string/FreeBSD/strlcpy.c

   1 /*      $OpenBSD: strlcpy.c,v 1.11 2006/05/05 15:27:38 millert Exp $    */
   2
   3 /*
   4  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <sys/cdefs.h>
  20 __FBSDID("$FreeBSD: src/lib/libc/string/strlcpy.c,v 1.11 2009/02/28 05:15:02 das Exp $");
  21
  22 #include <sys/types.h>
  23 #include <string.h>
  24
  25 /*
  26  * Copy src to string dst of size siz.  At most siz-1 characters
  27  * will be copied.  Always NUL terminates (unless siz == 0).
  28  * Returns strlen(src); if retval >= siz, truncation occurred.
  29  */
  30 size_t
  31 strlcpy(char * __restrict dst, const char * __restrict src, size_t siz)
  32 {
  33         char *d = dst;
  34         const char *s = src;
  35         size_t n = siz;
  36
  37         /* Copy as many bytes as will fit */
  38         if (n != 0) {
  39                 while (--n != 0) {
  40                         if ((*d++ = *s++) == '\0')
  41                                 break;
  42                 }
  43         }
  44
  45         /* Not enough room in dst, add NUL and traverse rest of src */
  46         if (n == 0) {
  47                 if (siz != 0)
  48                         *d = '\0';              /* NUL-terminate dst */
  49                 while (*s++)
  50                         ;
  51         }
  52
  53         return(s - src - 1);    /* count does not include NUL */
  54 }