extra byte at start of downloaded file

michaeldw

Hi,
I'm trying to make a zip file accessible only via fpassthru for validated users.
Unfortunately, an extra byte (newline I think) is always added to the start of the file.
(If I include the length of the file in the header then the last byte is consequently lost.)
I've tried changing the headers in various ways, using things that seem to have worked for others, but to no avail.
Has anyone any ideas?
Thanks,
Michael

header("Content-Type: application/force-download");
header("Content-Type: application/octet-stream");
header("Content-Type: application/save");
header("Content-Disposition: attachment; filename=$file", "zip");
//header("Content-Length: " . filesize($pathtofile));
//header("Content-Transfer-Encoding: binary");

// dump the file and stop the script
$fp = fopen($pathtofile, 'rb');
fpassthru($fp);
fclose($fp);
exit;

Weedpacket

Is there any difference if you just use [man]readfile[/man]?

michaeldw

Thanks for the suggestion.
Unfortunately, whether readfile() or fpassthru() makes no difference. I've been kind of assuming that the leading newline is somehow added at the end of the header stuff and picked up as part of the content. (I've also tried downloading with a couple of different browsers just in case it was at the client side.)

michaeldw

OK, after applying much brainpower,
I finally noticed there was a newline at
the start of the php file just before the
"<?php" bit.

What I can't figure out is how this somehow
got to be placed after the header stuff
given that it appears before the header()
lines in the PHP code.

But no doubt there's an equally simple
explanation for that probably because
of some kind of buffering that's going
on or something (I've only just started
learning PHP and have basically done
a lot of copying and pasting of other
people's stuff...)

Weedpacket

Originally posted by michaeldw
OK, after applying much brainpower,
I finally noticed there was a newline at
the start of the php file just before the
"<?php" bit.

What I can't figure out is how this somehow
got to be placed after the header stuff
given that it appears before the header()
lines in the PHP code.

But no doubt there's an equally simple
explanation for that probably because
of some kind of buffering that's going
on or something (I've only just started
learning PHP and have basically done
a lot of copying and pasting of other
people's stuff...)

Hrrmm... that would have been my next question 🙂 Check your php.ini file; my guess is that you've got output buffering set in some fashion.