1*22028508SToomas Soome /* $OpenBSD: strlcat.c,v 1.15 2015/03/02 21:41:08 millert Exp $ */
2*22028508SToomas Soome
3*22028508SToomas Soome /*
4*22028508SToomas Soome * Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
5*22028508SToomas Soome *
6*22028508SToomas Soome * Permission to use, copy, modify, and distribute this software for any
7*22028508SToomas Soome * purpose with or without fee is hereby granted, provided that the above
8*22028508SToomas Soome * copyright notice and this permission notice appear in all copies.
9*22028508SToomas Soome *
10*22028508SToomas Soome * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11*22028508SToomas Soome * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12*22028508SToomas Soome * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13*22028508SToomas Soome * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14*22028508SToomas Soome * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15*22028508SToomas Soome * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16*22028508SToomas Soome * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17*22028508SToomas Soome */
18*22028508SToomas Soome
19*22028508SToomas Soome #include <sys/cdefs.h>
20*22028508SToomas Soome __FBSDID("$FreeBSD$");
21*22028508SToomas Soome
22*22028508SToomas Soome #include <sys/types.h>
23*22028508SToomas Soome #include <string.h>
24*22028508SToomas Soome
25*22028508SToomas Soome /*
26*22028508SToomas Soome * Appends src to string dst of size dsize (unlike strncat, dsize is the
27*22028508SToomas Soome * full size of dst, not space left). At most dsize-1 characters
28*22028508SToomas Soome * will be copied. Always NUL terminates (unless dsize <= strlen(dst)).
29*22028508SToomas Soome * Returns strlen(src) + MIN(dsize, strlen(initial dst)).
30*22028508SToomas Soome * If retval >= dsize, truncation occurred.
31*22028508SToomas Soome */
32*22028508SToomas Soome size_t
strlcat(char * __restrict dst,const char * __restrict src,size_t dsize)33*22028508SToomas Soome strlcat(char * __restrict dst, const char * __restrict src, size_t dsize)
34*22028508SToomas Soome {
35*22028508SToomas Soome const char *odst = dst;
36*22028508SToomas Soome const char *osrc = src;
37*22028508SToomas Soome size_t n = dsize;
38*22028508SToomas Soome size_t dlen;
39*22028508SToomas Soome
40*22028508SToomas Soome /* Find the end of dst and adjust bytes left but don't go past end. */
41*22028508SToomas Soome while (n-- != 0 && *dst != '\0')
42*22028508SToomas Soome dst++;
43*22028508SToomas Soome dlen = dst - odst;
44*22028508SToomas Soome n = dsize - dlen;
45*22028508SToomas Soome
46*22028508SToomas Soome if (n-- == 0)
47*22028508SToomas Soome return(dlen + strlen(src));
48*22028508SToomas Soome while (*src != '\0') {
49*22028508SToomas Soome if (n != 0) {
50*22028508SToomas Soome *dst++ = *src;
51*22028508SToomas Soome n--;
52*22028508SToomas Soome }
53*22028508SToomas Soome src++;
54*22028508SToomas Soome }
55*22028508SToomas Soome *dst = '\0';
56*22028508SToomas Soome
57*22028508SToomas Soome return(dlen + (src - osrc)); /* count does not include NUL */
58*22028508SToomas Soome }
59