xref: /PHP-8.2/main/strlcat.c (revision 81d4d5dd)
1 /*
2   +----------------------------------------------------------------------+
3   | Copyright (c) The PHP Group                                          |
4   +----------------------------------------------------------------------+
5   | This source file is subject to version 3.01 of the PHP license,      |
6   | that is bundled with this package in the file LICENSE, and is        |
7   | available through the world-wide-web at the following url:           |
8   | https://www.php.net/license/3_01.txt                                 |
9   | If you did not receive a copy of the PHP license and are unable to   |
10   | obtain it through the world-wide-web, please send a note to          |
11   | license@php.net so we can mail you a copy immediately.               |
12   +----------------------------------------------------------------------+
13   | Author:                                                              |
14   +----------------------------------------------------------------------+
15 */
16 
17 #include "php.h"
18 
19 #ifdef USE_STRLCAT_PHP_IMPL
20 
21 /*     $OpenBSD: strlcat.c,v 1.18 2016/10/16 17:37:39 dtucker Exp $    */
22 
23 /*
24  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
25  * All rights reserved.
26  *
27  * Redistribution and use in source and binary forms, with or without
28  * modification, are permitted provided that the following conditions
29  * are met:
30  * 1. Redistributions of source code must retain the above copyright
31  *    notice, this list of conditions and the following disclaimer.
32  * 2. Redistributions in binary form must reproduce the above copyright
33  *    notice, this list of conditions and the following disclaimer in the
34  *    documentation and/or other materials provided with the distribution.
35  * 3. The name of the author may not be used to endorse or promote products
36  *    derived from this software without specific prior written permission.
37  *
38  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
39  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
40  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
41  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
42  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
43  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
44  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
45  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
46  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
47  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
48  */
49 
50 #if defined(LIBC_SCCS) && !defined(lint)
51 static const char *rcsid = "$OpenBSD: strlcat.c,v 1.17 2016/10/14 18:19:04 dtucker Exp $";
52 #endif /* LIBC_SCCS and not lint */
53 
54 #include <sys/types.h>
55 #include <string.h>
56 
57 /*
58  * Appends src to string dst of size siz (unlike strncat, siz is the
59  * full size of dst, not space left).  At most siz-1 characters
60  * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
61  * Returns strlen(src) + MIN(siz, strlen(initial dst).
62  * If retval >= siz, truncation occurred.
63  */
php_strlcat(char * dst,const char * src,size_t siz)64 PHPAPI size_t php_strlcat(char *dst, const char *src, size_t siz)
65 {
66 	const char *d = dst;
67 	const char *s = src;
68 	size_t n = siz;
69 	size_t dlen;
70 
71 	/* Find the end of dst and adjust bytes left but don't go past end */
72 	while (n-- != 0 && *dst != '\0')
73 		dst++;
74 	dlen = dst - d;
75 	n = siz - dlen;
76 
77 	if (n-- == 0)
78 		return(dlen + strlen(src));
79 	while (*src != '\0') {
80 		if (n != 0) {
81 			*dst++ = *src;
82 			n--;
83 		}
84 		src++;
85 	}
86 	*dst = '\0';
87 
88 	return(dlen + (src - s));
89 }
90 
91 #endif /* !HAVE_STRLCAT */
92