p;&nbsp;&nbsp;&nbsp;<span class="constructor">Unix</span>.open_flag&nbsp;=<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="constructor">O_RDONLY</span><br>
&nbsp;&nbsp;&nbsp;&nbsp;<span class="keywordsign">|</span>&nbsp;<span class="constructor">O_WRONLY</span><br>
&nbsp;&nbsp;&nbsp;&nbsp;<span class="keywordsign">|</span>&nbsp;<span class="constructor">O_RDWR</span><br>
&nbsp;&nbsp;&nbsp;&nbsp;<span class="keywordsign">|</span>&nbsp;<span class="constructor">O_NONBLOCK</span><br>
&nbsp;&nbsp;&nbsp;&nb