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/*	$OpenBSD: strlcat.c,v 1.19 2019/01/25 00:19:25 millert Exp $	*/
 
/* 
 * Copyright (c) 1998, 2015 Todd C. Miller <millert@openbsd.org>
 * 
 * Permission to use, copy, modify, and distribute this software for any 
 * purpose with or without fee is hereby granted, provided that the above 
 * copyright notice and this permission notice appear in all copies. 
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 
 */ 
 
#include <sys/types.h> 
#include <string.h> 
 
/* 
 * Appends src to string dst of size dsize (unlike strncat, dsize is the
 * full size of dst, not space left).  At most dsize-1 characters
 * will be copied.  Always NUL terminates (unless dsize <= strlen(dst)).
 * Returns strlen(src) + MIN(dsize, strlen(initial dst)).
 * If retval >= dsize, truncation occurred.
 */ 
size_t 
strlcat(char *dst, const char *src, size_t dsize)
{ 
	const char *odst = dst;
	const char *osrc = src;
	size_t n = dsize;
	size_t dlen;
 
	/* Find the end of dst and adjust bytes left but don't go past end. */
	while (n-- != 0 && *dst != '\0')
		dst++;
	dlen = dst - odst;
	n = dsize - dlen;
 
	if (n-- == 0)
		return(dlen + strlen(src));
	while (*src != '\0') {
		if (n != 0) {
			*dst++ = *src;
			n--;
		}
		src++;
	}
	*dst = '\0';
 
	return(dlen + (src - osrc));	/* count does not include NUL */
}