define read_file (file)
    {
       variable buf, fp, root, tail;
       variable list_type = struct { text, next };

       root = NULL;

       fp = fopen(file, "r");
       if (fp == NULL)
         error("fopen %s failed." file);
       while (-1 != fgets (&buf, fp))
         {
            if (root == NULL)
              {
                 root = @list_type;
                 tail = root;
              }
            else
              {
                 tail.next = @list_type;
                 tail = tail.next;
              }
            tail.text = buf;
            tail.next = NULL;
         }
       () = fclose (fp);
       return root;
    }