Add a switch to disable "Leave site?" alert

[mateuszkwiatkowski]

Is your feature request related to a problem? Please describe.
I'd like to disable alert that prevents closing terminal immediately.

Describe the solution you'd like
Add a commandline switch to ttyd, eg. --disable-leave-alert

Additional context
This is the alert in question:

[bbilas]

That's related to the beforeunload event located in html/src/components/terminal/index.tsx. Is there any easy way to control it from the C sources? If so I can take a look on it.

[tsl0922]

Take a look at the --client-option argument and SET_PREFERENCES command.

[bbilas]

@tsl0922 I guess that if it's feasible to change it via the above option you won't be interested to have this as a separate cmd arg?

[tsl0922]

Added support via 260778a, usage:

ttyd -t disableLeaveAlert=true bash

[mateuszkwiatkowski]

Thank you!