php如何发送与接收流文件

<?php 
/** php 发送流文件 
* @param String $url 接收的路径 
* @param String $file 要发送的文件 
* @return boolean 
*/ 
function sendStreamFile($url, $file){ 
  if(file_exists($file)){ 
    $opts = array( 
      'http' => array( 
        'method' => 'POST', 
        'header' => 'content-type:application/x-www-form-urlencoded', 
        'content' => file_get_contents($file) 
      ) 
    ); 
    $context = stream_context_create($opts); 
    $response = file_get_contents($url, false, $context); 
    $ret = json_decode($response, true); 
    return $ret['success']; 
  }else{ 
    return false; 
  } 
} 
$ret = sendStreamFile('http://localhost/receiveStreamFile.php','send.txt');
var_dump($ret); 
?>

]<?php 
/** php 接收流文件 
* @param String $file 接收后保存的文件名 
* @return boolean 
*/ 
function receiveStreamFile($receiveFile){ 
  $streamData = isset($GLOBALS['HTTP_RAW_POST_DATA'])? $GLOBALS['HTTP_RAW_POST_DATA'] : ''; 
 
  if(empty($streamData)){ 
    $streamData = file_get_contents('php://input'); 
  } 
 
  if($streamData!=''){ 
    $ret = file_put_contents($receiveFile, $streamData, true);
  }else{ 
    $ret = false; 
  } 
  return $ret; 
} 
$receiveFile = 'receive.txt'; 
$ret = receiveStreamFile($receiveFile); 
echo json_encode(array('success'=>(bool)$ret)); 
?>

$filepath = 'http://www.vip.com/down';
$fp = fopen($filepath,"r");
Header("Content-type: application/octet-stream");
Header("Accept-Ranges: bytes");
Header("Content-Disposition: attachment; filename=xxx.pdf");
$buffer = 1024;
while (!feof($fp)) {
$file_con = fread($fp,$buffer);
  echo $file_con;
}
fclose($fp);