contrib/ldns/compat/strlcpy.c

   1 /* from openssh 4.3p2 compat/strlcpy.c */
   2 /*
   3  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* OPENBSD ORIGINAL: lib/libc/string/strlcpy.c */
  19
  20 #include <ldns/config.h>
  21 #ifndef HAVE_STRLCPY
  22
  23 #include <sys/types.h>
  24 #include <string.h>
  25
  26 /*
  27  * Copy src to string dst of size siz.  At most siz-1 characters
  28  * will be copied.  Always NUL terminates (unless siz == 0).
  29  * Returns strlen(src); if retval >= siz, truncation occurred.
  30  */
  31 size_t
  32 strlcpy(char *dst, const char *src, size_t siz)
  33 {
  34         char *d = dst;
  35         const char *s = src;
  36         size_t n = siz;
  37
  38         /* Copy as many bytes as will fit */
  39         if (n != 0 && --n != 0) {
  40                 do {
  41                         if ((*d++ = *s++) == 0)
  42                                 break;
  43                 } while (--n != 0);
  44         }
  45
  46         /* Not enough room in dst, add NUL and traverse rest of src */
  47         if (n == 0) {
  48                 if (siz != 0)
  49                         *d = '\0';              /* NUL-terminate dst */
  50                 while (*s++)
  51                         ;
  52         }
  53
  54         return(s - src - 1);    /* count does not include NUL */
  55 }
  56
  57 #endif /* !HAVE_STRLCPY */