force download - should be simple!

vivianp79

Hi Everyone,

Im having difficulty forcing a download to work. I can get the download dialog box to open when a user clicks on a link, and I can get the user to save the file locally when they click Save button, but for some bizarre reason I cant open a file through the download dialog box!

I am getting a "File not found." error.

Okay, so here is an example of what I am doing.

The user clicks on the following link:
echo "<a href='file_detail.php?file=$file'><font color='#CC0000'>DOWNLOAD FILE</font></a>";

where $file = uploads/Caricature.jpg

This 'refreshes' the page (file_detail.php) and then at the top of the page I have the following script:

if ($file !=""){
$file = explode("uploads/",$file);
$file = $file[1];
$fp = fopen("uploads/$file", "r");
$contents = fread($fp, filesize("uploads/$file"));
readfile("uploads/");
header("Content-type: application/octet-stream");
header("Content-Disposition: attachment; filename=$file");
print($contents);

    exit; 
    fclose($fp);

}

Okay, the file that I am trying to open is located in the "uploads/" directory.

I dont understand why it can locate the file and save it locally, but it cannot locate the file and open it from the server!

Any ideas? It seems like such an easy thing to do..

-vivianp79

vivianp79

Okay, ive sortof got it working but now I have a different error:

Warning: Cannot add header information - headers already sent by (output started at /TNAWeb/kworld/public_html/corporate/file_detail.php:56) in /TNAWeb/kworld/public_html/corporate/file_detail.php on line 60

I can download files and save them locally and I can open and view them BUT when I try to do this in succession I get header errors.

The code I am using is:

$filename=$file;
$file = explode("uploads/",$file);
$file = $file[1];

if(file_exists($filename)){
$FILECMD = '/usr/bin/file';
$contentType = '';
$fp=popen("$FILECMD -bin $filename", 'r');
if (!$fp) $contentType='application/octet-stream';
else {
while($string=fgets($fp, 1024)) $contentType .= $string;
pclose($fp);
}
if(strpos($HTTP_SERVER_VARS['HTTP_USER_AGENT'], 'MSIE')){
// IE cannot download from sessions without a cache
header('Cache-Control: public');
}
header("Content-type: $contentType");
header("Content-Disposition:attachment; filename=\"".$file."\"");
header("Content-length:".(string)(filesize($filename)));

$fd=fopen($filename,'rb');
while(!feof($fd)) {
print fread($fd, 4096);
}

fclose($fd);
header("Connection: close");

}else{
print "File Not Found";
}

To give you more background on my script, I have an include file a the top of the page that handles the style of all my pages. It has already created 'headers' and I am calling the header function again within the same page to handle the popup of the download code (hope that made sense!).

Do I have too many header sessions open? Have I confused the browser (or myself for that matter!).

If I wait a little while before opening or saving the same file again it seems to work. Is there some sort of a built-in timeout?

Any help would be rewarded with a great big hug from me :-)

-vivianp79

daveyboy

There must be absolutely no output to the browser before your file. Not even a blank line outside of PHP tags, or PHP will automatically send the content-type: text/html; headers and you're done for. Have a good look through your scripts to make sure there are no such lines and no output.

Secondly, you should use fpassthru() to send your file to the browser - fread() sometimes inserts backslashes depending on magic quotes settings, and that'll screw any binary files.

I don't know what browser you're using - they all react a little differently to PHP download scripts. I suggest you try to send a more precise MIME type than application/octet-stream, so that the browser knows what application it should open it with - not all browsers use the filename / name headers to determine file type. You'll have to check the extension of the file and send a corresponding MIME type.

See attached text file for the array I use to get MIME type