 
40 	c = 0;
41 	for (n = 0; n < sizeof(int) * CHAR_BIT; n += CHAR_BIT)
42 	{
43 		switch (x = *((unsigned char*)s++))
44 		{
45 		case '\\':
46 			x = chresc(s - 1, &p);
47 			s = (const char*)p;
48 			break;
49 		case 0:
50 			return(c);
51 		}
52 		c = (c << CHAR_BIT) | x;
53 	}
54 	return(c);
55 }
56