compat_strlcat.c

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