xref: /optee_os/lib/libutils/ext/strlcat.c (revision bc420748bfc44a9e09000a3966fc59e9e0219df4)
1 /* This file is copied from newlib-1.19 */
2 
3 /*      $OpenBSD: strlcat.c,v 1.8 2001/05/13 15:40:15 deraadt Exp $        */
4 
5 /*
6  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. The name of the author may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
21  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
22  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
23  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #if defined(LIBC_SCCS) && !defined(lint)
33 static char *rcsid =
34 	"$OpenBSD: strlcat.c,v 1.8 2001/05/13 15:40:15 deraadt Exp $";
35 #endif /* LIBC_SCCS and not lint */
36 
37 #include <types_ext.h>
38 #include <string_ext.h>
39 /* #include <string.h> */
40 
41 size_t strlen(const char *s);
42 /*
43  * Appends src to string dst of size siz (unlike strncat, siz is the
44  * full size of dst, not space left).  At most siz-1 characters
45  * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
46  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
47  * If retval >= siz, truncation occurred.
48  */
49 size_t strlcat(char *dst, const char *src, size_t siz)
50 {
51 	register char *d = dst;
52 	register const char *s = src;
53 	register size_t n = siz;
54 	size_t dlen;
55 
56 	/* Find the end of dst and adjust bytes left but don't go past end */
57 	while (n-- != 0 && *d != '\0')
58 		d++;
59 	dlen = d - dst;
60 	n = siz - dlen;
61 
62 	if (n == 0)
63 		return dlen + strlen(s);
64 
65 	while (*s != '\0') {
66 		if (n != 1) {
67 			*d++ = *s;
68 			n--;
69 		}
70 		s++;
71 	}
72 	*d = '\0';
73 
74 	return dlen + (s - src);	/* count does not include NUL */
75 }
76