1*4a5d661aSToomas Soome /* $OpenBSD: strlcat.c,v 1.15 2015/03/02 21:41:08 millert Exp $ */
2*4a5d661aSToomas Soome
3*4a5d661aSToomas Soome /*
4*4a5d661aSToomas Soome * Copyright (c) 1998, 2015 Todd C. Miller <Todd.Miller@courtesan.com>
5*4a5d661aSToomas Soome *
6*4a5d661aSToomas Soome * Permission to use, copy, modify, and distribute this software for any
7*4a5d661aSToomas Soome * purpose with or without fee is hereby granted, provided that the above
8*4a5d661aSToomas Soome * copyright notice and this permission notice appear in all copies.
9*4a5d661aSToomas Soome *
10*4a5d661aSToomas Soome * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11*4a5d661aSToomas Soome * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12*4a5d661aSToomas Soome * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13*4a5d661aSToomas Soome * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14*4a5d661aSToomas Soome * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15*4a5d661aSToomas Soome * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16*4a5d661aSToomas Soome * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17*4a5d661aSToomas Soome */
18*4a5d661aSToomas Soome
19*4a5d661aSToomas Soome #include <sys/cdefs.h>
20*4a5d661aSToomas Soome __FBSDID("$FreeBSD$");
21*4a5d661aSToomas Soome
22*4a5d661aSToomas Soome #include <sys/types.h>
23*4a5d661aSToomas Soome #include <string.h>
24*4a5d661aSToomas Soome
25*4a5d661aSToomas Soome /*
26*4a5d661aSToomas Soome * Appends src to string dst of size dsize (unlike strncat, dsize is the
27*4a5d661aSToomas Soome * full size of dst, not space left). At most dsize-1 characters
28*4a5d661aSToomas Soome * will be copied. Always NUL terminates (unless dsize <= strlen(dst)).
29*4a5d661aSToomas Soome * Returns strlen(src) + MIN(dsize, strlen(initial dst)).
30*4a5d661aSToomas Soome * If retval >= dsize, truncation occurred.
31*4a5d661aSToomas Soome */
32*4a5d661aSToomas Soome size_t
strlcat(char * __restrict dst,const char * __restrict src,size_t dsize)33*4a5d661aSToomas Soome strlcat(char * __restrict dst, const char * __restrict src, size_t dsize)
34*4a5d661aSToomas Soome {
35*4a5d661aSToomas Soome const char *odst = dst;
36*4a5d661aSToomas Soome const char *osrc = src;
37*4a5d661aSToomas Soome size_t n = dsize;
38*4a5d661aSToomas Soome size_t dlen;
39*4a5d661aSToomas Soome
40*4a5d661aSToomas Soome /* Find the end of dst and adjust bytes left but don't go past end. */
41*4a5d661aSToomas Soome while (n-- != 0 && *dst != '\0')
42*4a5d661aSToomas Soome dst++;
43*4a5d661aSToomas Soome dlen = dst - odst;
44*4a5d661aSToomas Soome n = dsize - dlen;
45*4a5d661aSToomas Soome
46*4a5d661aSToomas Soome if (n-- == 0)
47*4a5d661aSToomas Soome return(dlen + strlen(src));
48*4a5d661aSToomas Soome while (*src != '\0') {
49*4a5d661aSToomas Soome if (n != 0) {
50*4a5d661aSToomas Soome *dst++ = *src;
51*4a5d661aSToomas Soome n--;
52*4a5d661aSToomas Soome }
53*4a5d661aSToomas Soome src++;
54*4a5d661aSToomas Soome }
55*4a5d661aSToomas Soome *dst = '\0';
56*4a5d661aSToomas Soome
57*4a5d661aSToomas Soome return(dlen + (src - osrc)); /* count does not include NUL */
58*4a5d661aSToomas Soome }
59