Mojolicious has a sample web socket in the cookbook guide.

Actually I made a whole presentation on this topic complete with GitHub repo of all the examples I showed (and the slide show itself was mirrored onto each person's browser, synchronized to me flipping from one slide to the next)

The simplest example is probably this client and controller action.

Dated but workable, Chapter 4 of Web Client Programming with Perl (freely available as part of the O'Reilly Open Books Project) has exactly an example of writing a Perl web client using sockets.

The perlipc documentation has example network clients and servers, and the examples in IO::Socket are quite good as well (if you want to go core but a step up from direct sockets).

Hope that helps.

Socket? Do you mean a websocket? See Connecting OBS to my home automation network on how to write a Perl client.

As for HTML: Browsers only allow Javascript. See Javascript Websocket

Well, technically, you could fiddle with something like emscripten to cross-compile any C program (inkluding Perl) to Javascript. That's a MAJOR undertaking but it's technically possible. That is how the people at archive.org have cross-compiled the DOSBox emulator so that you can play old DOS games on their website. You still wouldn't be able to use raw network sockets.

I've done a fair bit with Websockets, see BaseWebSocket.pm and it's corresponding HTML template basewebsocket.tt. All this is pretty tied to my own framework, but if you need any help doing something similar in yours, feel free to ask.

I've found nothing that shows the client side (the HTML page in the browser) that could connect with the Perl socket server script.

Was Fletch's suggestion what you were looking for or did you want to write the client side in WebPerl rather than Javascript?

A web browser client can only run javascript given by the server in the HTML severed. Javascript does not allow raw access to sockets, it only allows certain HTTP use and certain protocols like websockets.

HTTP is limited to a client request and a server response (a server cannot just send to a client - the client has to request it i.e. ‘fetch’ .

To do a HTTP fetch in javascript use the fetch api (https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) which will be a http request to your server.

If you need the server to be able to push data to the client - you will need to use web sockets (https://developer.mozilla.org/en-US/docs/Web/API/WebSocket). In this case the server would server over http javascript that tells the client to open a websocket to be able to receive from server. on the perl side you would then need a websocket server (https://metacpan.org/pod/Net::WebSocket::Server) in addition to the http server.