php 采集远程图片(可采集防盗链)

function grabimage($url,$filename="") {
  if($url==""):return false;endif;

  if($filename=="") {
    $ext=strrchr($url,".");
    if($ext!=".gif" && $ext!=".jpg"):return false;endif;
    $filename=date("dmyhis").$ext;
  }

  ob_start();
  readfile($url);
  $img = ob_get_contents();
  ob_end_clean();
  $size = strlen($img);

  $fp2=@fopen($filename, "a");
  fwrite($fp2,$img);
  fclose($fp2);

  return $filename;
}

$ch = curl_init();
curl_setopt($ch, curlopt_url, $url);//这是目标地址
curl_setopt($ch, curlopt_header, 0);
curl_setopt($ch, curlopt_returntransfer, 1);
curl_setopt($ch, curlopt_referer,   $referer);//这里伪造
$data = curl_exec($ch);
curl_close($ch);
echo $data;