PHPのリモート画像のダウンロード

    /**
     *       
     * @param string $url      url
     * @param string $filepath        （  /www/images/test） ，          url http           
     * @param string $filename        (     )
     * @return mixed                  ，       false
     */
    public function downloadImage($url, $filepath, $filename)
    {
        //         
        $responseHeaders = array();
        //     
        $originalfilename = '';
        //      
        $ext = '';
        $ch = curl_init($url);
        //  curl_exec      Http 
        curl_setopt($ch, CURLOPT_HEADER, 1);
        //  curl_exec      Http  
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        //      （http 301，302）    
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
        //     HTTP      
        curl_setopt($ch, CURLOPT_MAXREDIRS, 3);

        //        （  http      ）
        $html = curl_exec($ch);
        //           
        $httpinfo = curl_getinfo($ch);
        curl_close($ch);
        if ($html !== false) {
            //  response header body，          302  ，              2+        
            $httpArr = explode("\r
\r
", $html, 2 + $httpinfo['redirect_count']);
            //             response http 
            $header = $httpArr[count($httpArr) - 2];
            //             response   
            $body = $httpArr[count($httpArr) - 1];
            $header .= "\r
";

            //      response header  
            preg_match_all('/([a-z0-9-_]+):\s*([^\r
]+)\r
/i', $header, $matches);
            if (!empty($matches) && count($matches) == 3 && !empty($matches[1]) && !empty($matches[1])) {
                for ($i = 0; $i < count($matches[1]); $i++) {
                    if (array_key_exists($i, $matches[2])) {
                        $responseHeaders[$matches[1][$i]] = $matches[2][$i];
                    }
                }
            }
            //       
            if (0 < preg_match('{(?:[^\/\\\\]+)\.(jpg|jpeg|gif|png|bmp)$}i', $url, $matches)) {
                $originalfilename = $matches[0];
                $ext = $matches[1];
            } else {
                if (array_key_exists('Content-Type', $responseHeaders)) {
                    if (0 < preg_match('{image/(\w+)}i', $responseHeaders['Content-Type'], $extmatches)) {
                        $ext = $extmatches[1];
                    }
                }
            }
            //    
            if (!empty($ext)) {
                //       ，       
                if (!is_dir($filepath)) {
                    mkdir($filepath, 0777, true);
                }

                $filepath .= '/' . $filename . ".$ext";
                $local_file = fopen($filepath, 'w');
                if (false !== $local_file) {
                    if (false !== fwrite($local_file, $body)) {
                        fclose($local_file);
                        $sizeinfo = getimagesize($filepath);
//                        return array('filepath' => realpath($filepath), 'width' => $sizeinfo[0], 'height' => $sizeinfo[1], 'orginalfilename' => $originalfilename, 'filename' => pathinfo($filepath, PATHINFO_BASENAME));
                        return array('orginalfilename' => $originalfilename, 'filename' => pathinfo($filepath, PATHINFO_BASENAME));
                    }
                }
            }
        }
        return false;
    }