那位大侠给看看这段代码什么意思!

<?php echo get_channel(array('bid' => 104,'len' => 0), $this);?>
<?php unset($this->_sections['list_channel']);
$this->_sections['list_channel']['name'] = 'list_channel';
$this->_sections['list_channel']['loop'] = is_array($_loop=$this->_tpl_vars['list_channel']) ? count($_loop) : max(0, (int)$_loop); unset($_loop);
$this->_sections['list_channel']['show'] = true;
$this->_sections['list_channel']['max'] = $this->_sections['list_channel']['loop'];
$this->_sections['list_channel']['step'] = 1;
$this->_sections['list_channel']['start'] = $this->_sections['list_channel']['step'] > 0 ? 0 : $this->_sections['list_channel']['loop']-1;
if ($this->_sections['list_channel']['show']) {
$this->_sections['list_channel']['total'] = $this->_sections['list_channel']['loop'];
if ($this->_sections['list_channel']['total'] == 0)
$this->_sections['list_channel']['show'] = false;
} else
$this->_sections['list_channel']['total'] = 0;
if ($this->_sections['list_channel']['show']):
for ($this->_sections['list_channel']['index'] = $this->_sections['list_channel']['start'], $this->_sections['list_channel']['iteration'] = 1;
$this->_sections['list_channel']['iteration'] <= $this->_sections['list_channel']['total'];
$this->_sections['list_channel']['index'] += $this->_sections['list_channel']['step'], $this->_sections['list_channel']['iteration']++):
$this->_sections['list_channel']['rownum'] = $this->_sections['list_channel']['iteration'];
$this->_sections['list_channel']['index_prev'] = $this->_sections['list_channel']['index'] - $this->_sections['list_channel']['step'];
$this->_sections['list_channel']['index_next'] = $this->_sections['list_channel']['index'] + $this->_sections['list_channel']['step'];
$this->_sections['list_channel']['first'] = ($this->_sections['list_channel']['iteration'] == 1);
$this->_sections['list_channel']['last'] = ($this->_sections['list_channel']['iteration'] == $this->_sections['list_channel']['total']);
?>
<li><img src="../images/7_03.gif" width="9" height="7" style="padding-left:10px;" /><a href="<?php echo $this->_tpl_vars['list_channel'][$this->_sections['list_channel']['index']]['url']; ?>
" class="C_lan2"><font color="#245893"><?php echo $this->_tpl_vars['list_channel'][$this->_sections['list_channel']['index']]['title']; ?>
</font></a></li>
<?php endfor; endif; ?>