How to Detect Key Down Events?

General Usage
2

I found a similar question on stackoverflow.

Based on that you could do something like this

using REPL

# Run listener as separate task using channels, put keypresses in channel for main loop
function key_listener(c::Channel)
    t = REPL.TerminalMenus.terminal
    while true
        REPL.Terminals.raw!(t, true) || error("unable to switch to raw mode")
        keypress = Char(REPL.TerminalMenus.readkey(t.in_stream))
        REPL.Terminals.raw!(t, false) || error("unable to switch back from raw mode")
        put!(c, keypress)
    end
end

function main()
    channel = Channel(key_listener, 10) # Start task, 10 is buffer size for channel
    stop = false
    while !stop
        println("Doing some long calculation")
        sleep(1)
        while !isempty(channel) # Process all keypresses
            c = take!(channel)
            if c == 'q'
                println("quitting")
                stop = true
                close(channel)
                break
            else
                println("$c is not a recognized command")
            end
        end
    end
end