Размер удаленного файла

    protected function curl_get_file_size( $url ) {
        $result = -1;
        $curl = curl_init( $url );
        curl_setopt( $curl, CURLOPT_NOBODY, true );
        curl_setopt( $curl, CURLOPT_HEADER, true );
        curl_setopt( $curl, CURLOPT_RETURNTRANSFER, true );
        curl_setopt( $curl, CURLOPT_FOLLOWLOCATION, true );
        $data = curl_exec( $curl );
        curl_close( $curl );

        if( $data ) {
            $content_length = "unknown";
            $status = "unknown";
            if( preg_match( "/^HTTP\/1\.[01] (\d\d\d)/", $data, $matches ) ) {
                $status = (int)$matches[1];
            }
            if( preg_match( "/Content-Length: (\d+)/", $data, $matches ) ) {
                $content_length = (int)$matches[1];
            }
            if( $status == 200 || ($status > 300 && $status <= 308) ) {
                $result = $content_length/1000/1000;
            }
        }
        return $result;
    }

var_dump($this->curl_get_file_size($img_url));