PHP重复打印语句

我遇到了一个PHP打印语句的问题，该语句连续重复输出大约40或50次，然后停止。我以为它应该只打印一行。我对PHP还是有点陌生，所以我不明白我做错了什么。有问题的代码位于代码段的底部。

提前感谢。。。。。

 <?php
$query = $_POST['query'];
find_files('.');
function find_files($seed) {
    if(! is_dir($seed)) return false;
    $files = array();
    $dirs = array($seed);
    while(NULL !== ($dir = array_pop($dirs))) {
        if($dh = opendir($dir)) {
            while( false !== ($file = readdir($dh))) {
                if($file == '.' || $file == '..') continue;
                $path = $dir . '/' . $file;
                if(is_dir($path)) { 
                    $dirs[] = $path; 
                } else { 
                    if(preg_match('/^.*'.(php['d]?|js|txt)$/i', $path)) { 
                        check_files($path); 
                    }
                }
            }
            closedir($dh);
        }
    }
}
function check_files($this_file) {
    $query = $_POST['query'];
    $str_to_find = $query;
    if ((isset($str_to_find)) && (empty($str_to_find))) {
        print '<p>Your search produced no results</p>';
    } else {
        if(!($content = file_get_contents($this_file))) { 
            echo("<p>Could not check $this_file</p>'n"); 
        } else { 
            if(stristr($content, $str_to_find)) { 
                echo("<p>$this_file -> contains $str_to_find</p>'n"); 
            }
        }
        unset($content);
    }
}
?>