ction parameters, and to perform extra error checks on the
arguments and results. For instance, the Unix <span class=machine><span class=font-tt>write</span></span> system call can
be specified in IDL as follows:
</p><pre>        int write([in] int fd,
                  [in,string,length_is(len)] char * data,
                  [in] int len,
                  [in] int ofs,
                  [in] int towrite)
          quote(call,
            " /* Validate the arguments */
              if (ofs &lt; 0 || ofs 