StdLib/LibC/String/strlcpy.c

   1 /*  $NetBSD: strlcpy.c,v 1.3 2007/06/04 18:19:27 christos Exp $ */
   2 /*  $OpenBSD: strlcpy.c,v 1.7 2003/04/12 21:56:39 millert Exp $ */
   3
   4 /*
   5  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
   6  *
   7  * Permission to use, copy, modify, and distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND TODD C. MILLER DISCLAIMS ALL
  12  * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  13  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL TODD C. MILLER BE LIABLE
  14  * FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
  16  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  17  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  */
  19 #include  <LibConfig.h>
  20
  21 #if !defined(_KERNEL) && !defined(_STANDALONE)
  22 #if HAVE_NBTOOL_CONFIG_H
  23 #include "nbtool_config.h"
  24 #endif
  25
  26 #include <sys/cdefs.h>
  27 #if defined(LIBC_SCCS) && !defined(lint)
  28 __RCSID("$NetBSD: strlcpy.c,v 1.3 2007/06/04 18:19:27 christos Exp $");
  29 #endif /* LIBC_SCCS and not lint */
  30
  31 #ifdef _LIBC
  32 #include "namespace.h"
  33 #endif
  34 #include <sys/types.h>
  35 #include <assert.h>
  36 #include <string.h>
  37
  38 #ifdef _LIBC
  39 # ifdef __weak_alias
  40 __weak_alias(strlcpy, _strlcpy)
  41 # endif
  42 #endif
  43 #else
  44 #include <lib/libkern/libkern.h>
  45 #endif /* !_KERNEL && !_STANDALONE */
  46
  47
  48 #if !HAVE_STRLCPY
  49 /*
  50  * Copy src to string dst of size siz.  At most siz-1 characters
  51  * will be copied.  Always NUL terminates (unless siz == 0).
  52  * Returns strlen(src); if retval >= siz, truncation occurred.
  53  */
  54 size_t
  55 strlcpy(char *dst, const char *src, size_t siz)
  56 {
  57   char *d = dst;
  58   const char *s = src;
  59   size_t n = siz;
  60
  61   _DIAGASSERT(dst != NULL);
  62   _DIAGASSERT(src != NULL);
  63
  64   /* Copy as many bytes as will fit */
  65   if (n != 0 && --n != 0) {
  66     do {
  67       if ((*d++ = *s++) == 0)
  68         break;
  69     } while (--n != 0);
  70   }
  71
  72   /* Not enough room in dst, add NUL and traverse rest of src */
  73   if (n == 0) {
  74     if (siz != 0)
  75       *d = '\0';    /* NUL-terminate dst */
  76     while (*s++)
  77       ;
  78   }
  79
  80   return(s - src - 1);  /* count does not include NUL */
  81 }
  82 #endif