生成ubuntu自动切换壁纸xml文件的php代码

<?php
/*
* 生成ubuntu自动切换壁纸xml文件
*/
//图片目录
$dir = /home/yuxing/background;

$hd = opendir($dir) or die(can not open dir);
$files = array();
while($file = readdir($hd)) {
$tem = "$dir/$file";
if (is_file($tem) && in_array(strtolower(substr(strrchr($file,.), 1)), array(jpg, gif)))
$files[] = $tem;
}
closedir($hd);
unset($file);

$xw = new xmlWriter();
$xw->openMemory();
$xw->setIndent(true);
$xw->setIndentString( );
$xw->startDocument(1.0, utf-8);
$xw->startElement(background);
$xw->startElement(starttime);
$xw->writeElement(year, 2000);
$xw->writeElement(month, 01);
$xw->writeElement(day, 01);
$xw->writeElement(hour, 00);
$xw->writeElement(minute, 00);
$xw->writeElement(second, 00);
$xw->endElement();
$count = count($files);
for ($i=0; $i<$count; $i++) {
$xw->startElement(static);
//$xw->writeElement(duration, 1795.0);
$xw->writeElement(duration, 30.0);
$xw->writeElement(file, $files[$i]);
$xw->endElement();
$xw->startElement(transition);
$xw->writeElement(duration, 5);
$xw->writeElement(from, $files[$i]);
$xw->writeElement(to, isset($files[$i+1]) ? $files[$i+1] : $files[0]);
$xw->endElement();
}
$xw->endElement();
$xml = $xw->outputMemory(true);
//生成文件
$hd = fopen($dir . "/yuxing.xml", wb);
fwrite($hd, $xml);
fclose($hd);
echo ok;
?>