src/system/libroot/posix/string/strlcat.c

   1 /*
   2 ** Copyright 2002, Manuel J. Petit. All rights reserved.
   3 ** Distributed under the terms of the NewOS License.
   4 */
   5
   6 #include <sys/types.h>
   7 #include <string.h>
   8
   9
  10 /** Concatenates the source string to the destination, writes
  11  *      as much as "maxLength" bytes to the dest string.
  12  *      Always null terminates the string as long as maxLength is
  13  *      larger than the dest string.
  14  *      Returns the length of the string that it tried to create
  15  *      to be able to easily detect string truncation.
  16  */
  17
  18 size_t
  19 strlcat(char *dest, const char *source, size_t maxLength)
  20 {
  21         size_t destLength = strnlen(dest, maxLength), i;
  22
  23         // This returns the wrong size, but it's all we can do
  24         if (maxLength == destLength)
  25                 return destLength + strlen(source);
  26
  27         dest += destLength;
  28         maxLength -= destLength;
  29
  30         for (i = 0; i < maxLength - 1 && source[i]; i++) {
  31                 dest[i] = source[i];
  32         }
  33
  34         dest[i] = '\0';
  35
  36         return destLength + i + strlen(source + i);
  37 }
  38