xref: /f-stack/tools/compat/strlcat.c (revision df6ad731)
1*df6ad731Slogwang /*	$OpenBSD: strlcat.c,v 1.2 1999/06/17 16:28:58 millert Exp $	*/
2*df6ad731Slogwang 
3*df6ad731Slogwang /*-
4*df6ad731Slogwang  * Copyright (c) 1998 Todd C. Miller <[email protected]>
5*df6ad731Slogwang  * All rights reserved.
6*df6ad731Slogwang  *
7*df6ad731Slogwang  * Redistribution and use in source and binary forms, with or without
8*df6ad731Slogwang  * modification, are permitted provided that the following conditions
9*df6ad731Slogwang  * are met:
10*df6ad731Slogwang  * 1. Redistributions of source code must retain the above copyright
11*df6ad731Slogwang  *    notice, this list of conditions and the following disclaimer.
12*df6ad731Slogwang  * 2. Redistributions in binary form must reproduce the above copyright
13*df6ad731Slogwang  *    notice, this list of conditions and the following disclaimer in the
14*df6ad731Slogwang  *    documentation and/or other materials provided with the distribution.
15*df6ad731Slogwang  * 3. The name of the author may not be used to endorse or promote products
16*df6ad731Slogwang  *    derived from this software without specific prior written permission.
17*df6ad731Slogwang  *
18*df6ad731Slogwang  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
19*df6ad731Slogwang  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
20*df6ad731Slogwang  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
21*df6ad731Slogwang  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22*df6ad731Slogwang  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23*df6ad731Slogwang  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24*df6ad731Slogwang  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25*df6ad731Slogwang  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
26*df6ad731Slogwang  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
27*df6ad731Slogwang  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28*df6ad731Slogwang  */
29*df6ad731Slogwang 
30*df6ad731Slogwang #include <string.h>
31*df6ad731Slogwang #include "compat.h"
32*df6ad731Slogwang 
33*df6ad731Slogwang /*
34*df6ad731Slogwang  * Appends src to string dst of size siz (unlike strncat, siz is the
35*df6ad731Slogwang  * full size of dst, not space left).  At most siz-1 characters
36*df6ad731Slogwang  * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
37*df6ad731Slogwang  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
38*df6ad731Slogwang  * If retval >= siz, truncation occurred.
39*df6ad731Slogwang  */
40*df6ad731Slogwang size_t
strlcat(dst,src,siz)41*df6ad731Slogwang strlcat(dst, src, siz)
42*df6ad731Slogwang 	char *dst;
43*df6ad731Slogwang 	const char *src;
44*df6ad731Slogwang 	size_t siz;
45*df6ad731Slogwang {
46*df6ad731Slogwang 	char *d = dst;
47*df6ad731Slogwang 	const char *s = src;
48*df6ad731Slogwang 	size_t n = siz;
49*df6ad731Slogwang 	size_t dlen;
50*df6ad731Slogwang 
51*df6ad731Slogwang 	/* Find the end of dst and adjust bytes left but don't go past end */
52*df6ad731Slogwang 	while (n-- != 0 && *d != '\0')
53*df6ad731Slogwang 		d++;
54*df6ad731Slogwang 	dlen = d - dst;
55*df6ad731Slogwang 	n = siz - dlen;
56*df6ad731Slogwang 
57*df6ad731Slogwang 	if (n == 0)
58*df6ad731Slogwang 		return(dlen + strlen(s));
59*df6ad731Slogwang 	while (*s != '\0') {
60*df6ad731Slogwang 		if (n != 1) {
61*df6ad731Slogwang 			*d++ = *s;
62*df6ad731Slogwang 			n--;
63*df6ad731Slogwang 		}
64*df6ad731Slogwang 		s++;
65*df6ad731Slogwang 	}
66*df6ad731Slogwang 	*d = '\0';
67*df6ad731Slogwang 
68*df6ad731Slogwang 	return(dlen + (s - src));	/* count does not include NUL */
69*df6ad731Slogwang }
70