feature request: add -forward-only option to not start engine if there is no engine already running

[illwieckz]

Right now we can do things like daemonded +devmap <parpax> to forward the command to an existing engine already running. But if the engine is not already running, the engine will start.

This is sometime wanted, for example daemon +connect <servername> will either connect to the server, or start the game and connect to the server, which is the mechanism used by the unv:// protocol, which is very cool.

This is sometime unwanted, like if you're a server owner and all you want to do is to forward a command to an existing server, and you only want to forward commands to existing servers. For example, let's say you have a systemd service managing the daemonded server, you may want to do sudo -u unvanquished daemonded +say hello and be sure the engine doesn't start an instance in your current tty if for some reason the engine is not running yet.

So I suggest to implement an option like -forward-only that would not start the engine if there is no existing instance to forward the command to.

[slipher]

Yeah I’ve thought about this too. We should have a -forward that errors if the engine isn’t already running and a -noforward that errors if the engine is already running.

[illwieckz]

Here is another day I would love to have this!

[illwieckz]

We should have a -forward that errors if the engine isn’t already running and a -noforward that errors if the engine is already running.

I like that.