1 /*      $OpenBSD: strlcat.c,v 1.8 2001/05/13 15:40:15 deraadt Exp $     */
   2 
   3 /*
   4  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. The name of the author may not be used to endorse or promote products
  16  *    derived from this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  19  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  20  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  21  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  22  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  23  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  24  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  25  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  26  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  27  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29 
  30 #include "includes.h"
  31 #ifndef HAVE_STRLCAT
  32 
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 static char *rcsid = "$OpenBSD: strlcat.c,v 1.8 2001/05/13 15:40:15 deraadt Exp $";
  35 #endif /* LIBC_SCCS and not lint */
  36 
  37 #include <sys/types.h>
  38 #include <string.h>
  39 #include "strlcat.h"
  40 
  41 /*
  42  * Appends src to string dst of size siz (unlike strncat, siz is the
  43  * full size of dst, not space left).  At most siz-1 characters
  44  * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
  45  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
  46  * If retval >= siz, truncation occurred.
  47  */
  48 size_t
  49 strlcat(dst, src, siz)
  50         char *dst;
  51         const char *src;
  52         size_t siz;
  53 {
  54         register char *d = dst;
  55         register const char *s = src;
  56         register size_t n = siz;
  57         size_t dlen;
  58 
  59         /* Find the end of dst and adjust bytes left but don't go past end */
  60         while (n-- != 0 && *d != '\0')
  61                 d++;
  62         dlen = d - dst;
  63         n = siz - dlen;
  64 
  65         if (n == 0)
  66                 return(dlen + strlen(s));
  67         while (*s != '\0') {
  68                 if (n != 1) {
  69                         *d++ = *s;
  70                         n--;
  71                 }
  72                 s++;
  73         }
  74         *d = '\0';
  75 
  76         return(dlen + (s - src));       /* count does not include NUL */
  77 }
  78 
  79 #endif /* !HAVE_STRLCAT */
  80 
  81 #pragma ident   "%Z%%M% %I%     %E% SMI"