how to get the image by curl query in php

1function grab_image($url,$saveto){
2    $ch = curl_init ($url);
3    curl_setopt($ch, CURLOPT_HEADER, 0);
4    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
5    curl_setopt($ch, CURLOPT_BINARYTRANSFER,1);
6    $raw=curl_exec($ch);
7    curl_close ($ch);
8    if(file_exists($saveto)){
9        unlink($saveto);
10    }
11    $fp = fopen($saveto,'x');
12    fwrite($fp, $raw);
13    fclose($fp);
14}