/*      Id: compat_strlcat.c,v 1.6 2020/06/15 20:49:57 schwarze Exp     */
/*      $OpenBSD: strlcat.c,v 1.19 2019/01/25 00:19:25 millert Exp $    */

/*
* Copyright (c) 1998, 2015 Todd C. Miller <[email protected]>
*
* 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 "config.h"

#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 */
}