Check Access Permissions (continued.)

  /* scan all directories in the path and check each of them. */
  p_slash = file_path;
  while ( (p_slash = strchr(p_slash, '/')) != NULL) {
    /* copy directory path (including trailing slash) */
    /* into dir_path. */
    strncpy(dir_path, file_path, p_slash-file_path+1);
    dir_path[p_slash-file_path+1] = '\0';

    /* check existance and X permission for this directory. */
    if (access(dir_path, F_OK) == -1) {
      sprintf(err_msg,
              "Directory '%s' in the path does not exist.",
              dir_path);
      return 0;
    }
    if (access(dir_path, X_OK) == -1) {
      sprintf(err_msg,
              "Directory '%s' in the path - no 'X' permission.",
              dir_path);
      return 0;
    }
    /* skip the current slash, so the next strchr() call will */
    /* find the next slash in the file path.                  */
    p_slash++;
  }