xref: /dflybsd-src/sys/libkern/strncat.c (revision 0579811519e2fb6eb6ea684c6d81c78f3293db7d)
1*05798115SSascha Wildner /*-
2*05798115SSascha Wildner  * Copyright (c) 1990, 1993
3*05798115SSascha Wildner  *	The Regents of the University of California.  All rights reserved.
4*05798115SSascha Wildner  *
5*05798115SSascha Wildner  * This code is derived from software contributed to Berkeley by
6*05798115SSascha Wildner  * Chris Torek.
7*05798115SSascha Wildner  *
8*05798115SSascha Wildner  * Redistribution and use in source and binary forms, with or without
9*05798115SSascha Wildner  * modification, are permitted provided that the following conditions
10*05798115SSascha Wildner  * are met:
11*05798115SSascha Wildner  * 1. Redistributions of source code must retain the above copyright
12*05798115SSascha Wildner  *    notice, this list of conditions and the following disclaimer.
13*05798115SSascha Wildner  * 2. Redistributions in binary form must reproduce the above copyright
14*05798115SSascha Wildner  *    notice, this list of conditions and the following disclaimer in the
15*05798115SSascha Wildner  *    documentation and/or other materials provided with the distribution.
16*05798115SSascha Wildner  * 3. Neither the name of the University nor the names of its contributors
17*05798115SSascha Wildner  *    may be used to endorse or promote products derived from this software
18*05798115SSascha Wildner  *    without specific prior written permission.
19*05798115SSascha Wildner  *
20*05798115SSascha Wildner  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21*05798115SSascha Wildner  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22*05798115SSascha Wildner  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23*05798115SSascha Wildner  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24*05798115SSascha Wildner  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25*05798115SSascha Wildner  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26*05798115SSascha Wildner  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27*05798115SSascha Wildner  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28*05798115SSascha Wildner  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29*05798115SSascha Wildner  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30*05798115SSascha Wildner  * SUCH DAMAGE.
31*05798115SSascha Wildner  *
32*05798115SSascha Wildner  * @(#)strncat.c	8.1 (Berkeley) 6/4/93
33*05798115SSascha Wildner  * $FreeBSD: src/lib/libc/string/strncat.c,v 1.7 2007/01/09 00:28:12 imp Exp $
34*05798115SSascha Wildner  */
35*05798115SSascha Wildner 
36*05798115SSascha Wildner #include <sys/types.h>
37*05798115SSascha Wildner #include <sys/libkern.h>
38*05798115SSascha Wildner 
39*05798115SSascha Wildner /*
40*05798115SSascha Wildner  * Concatenate src on the end of dst.  At most strlen(dst)+n+1 bytes
41*05798115SSascha Wildner  * are written at dst (at most n+1 bytes being appended).  Return dst.
42*05798115SSascha Wildner  */
43*05798115SSascha Wildner char *
strncat(char * __restrict dst,const char * __restrict src,size_t n)44*05798115SSascha Wildner strncat(char * __restrict dst, const char * __restrict src, size_t n)
45*05798115SSascha Wildner {
46*05798115SSascha Wildner 	if (n != 0) {
47*05798115SSascha Wildner 		char *d = dst;
48*05798115SSascha Wildner 		const char *s = src;
49*05798115SSascha Wildner 
50*05798115SSascha Wildner 		while (*d != 0)
51*05798115SSascha Wildner 			d++;
52*05798115SSascha Wildner 		do {
53*05798115SSascha Wildner 			if ((*d = *s++) == 0)
54*05798115SSascha Wildner 				break;
55*05798115SSascha Wildner 			d++;
56*05798115SSascha Wildner 		} while (--n != 0);
57*05798115SSascha Wildner 		*d = 0;
58*05798115SSascha Wildner 	}
59*05798115SSascha Wildner 	return (dst);
60*05798115SSascha Wildner }
61