PHP中调用PERL获取网叶内容

$urllist = 'http://www.searchpixie.com/xmlsearch.php?keywords=web%20hosting&startat_xml=1&adult_filter=0&pageresult=20&username=fs888&ip_address=121.204.134.172 ';
$urlname = 'searchpixie.com';
$perldata = shell_exec( "perl loader.cgi " .$urlname." {$urllist} " );
echo $perldata;我想获得$urlist网址中的xml内容,$perldata = shell_exec( "perl loader.cgi " .$urlname." {$urllist} " );
这句应该怎么写呢? 在线等待.......