php文件下载头文件

Question

这让我卡了很长时间，经过大量研究，我尝试了几种方法。

这是我当前下载文件的代码：

<?php
  require_once ('./newpub_profile.php');
  $thetitle = $row['title'];
  $thesize = $row['size'];

 function filedownload() { 
    GLOBAL $thesize, $thetitle;
    header("Content-Type: application/msword");
    header("Content-Disposition: attachment; filename=".$thetitle);
    header("Content-Length: ".$thesize);
    header("Content-Transfer-Encoding: binary");
    readfile($realfile);
 }
?>

在另一个 php 页面上，我正在填充一个查询结果表，每个结果都有一个相应的下载链接。如果我将鼠标悬停在链接上，我可以验证其下载 ID 是否正确（在 mysql db 中）。下载链接当前指向包含上述代码的 download.php。此代码允许我下载一个标题为“download.php”的文件，其中不包含任何内容。我从用户个人资料页面调用函数“filedownload()”。

这是我显示下载链接的方式：

while ($row = mysqli_fetch_array($r,MYSQLI_ASSOC))
        {
            echo '<tr><td align="left">' .
            $row['title'] . '</td><td align="left">'
            . $row['genre'] . '</td><td align="left">'
            . $row['length'] . '</td><td align="left">'
            . $row['created'] . '</td><td align="left">'
            //. $row['views'] . '</td><td align="left">'
            . "<a href='download.php?id={$row['upload_id']}'>Download</a></td>" . '</td></tr>';
        }

下面是调用 header 函数的页面代码。

    <?php if (isset($_POST['query']))
   {
   require_once (connectionToDB); //Connect to the db

    // Make the query
   $genre = $_POST['select_genre'];
   $length = $_POST['select_length'];

    $upviews = "UPDATE upload
                SET views = views + 1
                WHERE genre = '$genre' AND length = '$length'";
    $runviewupdate = mysqli_query ($dbc, $upviews);


    $q = "SELECT upload_id, title, genre, length, created
        FROM upload
        WHERE genre = '$genre' AND length = '$length'
        ORDER BY created DESC, title DESC";


    $r = mysqli_query ($dbc, $q); // Run the query

    if($r)
    {
        // If it ran okay, display the records
        echo '<table align="center"
            cellspacing="3" cellpadding="3"
            width="75%">
           <tr><td align="left"><b>Title</b></td>
           <td align="left"><b>Genre</b></td>
           <td align="left"><b>Pages</b></td>
           <td align="left"><b>Submitted</b></td>
           <td align="left"><b>Download</b></td>';

        // Fetch and print all the records:

        while ($row = mysqli_fetch_array($r,MYSQLI_ASSOC))
        {
            echo '<tr><td align="left">' .
            $row['title'] . '</td><td align="left">'
            . $row['genre'] . '</td><td align="left">'
            . $row['length'] . '</td><td align="left">'
            . $row['created'] . '</td><td align="left">'
            //. $row['views'] . '</td><td align="left">'
            . "<a href='newpub_profile.php?id={$row['upload_id']}'>Download</a></td>" . '</td></tr>';
        }
        echo '</table>'; // Close the table

        mysqli_free_result ($r); // Free up the resources
    }
    else // If it did not run okay
    {
        // Public Message:

        echo '<p class="error">Your submissions could not be retrieved.  We
            apologize for any inconvenience.</p>';

        // Debugging message:

        echo '<p>' . mysqli_error($dbc) . '<br /><br />Query: ' . $q . '</p>';

    } // End of if ($r) IF.



}

//END DOWNLOAD HANDLER ******************************************************


    mysqli_close($dbc); // Close the database connection



if(isset($_GET['id'])) {
// Get the ID
    $id = intval($_GET['id']); //var_dump($id);

    require_once ('../mysqli_connect.php'); //Connect to the db

// Fetch the file information

    if($stmt = $mysqli -> prepare("SELECT `file_type`, `size`, `title`, 'content', 'upload_id'
            FROM `upload`
            WHERE `upload_id` =?")) {

      /* Bind parameters
         s - string, b - boolean, i - int, etc */
      $stmt -> bind_param("sissi", $file_type, $size, $title, $content, $upload_id);

      /* Execute it */
      $stmt -> execute();   /*FINISH PREPARED STATEMENTS*/

      /* Bind results */
      $stmt -> bind_result($result);

      /* Fetch the value */
      $stmt -> fetch();

      //echo $user . "'s level of priviledges is " . $result;

      /* Close statement */
      //$stmt -> close();


        if($result) {
            // Make sure the result is valid
            if (mysqli_num_rows($result) > 0) {
            // Get the row
                $row = mysqli_fetch_assoc($result);
                //var_dump($row);
                //$data = $row;

                $place = './uploads/'.$_SESSION_['email'].'/';
                $thefile = $place.$row['title'];
                $realfile = $thefile;
                $thetitle = $row['title'];
                $thesize = $row['size'];

               require_once('./download.php');
               filedownload();






            }
            else {
                echo 'Error! No such ID.';
            }

            // Free the mysqli resources
            mysqli_free_result($result);
        }
        else {
            echo "Error! Query failed: <pre>{$dbc->error}</pre>";
        }
        mysqli_close($dbc);
        $stmt -> close();
            }




    }


                    ?>

Answer 1

你创建了一个函数filedownload()，但你从未调用它，所以它的主体永远不会被执行。您也永远不会定义$realfile，即您要发送的文件的路径。

调用你的函数：

<?php
  require_once ('./newpub_profile.php');
  $thetitle = $row['title'];
  $thesize = $row['size'];

 function filedownload() { 
    GLOBAL $thesize, $thetitle;
    header("Content-Type: application/msword");
    header("Content-Disposition: attachment; filename=".$thetitle);
    header("Content-Length: ".$thesize);
    header("Content-Transfer-Encoding: binary");
    readfile($realfile);
 }

 filedownload();
?>

虽然似乎没有理由首先在函数中使用它：

<?php
  require_once ('./newpub_profile.php');
  $thetitle = $row['title'];
  $thesize = $row['size'];

  header("Content-Type: application/msword");
  header("Content-Disposition: attachment; filename=".$thetitle);
  header("Content-Length: ".$thesize);
  header("Content-Transfer-Encoding: binary");
  readfile($realfile);
?>