strlcat.h

   1 /*
   2  * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 /* https://git.datadissipation.net */
  18 #ifndef STRLCAT_H_
  19  #define STRLCAT_H_     1
  20
  21  #ifdef STRLCAT_INCLUDE_LIBC
  22   #include <stddef.h>
  23   #include <stdio.h>
  24   #include <string.h>
  25  #endif /* !STRLCAT_INCLUDE_LIBC */
  26
  27  #ifndef HAVE_STRLCAT
  28   #define HAVE_STRLCAT  1
  29   #define strlcat       i_strlcat_
  30   #define strlcpy       i_strlcpy_
  31 size_t i_strlcat_(char *dst, const char *src, size_t siz);
  32 size_t i_strlcpy_(char *dst, const char *src, size_t siz);
  33  #endif /* !HAVE_STRLCAT */
  34
  35  #ifdef STRLCAT_IMPLEMENTATION
  36 /*
  37  * Appends src to string dst of size siz (unlike strncat, siz is the
  38  * full size of dst, not space left). At most siz-1 characters
  39  * will be copied. Always NUL terminates (unless siz <= strlen(dst)).
  40  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
  41  * If retval >= siz, truncation occurred.
  42  */
  43 size_t
  44 i_strlcat_(char *dst, const char *src, size_t siz)
  45 {
  46         char *d = dst;
  47         const char *s = src;
  48         size_t n = siz;
  49         size_t dlen;
  50         /* Find the end of dst and adjust bytes left but don't go past end */
  51         while (n-- != 0 && *d != '\0')
  52                 d++;
  53         dlen = d - dst;
  54         n = siz - dlen;
  55         if (n == 0)
  56                 return (dlen + strlen(s));
  57         while (*s != '\0') {
  58                 if (n != 1) {
  59                         *d++ = *s;
  60                         n--;
  61                 }
  62                 s++;
  63         }
  64         *d = '\0';
  65         return (dlen + (s - src)); /* count does not include NUL */
  66 }
  67
  68 /*
  69  * Copy src to string dst of size siz. At most siz-1 characters
  70  * will be copied. Always NUL terminates (unless siz == 0).
  71  * Returns strlen(src); if retval >= siz, truncation occurred.
  72  */
  73 size_t
  74 i_strlcpy_(char *dst, const char *src, size_t siz)
  75 {
  76         char *d = dst;
  77         const char *s = src;
  78         size_t n = siz;
  79         /* Copy as many bytes as will fit */
  80         if (n != 0) {
  81                 while (--n != 0) {
  82                         if ((*d++ = *s++) == '\0')
  83                                 break;
  84                 }
  85         }
  86         /* Not enough room in dst, add NUL and traverse rest of src */
  87         if (n == 0) {
  88                 if (siz != 0)
  89                         *d = '\0'; /* NUL-terminate dst */
  90                 while (*s++)
  91                         ;
  92         }
  93         return(s - src - 1); /* count does not include NUL */
  94 }
  95  #endif /* STRLCAT_IMPLEMENTATION */
  96 #endif /* !STRLCAT_H_ */