php代码实例强制下载文件代码例子 

$filename = $_GET['file']; //Get the fileid from the URL 
    // Query the file ID 
    $query = sprintf("SELECT * FROM tableName WHERE id = '%s'",mysql_real_escape_string($filename)); 
    $sql = mysql_query($query); 
    if(mysql_num_rows($sql) > 0){ 
    $row = mysql_fetch_array($sql); 
    // Set some headers 
    header("Pragma: public"); 
    header("Expires: 0"); 
    header("Cache-Control: must-revalidate, post-check=0, pre-check=0"); 
    header("Content-Type: application/force-download"); 
    header("Content-Type: application/octet-stream"); 
    header("Content-Type: application/download"); 
    header("Content-Disposition: attachment; filename=".basename($row['FileName']).";"); 
    header("Content-Transfer-Encoding: binary"); 
    header("Content-Length: ".filesize($row['FileName'])); 
     
    @readfile($row['FileName']); 
    exit(0); 
    }else{ 
    header("Location: /"); 
    exit; 
    }

php代码实例从网上下载文件代码例子 

set_time_limit(0); 
    // Supports all file types 
    // URL Here: 
    $url = 'http://somsite.com/some_video.flv'; 
    $pi = pathinfo($url); 
    $ext = $pi['extension']; 
    $name = $pi['filename']; 
     
    // create a new cURL resource 
    $ch = curl_init(); 
     
    // set URL and other appropriate options 
    curl_setopt($ch, CURLOPT_URL, $url); 
    curl_setopt($ch, CURLOPT_HEADER, false); 
    curl_setopt($ch, CURLOPT_BINARYTRANSFER, true); 
    curl_setopt($ch, CURLOPT_AUTOREFERER, true); 
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true); 
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); 
     
    // grab URL and pass it to the browser 
    $opt = curl_exec($ch); 
     
    // close cURL resource, and free up system resources 
    curl_close($ch); 
     
    $saveFile = $name.'.'.$ext; 
    if(preg_match("/[^0-9a-z._-]/i", $saveFile)) 
    $saveFile = md5(microtime(true)).'.'.$ext; 
     
    $handle = fopen($saveFile, 'wb'); 
    fwrite($handle, $opt); 
    fclose($handle);