Shell Programming and Scripting

I want to write a sh/perl script to login to a web site for example

(from unix) go to http://login.yahoo.com/
pass userid/password
then sign out

Thanks in advance.

Yes, it's possible, but why would you want to do this?

I just gave an example of "YAHOO" i have a 4-tier application... I want to have script login there and then perform some browsering....

What you have to do is probably somthing like the following:

Monitor all HTTP headers you send and recieve in your request/response cycles with a tool like Live HTTP Headers for Firefox.

Write a script that send a request, then looks in the response for certain values in the headers or the body, and then perform your next request.

There are tools to automate this, maybe even Live HTTP Headers can do this for you.

This is not possible with sh (unless you use an already open socket), but with Perl it is.