Line data    Source code

       1             : /*
       2             :  * src/port/strlcat.c
       3             :  *
       4             :  *  $OpenBSD: strlcat.c,v 1.13 2005/08/08 08:05:37 espie Exp $  */
       5             : 
       6             : /*
       7             :  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
       8             :  *
       9             :  * Permission to use, copy, modify, and distribute this software for any
      10             :  * purpose with or without fee is hereby granted, provided that the above
      11             :  * copyright notice and this permission notice appear in all copies.
      12             :  *
      13             :  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
      14             :  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
      15             :  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
      16             :  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
      17             :  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
      18             :  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
      19             :  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
      20             :  */
      21             : 
      22             : #include "c.h"
      23             : 
      24             : 
      25             : /*
      26             :  * Appends src to string dst of size siz (unlike strncat, siz is the
      27             :  * full size of dst, not space left).  At most siz-1 characters
      28             :  * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
      29             :  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
      30             :  * If retval >= siz, truncation occurred.
      31             :  */
      32             : size_t
      33           5 : strlcat(char *dst, const char *src, size_t siz)
      34             : {
      35           5 :     char       *d = dst;
      36           5 :     const char *s = src;
      37           5 :     size_t      n = siz;
      38             :     size_t      dlen;
      39             : 
      40             :     /* Find the end of dst and adjust bytes left but don't go past end */
      41         422 :     while (n-- != 0 && *d != '\0')
      42         412 :         d++;
      43           5 :     dlen = d - dst;
      44           5 :     n = siz - dlen;
      45             : 
      46           5 :     if (n == 0)
      47           0 :         return (dlen + strlen(s));
      48          41 :     while (*s != '\0')
      49             :     {
      50          31 :         if (n != 1)
      51             :         {
      52          31 :             *d++ = *s;
      53          31 :             n--;
      54             :         }
      55          31 :         s++;
      56             :     }
      57           5 :     *d = '\0';
      58             : 
      59           5 :     return (dlen + (s - src));  /* count does not include NUL */
      60             : }