Perl CGI
 

Hi,

I am a newbie to Perl CGI. I am developing an application with a web
front end and C language module at the backend. The interface between
them is a UDP socket. I am using Perl to construct the HTML pages.
Here is what I do.

1) Show a web page and accept values from the web-user.
2) When the User presses "Submit", I construct a message and send it
across the UDP socket to the backend.
3) I wait for the response from the backend. If the response is an
error (could be because of wrong values entered by the user), I clean
up the existing page and show a new page displaying an appropriate
error message.
4) When I try to show the error html page, the contents always get
appended to the existing html page.
5) How can I clear a html page and display a new one? I tried print
$query->end_html and followed it up with a $query->start_html. Didnt
work.

Please help me. Thanks.

Re: Perl CGI
 

haribalram@yahoo.com (Hari) wrote in message news:<9fb02734.0401190136.736a7dee@posting.google. com>...
> I am a newbie to Perl CGI.

When learning several new things at once (HTTP, HTML, CGI, Perl) it
may help to learn them one at a time.

Your question has nothing to do with Perl or CGI.

Your question has to do with HTML and the HTTP request cycle.

> 4) When I try to show the error html page, the contents always get
> appended to the existing html page.
> 5) How can I clear a html page and display a new one? I tried print
> $query->end_html and followed it up with a $query->start_html. Didnt
> work.

A single HTTP request gets a single HTTP resoponse. (Ignoring
server-push, which I don't understand).

A single HTTP response has a single body (e.g. and HTML document).

There is no way in HTML to clear a document or cause an immediate
redirect without resorting to client-side scripting.

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