我只能在tr需要帮助修复代码之间抓取第一组文本

<?php
$tagname = "tr";    
$doc = file_get_contents("test.html"); 
$pattern = "/<$tagname>(.*?)<\/$tagname>/";
preg_match_all($pattern, $doc, $matches);
foreach ($matches as $match) {
    echo ++$xx; //counts up every match
    echo " -- ";
    echo $match;
    echo "\n\r";
}
?>
<?php
$tagname = "tr";    
$doc = file_get_cont