A piece of php code to detect whether the remote file exists

/**
 php detects whether the remote file exists
 by http://bbs.it-home.org
*/
function get_http_response_code($theURL) {
 $headers = get_headers($theURL);
 return substr($headers[0] , 9, 3);
}
/**
 * Fetches all the real headers sent by the server in response to a HTTP request without redirects
 * Gets the headers without redirects
*/
function get_real_headers($url,$format=0,$follow_redirect=0) {
 if (!$follow_redirect ) {
 //set new default options
 $opts = array('http' =>
 array('max_redirects'=>1,'ignore_errors'=>1)
 );
 stream_context_get_default($opts);
 }
 //get headers
 $headers=get_headers($url,$format);
 //restore default options
 if (isset($opts)) {
 $opts = array('http' =>
 array ('max_redirects'=>20,'ignore_errors'=>0)
 );
 stream_context_get_default($opts);
 }
 //return
 return $headers;
}
?>

For curl judgment method, please refer to: php code for using curl to judge whether a remote file exists .