lib/Support/regstrlcpy.c

   1 /*
   2  * This code is derived from OpenBSD's libc, original license follows:
   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 #include <sys/types.h>
  20 #include <string.h>
  21
  22 #include "regex_impl.h"
  23 /*
  24  * Copy src to string dst of size siz.  At most siz-1 characters
  25  * will be copied.  Always NUL terminates (unless siz == 0).
  26  * Returns strlen(src); if retval >= siz, truncation occurred.
  27  */
  28 size_t
  29 llvm_strlcpy(char *dst, const char *src, size_t siz)
  30 {
  31         char *d = dst;
  32         const char *s = src;
  33         size_t n = siz;
  34
  35         /* Copy as many bytes as will fit */
  36         if (n != 0) {
  37                 while (--n != 0) {
  38                         if ((*d++ = *s++) == '\0')
  39                                 break;
  40                 }
  41         }
  42
  43         /* Not enough room in dst, add NUL and traverse rest of src */
  44         if (n == 0) {
  45                 if (siz != 0)
  46                         *d = '\0';              /* NUL-terminate dst */
  47                 while (*s++)
  48                         ;
  49         }
  50
  51         return(s - src - 1);    /* count does not include NUL */
  52 }