xref: /netbsd-src/lib/libc/string/strxfrm.c (revision ce0bb6e8d2e560ecacbe865a848624f94498063b)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Chris Torek.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #if defined(LIBC_SCCS) && !defined(lint)
38 /*static char *sccsid = "from: @(#)strxfrm.c	5.2 (Berkeley) 1/26/91";*/
39 static char *rcsid = "$Id: strxfrm.c,v 1.3 1993/08/26 00:52:02 jtc Exp $";
40 #endif /* LIBC_SCCS and not lint */
41 
42 #include <sys/cdefs.h>
43 #include <string.h>
44 
45 /*
46  * Transform src, storing the result in dst, such that
47  * strcmp() on transformed strings returns what strcoll()
48  * on the original untransformed strings would return.
49  */
50 size_t
51 strxfrm(dst, src, n)
52 	register char *dst;
53 	register const char *src;
54 	register size_t n;
55 {
56 	register size_t r = 0;
57 	register int c;
58 
59 	/*
60 	 * Since locales are unimplemented, this is just a copy.
61 	 */
62 	if (n != 0) {
63 		while ((c = *src++) != 0) {
64 			r++;
65 			if (--n == 0) {
66 				while (*src++ != 0)
67 					r++;
68 				break;
69 			}
70 			*dst++ = c;
71 		}
72 		*dst = 0;
73 	}
74 	return (r);
75 }
76