libs/basekit/source/PortableStrlcpy.c

   1 /*
   2  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *      notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *      notice, this list of conditions and the following disclaimer in the
  12  *      documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *      derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  17  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  18  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  19  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #include <sys/types.h>
  29 #include "PortableStrlcpy.h"
  30
  31 /*
  32  * Copy src to string dest of size len.  At most len-1 characters
  33  * will be copied.  Always NUL terminates (unless len == 0).
  34  * Returns strlen(src); if retval >= len, truncation occurred.
  35  */
  36 size_t PortableStrlcpy(char* dest, const char* src, size_t len)
  37 {
  38         char* d = dest;
  39         const char* s = src;
  40         size_t n = len;
  41
  42         /* Copy as many bytes as will fit */
  43         if (n != 0 && --n != 0)
  44         {
  45                 do
  46                 {
  47                         if ((*d++ = *s++) == 0)
  48                                 break;
  49                 } while (--n != 0);
  50         }
  51
  52         /* Not enough room in dest, add NUL and traverse rest of src */
  53         if (n == 0)
  54         {
  55                 if (len != 0)
  56                         *d = '\0'; /* NUL-terminate dest */
  57                 while (*s++);
  58         }
  59
  60         return (s - src - 1); /* count doesn't include NUL */
  61 }