compiler/stdc/strlcpy.c

   1 /*      $OpenBSD: strlcpy.c,v 1.5 2001/05/13 15:40:16 deraadt Exp $     */
   2
   3 /*
   4  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. The name of the author may not be used to endorse or promote products
  16  *    derived from this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
  19  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
  20  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
  21  * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  22  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  23  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
  24  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  25  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  26  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  27  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char *rcsid = "$OpenBSD: strlcpy.c,v 1.5 2001/05/13 15:40:16 deraadt Exp $";
  32 #endif /* LIBC_SCCS and not lint */
  33
  34 #include <stddef.h>
  35 #include <string.h>
  36
  37 /*
  38  * Copy src to string dst of size siz.  At most siz-1 characters
  39  * will be copied.  Always NUL terminates (unless siz == 0).
  40  * Returns strlen(src); if retval >= siz, truncation occurred.
  41  */
  42
  43 /*****************************************************************************
  44
  45     NAME */
  46
  47         size_t strlcpy(
  48
  49 /*  SYNOPSIS */
  50         char *dst,
  51         const char *src,
  52         size_t siz)
  53
  54 /*  FUNCTION
  55
  56     INPUTS
  57
  58     RESULT
  59
  60     NOTES
  61
  62     EXAMPLE
  63
  64     BUGS
  65
  66     SEE ALSO
  67
  68     INTERNALS
  69
  70 ******************************************************************************/
  71 {
  72         register char *d = dst;
  73         register const char *s = src;
  74         register size_t n = siz;
  75
  76         /* Copy as many bytes as will fit */
  77         if (n != 0 && --n != 0) {
  78                 do {
  79                         if ((*d++ = *s++) == 0)
  80                                 break;
  81                 } while (--n != 0);
  82         }
  83
  84         /* Not enough room in dst, add NUL and traverse rest of src */
  85         if (n == 0) {
  86                 if (siz != 0)
  87                         *d = '\0';              /* NUL-terminate dst */
  88                 while (*s++)
  89                         ;
  90         }
  91
  92         return(s - src - 1);    /* count does not include NUL */
  93 }
  94