openbsd-compat/strlcpy.c

   1 /*      $OpenBSD: strlcpy.c,v 1.10 2005/08/08 08:05:37 espie 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 /* OPENBSD ORIGINAL: lib/libc/string/strlcpy.c */
  20
  21 #include "includes.h"
  22 #ifndef HAVE_STRLCPY
  23
  24 #include <sys/types.h>
  25 #include <string.h>
  26
  27 /*
  28  * Copy src to string dst of size siz.  At most siz-1 characters
  29  * will be copied.  Always NUL terminates (unless siz == 0).
  30  * Returns strlen(src); if retval >= siz, truncation occurred.
  31  */
  32 size_t
  33 strlcpy(char *dst, const char *src, size_t siz)
  34 {
  35         char *d = dst;
  36         const char *s = src;
  37         size_t n = siz;
  38
  39         /* Copy as many bytes as will fit */
  40         if (n != 0 && --n != 0) {
  41                 do {
  42                         if ((*d++ = *s++) == 0)
  43                                 break;
  44                 } while (--n != 0);
  45         }
  46
  47         /* Not enough room in dst, add NUL and traverse rest of src */
  48         if (n == 0) {
  49                 if (siz != 0)
  50                         *d = '\0';              /* NUL-terminate dst */
  51                 while (*s++)
  52                         ;
  53         }
  54
  55         return(s - src - 1);    /* count does not include NUL */
  56 }
  57
  58 #endif /* !HAVE_STRLCPY */