STDOUT and mod

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

I have a follow-up question to one I asked very recently Suggested file name for CGI output, though basically unrelated (hence the new node). I have the following code to make gzipped ouput from a CGI.

        use Compress::Zlib;
        if($out eq 'gz'){
            binmode STDOUT;
            print("Content-type: application/x-gzip\n\n");
            my $gz = gzopen(\*STDOUT, "wb")           
                or die "Cannot open stdout: $gzerrno\n" ;
            foreach my $line (@lines){ 
                $gz->gzwrite($line)
                    or die "error writing: $gzerrno\n" ;
            }
            $gz->gzclose; 
        }
[download]

With some help from the Monks, things work now as I want them as a stand-alone CGI. However, I'm now trying to do the same thing under mod_perl. I now see that STDOUT is tied in mod_perl, which prevents this techique from working there. What would be the best approach to get gzipped output from my script under mod_perl?

-a

Comment on STDOUT and mod_perl Download Code

Replies are listed 'Best First'.
Re: STDOUT and mod_perl by philcrow (Priest) on Aug 29, 2006 at 14:17 UTC
Since you probably need a handle, but you can't use STDOUT and don't want to use a real file, try Tie::Handle::ToMemory which allows you to work with a handle, but collect the data in a scalar. Once the compressed output is in the scalar, you can print it as normal so mod_perl will be happy. Phil	[reply]
Re: STDOUT and mod_perl by Anonymous Monk on Aug 29, 2006 at 13:39 UTC
RTFM? mod_perl gzip output: CGI::Compress::Gzip mod_perl: Web Content Compression FAQ	[reply]
Re^2: STDOUT and mod_perl by albert (Monk) on Aug 29, 2006 at 13:49 UTC
This is not exactly what I want, and I've already looked at these things. I am not looking to compress all the output in response to the request from the browser. I am looking to have my CGI give output as either 'gzipped' or as 'text' depending on an option selected by the user. If selected, I want the output to come as an file attachment. -a	[reply]
Re^3: STDOUT and mod_perl by Anonymous Monk on Aug 29, 2006 at 14:40 UTC
Look a little harder, CGI::Compress::Gzip works with mod_perl: Note that the Zlib library on which this code is ultimately based requires a fileno for the output filehandle. Where the output filehandle is faked (i.e. in mod_perl), we instead use in-memory compression. This is more wasteful of RAM, but it is the only solution I've found (and it is one shared by the Apache::* compression modules).	[reply]