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 <stdio.h>
  23   #include <string.h>
  24  #endif /* !STRLCAT_INCLUDE_LIBC */
  25
  26  #ifndef HAVE_STRLCAT
  27   #define HAVE_STRLCAT  1
  28   #define strlcat       i_strlcat_
  29   #define strlcpy       i_strlcpy_
  30 size_t i_strlcat_(char *dst, const char *src, size_t siz);
  31 size_t i_strlcpy_(char *dst, const char *src, size_t siz);
  32  #endif /* !HAVE_STRLCAT */
  33
  34  #ifdef STRLCAT_IMPLEMENTATION
  35 /*
  36  * Appends src to string dst of size siz (unlike strncat, siz is the
  37  * full size of dst, not space left). At most siz-1 characters
  38  * will be copied. Always NUL terminates (unless siz <= strlen(dst)).
  39  * Returns strlen(src) + MIN(siz, strlen(initial dst)).
  40  * If retval >= siz, truncation occurred.
  41  */
  42 size_t
  43 i_strlcat_(char *dst, const char *src, size_t siz)
  44 {
  45         char *d = dst;
  46         const char *s = src;
  47         size_t n = siz;
  48         size_t dlen;
  49         /* Find the end of dst and adjust bytes left but don't go past end */
  50         while (n-- != 0 && *d != '\0')
  51                 d++;
  52         dlen = d - dst;
  53         n = siz - dlen;
  54         if (n == 0)
  55                 return (dlen + strlen(s));
  56         while (*s != '\0') {
  57                 if (n != 1) {
  58                         *d++ = *s;
  59                         n--;
  60                 }
  61                 s++;
  62         }
  63         *d = '\0';
  64         return (dlen + (s - src)); /* count does not include NUL */
  65 }
  66
  67 /*
  68  * Copy src to string dst of size siz. At most siz-1 characters
  69  * will be copied. Always NUL terminates (unless siz == 0).
  70  * Returns strlen(src); if retval >= siz, truncation occurred.
  71  */
  72 size_t
  73 i_strlcpy_(char *dst, const char *src, size_t siz)
  74 {
  75         char *d = dst;
  76         const char *s = src;
  77         size_t n = siz;
  78         /* Copy as many bytes as will fit */
  79         if (n != 0) {
  80                 while (--n != 0) {
  81                         if ((*d++ = *s++) == '\0')
  82                                 break;
  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         return(s - src - 1); /* count does not include NUL */
  93 }
  94  #endif /* STRLCAT_IMPLEMENTATION */
  95 #endif /* !STRLCAT_H_ */