xref: /titanic_41/usr/src/lib/libast/common/comp/strncasecmp.c (revision b3697b90e692e3e5d859fb77d285d4c056d99eda)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *          Copyright (c) 1985-2010 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 #include <ast.h>
25 
26 #if _lib_strncasecmp
27 
28 NoN(strncasecmp)
29 
30 #else
31 
32 #include <ctype.h>
33 
34 #undef	strncasecmp
35 
36 int
37 strncasecmp(register const char* a, register const char* b, size_t n)
38 {
39 	register const char*	e;
40 	register int		ac;
41 	register int		bc;
42 	register int		d;
43 
44 	e = a + n;
45 	for (;;)
46 	{
47 		if (a >= e)
48 			return 0;
49 		ac = *a++;
50 		if (isupper(ac))
51 			ac = tolower(ac);
52 		bc = *b++;
53 		if (isupper(bc))
54 			bc = tolower(bc);
55 		if (d = ac - bc)
56 			return d;
57 		if (!ac)
58 			return 0;
59 	}
60 }
61 
62 #endif
63