newlib/libc/string/wcslcpy.c

   1 /*
   2 FUNCTION
   3         <<wcslcpy>>---copy a wide-character string to specified length
   4
   5 SYNOPSIS
   6         #include <wchar.h>
   7         size_t wcslcpy(wchar_t *<[dst]>, const wchar_t *<[src]>, size_t <[siz]>);
   8
   9 DESCRIPTION
  10         <<wcslcpy>> copies wide characters from <[src]> to <[dst]>
  11         such that up to <[siz]> - 1 characters are copied.  A
  12         terminating null is appended to the result, unless <[siz]>
  13         is zero.
  14
  15 RETURNS
  16         <<wcslcpy>> returns the number of wide characters in <[src]>,
  17         not including the terminating null wide character.  If the
  18         return value is greater than or equal to <[siz]>, then
  19         not all wide characters were copied from <[src]> and truncation
  20         occurred.
  21
  22 PORTABILITY
  23 No supporting OS subroutines are required.
  24 */
  25
  26 /*      $OpenBSD: wcslcpy.c,v 1.8 2019/01/25 00:19:25 millert Exp $     */
  27
  28 /*
  29  * Copyright (c) 1998, 2015 Todd C. Miller <millert@openbsd.org>
  30  *
  31  * Permission to use, copy, modify, and distribute this software for any
  32  * purpose with or without fee is hereby granted, provided that the above
  33  * copyright notice and this permission notice appear in all copies.
  34  *
  35  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  36  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  37  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  38  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  39  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  40  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  41  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  42  */
  43
  44 #include <sys/types.h>
  45 #include <wchar.h>
  46
  47 /*
  48  * Copy string src to buffer dst of size dsize.  At most dsize-1
  49  * chars will be copied.  Always NUL terminates (unless dsize == 0).
  50  * Returns wcslen(src); if retval >= dsize, truncation occurred.
  51  */
  52 size_t
  53 wcslcpy (wchar_t *dst,
  54         const wchar_t *src,
  55         size_t dsize)
  56 {
  57         const wchar_t *osrc = src;
  58         size_t nleft = dsize;
  59
  60         /* Copy as many bytes as will fit. */
  61         if (nleft != 0) {
  62                 while (--nleft != 0) {
  63                         if ((*dst++ = *src++) == L'\0')
  64                                 break;
  65                 }
  66         }
  67
  68         /* Not enough room in dst, add NUL and traverse rest of src. */
  69         if (nleft == 0) {
  70                 if (dsize != 0)
  71                         *dst = L'\0';           /* NUL-terminate dst */
  72                 while (*src++)
  73                         ;
  74         }
  75
  76         return(src - osrc - 1); /* count does not include NUL */
  77 }