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      1 /*	$OpenBSD: strlcat.c,v 1.13 2005/08/08 08:05:37 espie Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1998 Todd C. Miller <Todd.Miller (at) courtesan.com>
      5  *
      6  * Permission to use, copy, modify, and distribute this software for any
      7  * purpose with or without fee is hereby granted, provided that the above
      8  * copyright notice and this permission notice appear in all copies.
      9  *
     10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
     11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
     13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     17  */
     18 
     19 /* OPENBSD ORIGINAL: lib/libc/string/strlcat.c */
     20 
     21 #include "includes.h"
     22 #ifndef HAVE_STRLCAT
     23 
     24 #include <sys/types.h>
     25 #include <string.h>
     26 
     27 /*
     28  * Appends src to string dst of size siz (unlike strncat, siz is the
     29  * full size of dst, not space left).  At most siz-1 characters
     30  * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
     31  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
     32  * If retval >= siz, truncation occurred.
     33  */
     34 size_t
     35 strlcat(char *dst, const char *src, size_t siz)
     36 {
     37 	char *d = dst;
     38 	const char *s = src;
     39 	size_t n = siz;
     40 	size_t dlen;
     41 
     42 	/* Find the end of dst and adjust bytes left but don't go past end */
     43 	while (n-- != 0 && *d != '\0')
     44 		d++;
     45 	dlen = d - dst;
     46 	n = siz - dlen;
     47 
     48 	if (n == 0)
     49 		return(dlen + strlen(s));
     50 	while (*s != '\0') {
     51 		if (n != 1) {
     52 			*d++ = *s;
     53 			n--;
     54 		}
     55 		s++;
     56 	}
     57 	*d = '\0';
     58 
     59 	return(dlen + (s - src));	/* count does not include NUL */
     60 }
     61 
     62 #endif /* !HAVE_STRLCAT */
     63