I recently needed to force a PDF to download using Apache. The default behaviour for most browsers is to try to open the PDF inside the browser itself. This is fine for a small PDF or for powerful machines - but a large PDF on even a modest machine can often lock the browser up. This needed fixing!
After 20 minutes of perusing the Apache documents, I happened across the FilesMatch option which takes Regular Expressions. Regular Expressions are cool things which pattern match; you give it a rather complicated (yet logical) pattern and it matches it for you. Initially I used something like this...
<Files *.pdf>
ForceType application/pdf
Header set Content-Disposition attachment
</Files>
This worked PERFECTLY - except some files had upper-case extensions and some had lower and I could see situations in the future where combinations of upper and lower case would be used too - just to piss me off! Because of this, not even this would work...
<FilesMatch "\.(pdf|PDF)$">
ForceType application/pdf
Header set Content-Disposition attachment
</FilesMatch>
That would match perfectly - as long as it was an EXACT match on upper OR lower case.
I was reaching the end of my patience - that is until I read the Using Character Classes on PerlDoc.
This showed me that I could force the RegEx (short for Regular Expressions) to match in a case-insensitive manner. This lead me to the following...
<FilesMatch "\.(?i:pdf)$">
ForceType application/pdf
Header set Content-Disposition attachment
</FilesMatch>
However this only worked in proper browser - and the bulk of the world are sadistic enough to use Internet Explorer based ones. For some readon - if Internet Explorer sees the content type "Application/PDF" it will simply open it up in the reader. The solution? Why not pretend its a bog standard Octet Stream - just like a Zip file? After all - that's basically all it is, a binary file... A steam of bytes.
<FilesMatch "\.(?i:pdf)$">
ForceType application/octet-stream
Header set Content-Disposition attachment
</FilesMatch>
And there you have it... A perfectly working modification to force all PDF files to download - this will work for any file extensions you chose to put into the FilesMatch argument!


thanks
Hey! That worked perfectly, thanks! You might indicate that one needs mod_headers to use
Header set.mod_headers, nice tip!
Thanks for that... I didn't have a problem as my Apache configs tend to have everything enabled by default ;-)
Where to put it?
Do I put this code in the .htaccess file or what?
It can go anywhere
You can put this code in either the htaccess or the vhost configuration for your server.
You can read more about FilesMatch at the Apache Document page.
Hey, great explanation. I'd
Hey, great explanation. Thanks for the well written explanation and for the code sample(s).
Force PHP Download
Really Interesting document, but how would you use that if apache is a proxyserver?
Hi, I can't get this to
Hi,
I can't get this to work in .htaccess, I asked around and someone said that the regex was wrong.
Any idea how I can get it to work?
For this technique applied
For this technique applied to other web servers and languages such as PHP, check out http://www.stuvel.eu/pdfdownload ;-)