elseif($act == "renameFolder"){
    //echo $dirname;
    //完成文件夹重命名
    $str = <<<EOF
    <form action="index.php?act=doRenameFolder" method="post">
    请填写新文件夹名：<input type="text" name="newname" placeholder="重命名文件夹"/><br />
    <input type="hidden" name="path" value="$path"/>
    <input type="hidden" name="dirname" value="{$dirname}"/>
    <input type="submit" value="重命名文件夹"/>
    </form>
EOF;
    echo $str;
}elseif($act == "doRenameFolder"){
    $newname = $_REQUEST['newname'];
    $mes = renameFolder($dirname,$path."/".$newname);
    //alertMes($mes,$redirect);
}
---------------------------------------------
<tr>
<td><?php echo $i;?></td>
<td><?php echo $val;?></td>
<td><?php $src=filetype($p)=="file"?"file_ico.png":"folder_ico.png";?><img src="images/<?php echo $src;?>" alt="" title="folder"/></td>
<!-- <td><?php $sum = 0; echo transByte(dirSize($p));?></td> -->
<td><?php $src=is_readable($p) ? "correct.png":"error.png";?><img src="images/<?php echo $src;?>" alt=""/></td>
<td><?php $src=is_writable($p) ? "correct.png":"error.png";?><img src="images/<?php echo $src;?>" alt=""/></td>
<td><?php $src=is_executable($p) ? "correct.png":"error.png";?><img src="images/<?php echo $src;?>" alt=""/></td>
<td><?php echo date('Y-m-d H:i:s',filectime($p));?></td>
<td><?php echo date('Y-m-d H:i:s',filemtime($p));?></td>
<td><?php echo date('Y-m-d H:i:s',fileatime($p));?></td>
<td>
    <a href="index.php?path=<?php echo $p;?>"><img class="small" src="images/show.png" alt="" title="查看"/></a>
    <a href="index.php?act=renameFolder&path=<?php echo $path;?>&dirname=<?php echo $p;?>"><img class="small" src="images/rename.png" alt="" title="重命名"/></a>
    <a href="index.php?act=copyFolder&path=<?php echo $path;?>&dirname=<?php echo $p;?>"><img class="small" src="images/copy.png" alt="" title="复制"/></a>
    <a href="index.php?act=cutFolder&path=<?php echo $path;?>&dirname=<?php echo $p;?>"><img class="small" src="images/cut.png" alt="" title="剪切"/></a>
    <a href="#" onclick="delFile('<?php echo $p;?>')"><img class="small" src="images/delete.png" alt="" title="删除"/></a>
</td>
</tr>
---------------------------------------------
function renameFolder($oldname,$newname){
    //检测文件夹名称的合法性
    if(checkFilename(basename($newname))){
        //检测当前目录下是否存在同名文件夹
        if(!file_exists($newname)){
            if(rename($oldname,$newname)){
                $mes = "重命名成功";
            }else{
                $mes = "重命名失败";
            }
        }else{
            $mes = "存在同名文件夹";
        }
    }else{
        $mes = "非法文件夹名称";
    }
    return $mes;
}

即使是把

<!-- <td><?php $sum = 0; echo transByte(dirSize($p));?></td> -->

这条代码注释掉，也还是没有解决