Sending a file through STDOUT using HTTP

hcubed has asked for the wisdom of the Perl Monks concerning the following question:

I'm having some trouble with some CGI/Perl code on my webserver. The following function uses the Archive::zip module to zip a directory on the fly and send it to STDOUT when the client clicks on a certain link. It zips the file correctly but I think I have something wrong with the headers because when the download dialog box pops up it doesn't have a filename to save and it thinks the MIME type is "httpd/unix directory" (at least in Firefox). It then saves it as a randomly generated filename without an extension. Any ideas as to how to send the headers correctly so it knows it's a zip file and uses the filename I specify?

sub fetch_archive {
    my $path = "path/to/file/";
    my $filename = "data.zip";
    my $zip = Archive::Zip->new();

    $zip->addTree( $path, '' );
    print "Content-type: text/plain\n" .
          "Content-Disposition: attachment;$filename\n\n".
    $zip->writeToFileHandle( 'STDOUT', 0 );

    return Apache::OK;
}
[download]

Comment on Sending a file through STDOUT using HTTP Download Code

Replies are listed 'Best First'.
Re: Sending a file through STDOUT using HTTP by TedYoung (Deacon) on Feb 17, 2005 at 21:53 UTC
You need to specify the content type as application/zip: `print "Content-type: application/zip\n" . "Content-Disposition: attachment;$filename\n\n";` [download] Ted Young `($$<<$$=>$$<=>$$<=$$>>$$) always returns 1. :-)`	[reply] [d/l] [select]
Re^2: Sending a file through STDOUT using HTTP by hcubed (Initiate) on Feb 17, 2005 at 22:01 UTC
That's what I thought too. I guess I should've included the fact that I've tried several different MIME types but that never seems to affect what the browser thinks it is. No matter what headers I put in there it always just thinks it's an "httpd/unix-directory" with no filename.	[reply]
Re^3: Sending a file through STDOUT using HTTP by TedYoung (Deacon) on Feb 17, 2005 at 22:10 UTC
Just noticed this too. Change your content-disposition line as follows: `"Content-Disposition: attachment; filename=\"$filename\"\n\n";` [download] Ted Young `($$<<$$=>$$<=>$$<=$$>>$$) always returns 1. :-)`	[reply] [d/l] [select]
Re^4: Sending a file through STDOUT using HTTP by hcubed (Initiate) on Feb 17, 2005 at 22:26 UTC
Re: Sending a file through STDOUT using HTTP by Errto (Vicar) on Feb 17, 2005 at 23:59 UTC
The correct way to set the content type and disposition is (untested) `print "Content-type: archive/zip\n" . "Content-Disposition: attachment; filename=$filename\n\n"; binmode STDOUT; $zip->writeToFileHandle( \*STDOUT, 0 );` [download] There's a few points here: The correct way to set the content-disposition is with the filename= part but without the quotes around the filename (I think). With your current code you are trying to append the result of writeToFileHandle to your string. I think you mean ";" instead of "." writeToFileHandle expects a filehandle reference, not a string corresponding to the name of a filehandle. You should set `binmode` on a filehandle before writing binary data to it. Give that a shot.	[reply] [d/l] [select]
Re^2: Sending a file through STDOUT using HTTP by TedYoung (Deacon) on Feb 18, 2005 at 00:51 UTC
Good points! But, I did have to use the quotes around the file name in the past to handle files with spaces in their names. Ted Young `($$<<$$=>$$<=>$$<=$$>>$$) always returns 1. :-)`	[reply] [d/l]
Re^2: Sending a file through STDOUT using HTTP by Anonymous Monk on Feb 18, 2005 at 16:27 UTC
Excellent points and I definitely appreciate the info. I now have: `$zip->addTree( $path, '' ); print "Content-type: application/zip\n" . "Content-Disposition: attachment;filename=\"$filename\"\n\n"; binmode STDOUT; $zip->writeToFileHandle( \*STDOUT, 0 );` [download] Unfortunately the browser is still seeing it as a "httpd/unix-directory" and not getting a filename. I tried both with and without quotes on the filename. Any other ideas? Stupid MIME types...	[reply] [d/l]
Re^3: Sending a file through STDOUT using HTTP by hcubed (Initiate) on Feb 18, 2005 at 16:28 UTC
Sorry, forgot to login. The above post was me.	[reply]
Re^3: Sending a file through STDOUT using HTTP by Errto (Vicar) on Feb 18, 2005 at 17:34 UTC
I did a quick search on Google and it looks like the "httpd/unix-directory" think might be an Apache configuration issue. Are you sure your CGI code is actually getting executed? Maybe add something like `print STDERR "My CGI called here"` and see if that message shows up in your Apache error log.	[reply] [d/l]
Re^4: Sending a file through STDOUT using HTTP by hcubed (Initiate) on Feb 18, 2005 at 18:07 UTC
Re: Sending a file through STDOUT using HTTP by TedYoung (Deacon) on Feb 19, 2005 at 15:04 UTC
Try it on a couple of other browsers... perhapse it is a bug in your version. Ted Young `($$<<$$=>$$<=>$$<=$$>>$$) always returns 1. :-)`	[reply] [d/l]