Line data    Source code

       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             : #if defined(LIBC_SCCS) && !defined(lint)
      31             : static char *rcsid = "$OpenBSD: strlcat.c,v 1.8 2001/05/13 15:40:15 deraadt Exp $";
      32             : #endif /* LIBC_SCCS and not lint */
      33             : 
      34             : #include <sys/types.h>
      35             : #include <string.h>
      36             : 
      37             : /*
      38             :  * Appends src to string dst of size siz (unlike strncat, siz is the
      39             :  * full size of dst, not space left).  At most siz-1 characters
      40             :  * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
      41             :  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
      42             :  * If retval >= siz, truncation occurred.
      43             :  */
      44             : size_t
      45       49978 : strlcat(char *dst, const char *src, size_t siz)
      46             : {
      47       49978 :         register char *d = dst;
      48       49978 :         register const char *s = src;
      49       49978 :         register size_t n = siz;
      50       49978 :         size_t dlen;
      51             : 
      52             :         /* Find the end of dst and adjust bytes left but don't go past end */
      53     1682426 :         while (n-- != 0 && *d != '\0')
      54     1632448 :                 d++;
      55       49978 :         dlen = d - dst;
      56       49978 :         n = siz - dlen;
      57             : 
      58       49978 :         if (n == 0)
      59           1 :                 return(dlen + strlen(s));
      60      584162 :         while (*s != '\0') {
      61      534185 :                 if (n != 1) {
      62      534185 :                         *d++ = *s;
      63      534185 :                         n--;
      64             :                 }
      65      534185 :                 s++;
      66             :         }
      67       49977 :         *d = '\0';
      68             : 
      69       49977 :         return(dlen + (s - src));       /* count does not include NUL */
      70             : }