 from <code>l_start</code> which is relative to <code>l_whence</code>.</td>
</tr>
<tr class="odd">
<td style="text-align: center;"><code>l_pid</code></td>
<td>The process ID of the process holding the lock. This is set by the kernel when using the F_RDLCK command.</td>
</tr>
</tbody>
</table>
<p>In our example, we told it make a lock of type <code>F_WRLCK</code> (a write lock), starting relative to <code>SEEK_SET</code> (the beginning of the file), offset <code>0</code>, length <code>0</code> (a zero value 