strncat.c revision 1.2.4.2 1 1.2.4.2 yamt /* $NetBSD: strncat.c,v 1.2.4.2 2014/05/22 11:26:30 yamt Exp $ */
2 1.2.4.2 yamt
3 1.2.4.2 yamt /*-
4 1.2.4.2 yamt * Copyright (c) 1990, 1993
5 1.2.4.2 yamt * The Regents of the University of California. All rights reserved.
6 1.2.4.2 yamt *
7 1.2.4.2 yamt * This code is derived from software contributed to Berkeley by
8 1.2.4.2 yamt * Chris Torek.
9 1.2.4.2 yamt *
10 1.2.4.2 yamt * Redistribution and use in source and binary forms, with or without
11 1.2.4.2 yamt * modification, are permitted provided that the following conditions
12 1.2.4.2 yamt * are met:
13 1.2.4.2 yamt * 1. Redistributions of source code must retain the above copyright
14 1.2.4.2 yamt * notice, this list of conditions and the following disclaimer.
15 1.2.4.2 yamt * 2. Redistributions in binary form must reproduce the above copyright
16 1.2.4.2 yamt * notice, this list of conditions and the following disclaimer in the
17 1.2.4.2 yamt * documentation and/or other materials provided with the distribution.
18 1.2.4.2 yamt * 3. Neither the name of the University nor the names of its contributors
19 1.2.4.2 yamt * may be used to endorse or promote products derived from this software
20 1.2.4.2 yamt * without specific prior written permission.
21 1.2.4.2 yamt *
22 1.2.4.2 yamt * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 1.2.4.2 yamt * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 1.2.4.2 yamt * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 1.2.4.2 yamt * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 1.2.4.2 yamt * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 1.2.4.2 yamt * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 1.2.4.2 yamt * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 1.2.4.2 yamt * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 1.2.4.2 yamt * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 1.2.4.2 yamt * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 1.2.4.2 yamt * SUCH DAMAGE.
33 1.2.4.2 yamt */
34 1.2.4.2 yamt
35 1.2.4.2 yamt #include <sys/cdefs.h>
36 1.2.4.2 yamt #if defined(LIBC_SCCS) && !defined(lint)
37 1.2.4.2 yamt #if 0
38 1.2.4.2 yamt static char sccsid[] = "@(#)strncat.c 8.1 (Berkeley) 6/4/93";
39 1.2.4.2 yamt #else
40 1.2.4.2 yamt __RCSID("$NetBSD: strncat.c,v 1.2.4.2 2014/05/22 11:26:30 yamt Exp $");
41 1.2.4.2 yamt #endif
42 1.2.4.2 yamt #endif /* LIBC_SCCS and not lint */
43 1.2.4.2 yamt
44 1.2.4.2 yamt #if !defined(_KERNEL) && !defined(_STANDALONE)
45 1.2.4.2 yamt #include <assert.h>
46 1.2.4.2 yamt #include <string.h>
47 1.2.4.2 yamt #else
48 1.2.4.2 yamt #include <lib/libkern/libkern.h>
49 1.2.4.2 yamt #endif
50 1.2.4.2 yamt
51 1.2.4.2 yamt #ifdef _FORTIFY_SOURCE
52 1.2.4.2 yamt #undef strncat
53 1.2.4.2 yamt #endif
54 1.2.4.2 yamt
55 1.2.4.2 yamt /*
56 1.2.4.2 yamt * Concatenate src on the end of dst. At most strlen(dst)+n+1 bytes
57 1.2.4.2 yamt * are written at dst (at most n+1 bytes being appended). Return dst.
58 1.2.4.2 yamt */
59 1.2.4.2 yamt char *
60 1.2.4.2 yamt strncat(char *dst, const char *src, size_t n)
61 1.2.4.2 yamt {
62 1.2.4.2 yamt
63 1.2.4.2 yamt _DIAGASSERT(dst != NULL);
64 1.2.4.2 yamt _DIAGASSERT(src != NULL);
65 1.2.4.2 yamt
66 1.2.4.2 yamt if (n != 0) {
67 1.2.4.2 yamt char *d = dst;
68 1.2.4.2 yamt const char *s = src;
69 1.2.4.2 yamt
70 1.2.4.2 yamt while (*d != 0)
71 1.2.4.2 yamt d++;
72 1.2.4.2 yamt do {
73 1.2.4.2 yamt if ((*d = *s++) == 0)
74 1.2.4.2 yamt break;
75 1.2.4.2 yamt d++;
76 1.2.4.2 yamt } while (--n != 0);
77 1.2.4.2 yamt *d = 0;
78 1.2.4.2 yamt }
79 1.2.4.2 yamt return (dst);
80 1.2.4.2 yamt }
81