Modify image file name parameters

Find a parameter to modify the image file name. find a CURL to save the remote image to the local server. the following code is a CURL to get the image and save the image parameters. The younger brother is not familiar with php. The answer to this question is, for example, "tp?@fopen('123.jpg', 'a}}calculate a parameter for modifying the image file name in this 123.jpg file.
Find a CURL to save the remote image to the local server.
The following code uses a CURL to obtain the image and save the image parameters. The younger brother is not familiar with php.
The problem to be solved now is how to $ tp = @fopen('123.jpg ', 'a); change this 123.jpg parameter to a file named after time
$ Url = 'http: // app.qlogo.cn/mbloghead/6e033128b37c1223af52/180.jpg ';
$ Curl = curl_init ($ url );
$ M = date ('y, m, dday', time () + (60*60*8 ));
Curl_setopt ($ curl, CURLOPT_REFERER, 'http: // app.qlogo.cn ');
Curl_setopt ($ curl, CURLOPT_RETURNTRANSFER, 1 );
// Whether the content is displayed
$ ImageData = curl_exec ($ curl); curl_close ($ curl );
// Save the image
$ Tp = @fopen('123.jpg ', 'a );
Fwrite ($ tp, $ imageData );
Fclose ($ tp );
?>

------ Solution --------------------
$ Url = 'http: // app.qlogo.cn/mbloghead/6e033128b37c1223af52/180.jpg ';
$ Curl = curl_init ($ url );
$ M = date ('ymdhis '). ". jpg ";
Curl_setopt ($ curl, CURLOPT_REFERER, 'http: // app.qlogo.cn ');
Curl_setopt ($ curl, CURLOPT_RETURNTRANSFER, 1 );
// Whether the content is displayed
$ ImageData = curl_exec ($ curl); curl_close ($ curl );
// Save the image
$ Tp = @ fopen ($ m, 'A ');
Fwrite ($ tp, $ imageData );
Fclose ($ tp );
?>