Force Download Only Displays in Browser, Doesn'

问题:

I can't seem to figure this out and I know it's something simple. I am building the back-end to a very basic content management system. For this specific piece, I am just trying to create a PHP link that allows for a file (the client's CV) to be downloaded.

MY PROBLEM:

When the link to download the file is clicked, instead of the browser prompting you to choose a local directory to save the file to - it simply displays the file and a bunch of symbols before and after the document's contents (I am assuming this is the file's opening and closing exif data for an application to decipher).

How could I go about forcing the browser to prompt the user for a "Save As..." box?

<?php
require("connect.php");
$query = "SELECT * FROM kb_info LIMIT 1";

$result = mysql_query($query, $link);
while ($row = mysql_fetch_array($result)) {
    $file_extension = end(explode(".", $row["extension"]));

    if ($file_extension == doc) {

        header('Content-disposition: attachment; filename='.$row["extension"]);
        header('Content-type: application/doc');
        header ("Content-Length: ".filesize($row["extension"]));
        readfile($row["extension"]);
        exit;

    }
    if ($file_extension == docx) {

        header('Content-disposition: attachment; filename='.$row["extension"]);
        header('Content-type: application/docx');
        header ("Content-Length: ".filesize($row["extension"]));
        readfile($row["extension"]);
        exit;

    }
    if ($file_extension == pdf) {

        header('Content-disposition: attachment; filename='.$row["extension"]);
        header('Content-type: application/pdf');
        header ("Content-Length: ".filesize($row["extension"]));
        readfile($row["extension"]);
        exit;

    }
}    
?>  

Many thanks,

Joshie

回答1:

I think the problem can be that there is some whitespace somewhere in the PHP files, which causes that the headers are not sent correctly and therefore you see the whole output.

I would suggest the followings steps:

1. check the "connect.php" and look for empty lines/spaces at the begining/ending of the file and remove them

2. adapt you php files that way, that you leave out the ending tag ?> at the end of the file - that way you do not get empty lines at the end of the file

3. if the above are not enough you need to check your apache and php error log and/or set up error loging, so you see also warnings - that you you would be informed if the headers are not sent correctly or if there is some other error

回答2:

Headers I use for download:

        header("Pragma: public");
        header("Expires: 0");
        header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
        header("Cache-Control: public");
        header("Content-Description: File Transfer");
        header("Content-type: application/force-download");
        header("Content-Disposition: attachment; filename=".$file); 
        header("Content-Type: application/octet-stream");
        header("Content-Transfer-Encoding: binary");
        header("Content-Length: ".$bytes."");