PHP写XML文件

<?php
    $domain = "DOMAIN";
    $username = "USERNAME"; 
    $owner = "OWNER" ;
    $template = "TEMPLATE" ;
    $description = "DESCRIPTION" ;
    $topics = "TOPICS" ;
    $subject  = "SUBJECT" ;

    $xmlstr = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n
        <batchcommands>\n
    \n	</batchcommands>";

    $xml = new SimpleXMLElement($xmlstr);

    $create = $xml->addchild('create');
    $mailing_list = $create->addchild('mailing_list');
    $mailing_list->addAttribute('domain', ($domain));
    $mailing_list->addAttribute('username', ($username));

    $mailing_list->addChild('owner', $owner);
    $mailing_list->addChild('template', $template);
    $mailing_list->addChild('description', $description);
    $mailing_list->addChild('topics', $topics);
    $mailing_list->addChild('subject', $subject);

    $xml->asXML("C:/create.xml");

?>

生成文件内容：

<?xml version="1.0" encoding="UTF-8"?>
<batchcommands>
	<create>
		<mailing_list domain="DOMAIN" username="USERNAME">
			<owner>OWNER</owner>
			<template>TEMPLATE</template>
			<description>DESCRIPTION</description>
			<topics>TOPICS</topics>
			<subject>SUBJECT</subject>
		</mailing_list>
	</create>
</batchcommands>