I need to develop a server side application that opens sockets and manages communication with multiple clients. Previous answers have told me this is possible using a single script file, which loops forever.
Is this possible using only a PHP/Perl/Python hosting service? or would I need a VPS or shell access?
Any help is appreciated since I've never worked with sockets before. Thanks for your time.
It would make your host very unhappy since their CPU time is valuable! If you use shared hosting, your host might just kick you out for such a solution! (Read your contract for the fine details.)
I think it could be possible but it depends on the setup of your host, plus the permissions your host are granting you. And most will be unhappy about anything that runs forever. (They prefer to see just short, simple applications.)
Cheap Perl/PHP hosting services don't want you running your own long-running processes.
This means you will need a VPS (which obviously includes shell account since you can do anything you want on your private server). A few VPS providers might block outgoing IRC port but I think that is rare.
Linode and Slicehost/Rackspace are just two examples very very well run VPS service providers and I guarantee you can run your own socket application on them.
Usually the service firewall will block any unexpected ports, or if they are not doing it now they will start doing it after they figure out what you are doing and decide they don't like it.