fly: frequently asked questions

Q: Can you send me a copy of fly via email?

A: Not right now. Maybe later.
Q: All these different copies of fly are confusing. I'm using a Windoze 99 computer and my ISP has Lunix. What version of fly do I need?

A: Check with your Internet Service Provider to see what version of unix and on what platform they are running. You should then be able to download the appropriate pre-compiled copy of fly. You might even like to ask them to install it for you. If no pre-compiled copy is available, you should ask them to compile and install it.
Q: I'm using a Silicone Picture RSA4500 computer running Lunix. Do you have a copy of fly compiled for my platform?

A: If it's not on the Download and Installation page, the answer is no. Check with your Internet Service Provider or System Administrator to see if they will compile it for you.
Q: How can I create animated GIFs with fly?

A: You can create the still images with fly, and then join them together with a tool like whirlgif.
Q: I can't get this counter program to work. What's wrong?

A: Probably nothing is wrong with fly. To check that fly is working, change to the directory where it is located and type ./fly -h and you should get a 'Quick Reference to Directives' screen.

Please note that I am not the author of any counter program. In fact, I strongly recommend against using them. Use a web log analysis program like pwebstats. At any rate, I can not offer any support for a program that was written by someone else. Please do not email me asking to get your counter working, because all you will get is the URL of this page. Contact the author of the counter program, or try to work out the problem yourself. General CGI debugging information is available at <http://www.cgi-resources.com/>.

Q: I'm using fly on Windows and the images are corrupted. What's wrong?

A: Windows needs to have output files opened in binary mode. See the following perl example from the Perl for Win32 FAQ http://www.activestate.com/support/faqs/win32/perlwin32faq7.html.

7.3. How do I return a graphics file from a CGI script?

One of the big differences between UNIX and Win32 platforms is
that on Win32 there's a difference between text or ASCII files
and binary file. To return a graphics file, you need to specify
that the file is a binary file, and that the standard output
stream should accept binary data. Try something like this: 

    $MY_FILE_NAME = 'Penelope.jpg';
    $CHUNK_SIZE = 4096;

    open( MY_FILE, "<$MY_FILE_NAME" )
         or die( "Can't open $MY_FILE_NAME: $!\n" );

    print "Content-type: image/jpeg\r\n";
    print "\r\n";

    binmode( MY_FILE ); # These are crucial!
    binmode( STDOUT ); 

    while ( $cb = read( MY_FILE, $data, $CHUNK_SIZE ) )
    {
        print $data;
    }

    close( MY_FILE );