lib/libc/string/wcslcpy.c

   1 /*      $NetBSD: wcslcpy.c,v 1.3 2012/06/25 22:32:46 abs Exp $  */
   2 /*      from OpenBSD: strlcpy.c,v 1.4 1999/05/01 18:56:41 millert Exp   */
   3
   4 /*
   5  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  20  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  21  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  22  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  23  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  24  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  25  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  26  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  27  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  28  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include <sys/cdefs.h>
  32 #if defined(LIBC_SCCS) && !defined(lint)
  33 __RCSID("$NetBSD: wcslcpy.c,v 1.3 2012/06/25 22:32:46 abs Exp $");
  34 #endif /* LIBC_SCCS and not lint */
  35
  36 #include <sys/types.h>
  37 #include <assert.h>
  38 #include <wchar.h>
  39
  40 /*
  41  * Copy src to string dst of size siz.  At most siz-1 characters
  42  * will be copied.  Always NUL terminates (unless siz == 0).
  43  * Returns wcslen(src); if retval >= siz, truncation occurred.
  44  */
  45 size_t
  46 wcslcpy(wchar_t *dst, const wchar_t *src, size_t siz)
  47 {
  48         wchar_t *d = dst;
  49         const wchar_t *s = src;
  50         size_t n = siz;
  51
  52         _DIAGASSERT(dst != NULL);
  53         _DIAGASSERT(src != NULL);
  54
  55         /* Copy as many bytes as will fit */
  56         if (n != 0 && --n != 0) {
  57                 do {
  58                         if ((*d++ = *s++) == 0)
  59                                 break;
  60                 } while (--n != 0);
  61         }
  62
  63         /* Not enough room in dst, add NUL and traverse rest of src */
  64         if (n == 0) {
  65                 if (siz != 0)
  66                         *d = '\0';              /* NUL-terminate dst */
  67                 while (*s++)
  68                         ;
  69         }
  70
  71         return(s - src - 1);    /* count does not include NUL */
  72 }