如何把这里的图片抓取到本地

$str = '';
$fp = fopen('http://www.bocobo.com/PUBLIC_PAGES/show_img.jsp?book_id=177', 'r');
while($tmpStr=fread($fp, 1024))
$str .= $tmpStr;
fclose($fp);

$fp = fopen('http://www.pushad.com/Info/AA.GIF', 'w');
fwrite($fp, $str);
fclose($fp);

echo '';
?>