compat.c

   1 /*      $OpenBSD: strlcat.c,v 1.13 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 #ifdef HAVE_CONFIG_H
  19 #include "config.h"
  20 #endif
  21
  22 #include <sys/types.h>
  23 #include <string.h>
  24
  25 int dummy; /* To prevent an empty object file */
  26
  27 #ifndef HAVE_STRLCAT
  28 /*
  29  * Appends src to string dst of size siz (unlike strncat, siz is the
  30  * full size of dst, not space left).  At most siz-1 characters
  31  * will be copied.  Always NUL terminates (unless siz <= strlen(dst)).
  32  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
  33  * If retval >= siz, truncation occurred.
  34  */
  35 size_t
  36 strlcat(char *dst, const char *src, size_t siz)
  37 {
  38         char *d = dst;
  39         const char *s = src;
  40         size_t n = siz;
  41         size_t dlen;
  42
  43         /* Find the end of dst and adjust bytes left but don't go past end */
  44         while (n-- != 0 && *d != '\0')
  45                 d++;
  46         dlen = d - dst;
  47         n = siz - dlen;
  48
  49         if (n == 0)
  50                 return(dlen + strlen(s));
  51         while (*s != '\0') {
  52                 if (n != 1) {
  53                         *d++ = *s;
  54                         n--;
  55                 }
  56                 s++;
  57         }
  58         *d = '\0';
  59
  60         return(dlen + (s - src));       /* count does not include NUL */
  61 }
  62 #endif
  63
  64 #ifndef HAVE_STRLCPY
  65 /*
  66  * Copy src to string dst of size siz.  At most siz-1 characters
  67  * will be copied.  Always NUL terminates (unless siz == 0).
  68  * Returns strlen(src); if retval >= siz, truncation occurred.
  69  */
  70 size_t
  71 strlcpy(char *dst, const char *src, size_t siz)
  72 {
  73         char *d = dst;
  74         const char *s = src;
  75         size_t n = siz;
  76
  77         /* Copy as many bytes as will fit */
  78         if (n != 0) {
  79                 while (--n != 0) {
  80                         if ((*d++ = *s++) == '\0')
  81                                 break;
  82                 }
  83         }
  84
  85         /* Not enough room in dst, add NUL and traverse rest of src */
  86         if (n == 0) {
  87                 if (siz != 0)
  88                         *d = '\0';              /* NUL-terminate dst */
  89                 while (*s++)
  90                         ;
  91         }
  92
  93         return(s - src - 1);    /* count does not include NUL */
  94 }
  95 #endif