[Catalyst] Force server to send data to browser....

Nope, everything is printed in a big print statement in finalize().
(Actually, it's not that big... it's only one line. But you know what I
mean.) If you think about it, this is necessary because you can change
headers or the body at any time in the request cycle... and you can't
unsend data.

However, nothing is stopping you from printing to {*STDERR}, using
"warn", or running myapp_server.pl under perl's debugger. Printing
debugging information to the browser is completely unnecessary.

Regards,
Jonathan Rockway

So what?s `finalize_headers` do?

Regards,

Fair enough. I'm technically incorrect, but my answer holds.
finalize_headers and finalize_body both get called after the last end
action. (I know this experimentally because I mess with the headers in
my Root.pm/end :)

Good question, not sure how you'd do it with Catalyst.
I've done this before to show output from a lengthy batch program, using
CGI.pm, sending the header then the start of the output followed by a
flushed space char every minute to stop the browser timing out. Like a "tail
-f" on a log file.

Regards, Peter

check this thread.
http://lists.rawmode.org/pipermail/catalyst/2006-June/008315.html