MacOS send keystroke to background application

Send_Key_To_Background_Application.swift

import Foundation
import CoreFoundation

// all keycodes: https://gist.github.com/swillits/df648e87016772c7f7e5dbed2b345066
let KeyCode_R: UInt16 = 0x0F;
let KeyCode_N: UInt16 = 0x2D;

let src = CGEventSource(stateID: CGEventSourceStateID.hidSystemState)
let kspd = CGEvent(keyboardEventSource: src, virtualKey: KeyCode_R, keyDown: true)   // space-down
let kspu = CGEvent(keyboardEventSource: src, virtualKey: KeyCode_R, keyDown: false)  // space-up

// real PID-s from command 'ps -ax | grep {Application}' - e.g. for example 3 different processes
let pids = [ 69885 ]; 

// send repeat with interval
let interval = 5.0;
var start = CFAbsoluteTimeGetCurrent();
repeat {
    if (CFAbsoluteTimeGetCurrent() - start >= interval) {
        start = CFAbsoluteTimeGetCurrent();
        print("sending to pid: ", pids[0]);
        kspd?.postToPid( pid_t(pids[0]) ); // convert int to pid_t
        kspu?.postToPid( pid_t(pids[0]) );
    }
} while (true)

// send only once
// for i in 0 ..< pids.count {
//     print("sending to pid: ", pids[i]);
//     kspd?.postToPid( pid_t(pids[i]) ); // convert int to pid_t
//     kspu?.postToPid( pid_t(pids[i]) );
// }