C++: How to execute a function if a user has not pressed a button

Question

I am trying to make an adjustable clock (where you have to set the time manually). I need to add a function that if the user has not pressed a button after 1 second, then the seconds variable updates and the clock prints. Then I need the screen to clear and start all over. I am using Eclipse on macOS so kbhit() and system(“CLS”) do not work. Any help would be greatly appreciated. Here is what I have so far:

#include <iostream>
#include <iomanip>
#include <ctime>
#include <cstdlib>
#include <limits>

void MenuDisplay();
void Clock12(int hrs, int mins, int secs);
void Clock24(int hrs, int mins, int secs);
void Clocks(int hrs, int mins, int secs);
void Wait();//FIXME

int main() {

//Declare variables
int hours = 23;
int minutes = 58;
int seconds = 50;
int userOption = 0;
string quit;
bool counting = true;

cout << string(100, '\n');


//Loop to gather and use input from user
while (userOption != 4) {
   userOption = 0;
 //waits for user to press enter
   //Wait();

 //function to display the menu options
   MenuDisplay();

    cout << "             Please pick an option (1-4): ";
    cin >> userOption;

         switch (userOption) {
       case 1:
          ++hours;
          if (hours > 23) {//resets hours in case > 24
              hours = 0;
          }
          counting = false;
          break;

        case 2:
           ++minutes;
           break;

        case 3:
           ++seconds;
           counting = false;
           break;

        case 4:
           quit = "The clocks are set. Goodbye.\n";//For readability
           counting = false;
           break;

        default:
           cout << "Please enter a valid option (1-4)." <<endl;
           counting = false;
           break;
    }

        if (seconds > 59) {
       seconds = 0;
       ++minutes;
    }
    if (minutes > 59) {
    minutes = 0;
    ++hours;
    }

    //FIXME: This is the best I could do.
    //I am not sure why, but all the 
    //other functions for clearing a      screen were not working.
    //I tried at least 6 other methods. None worked.

    cout << string (100, '\n');



//Starts clock
counting = true;

cout << quit;
Sleep(1);
cout << string(100,'\n');
ClockRunning(hours, minutes, seconds, counting);

void Clocks(int hrs, int mins, int secs) {// Prints Clocks

//set border size
int hours = hrs;
int minutes = mins;
int seconds = secs;
cout << "**************************   **************************"
<< endl;
cout << "*      12-Hour Clock     *" 
<< "   *      24-Hour Clock     *" << endl;
Clock12(hours, minutes, seconds);
Clock24(hours, minutes, seconds);
cout << "**************************   
**************************" <<     endl;


 }

void MenuDisplay() {// Menu Options

cout << "              " << "**************************" << endl;
cout << "              " << "* 1-Add One Hour         *" << endl;
cout << "              " << "* 2-Add One Minute       *" << endl;
cout << "              " << "* 3-Add One Second       *" << endl;
cout << "              " << "* 4-Exit                 *" << endl;
cout << "              " << "**************************" << endl;

}

void Clock12(int hrs, int mins, int secs) {// 12-hour clock

int seconds = secs;
int minutes = mins;
int hours = hrs;
bool isAM;
string PM;

if (hours < 12) {
   isAM = true;
}

if (hours > 12) {
   hours -= 12;
   isAM = false;
}

if (hours > 12) {
   hours = 0;
}

if (hours == 0) {
   hours += 12;
}

if (isAM) {
   PM = "AM";
}

else if (!isAM) {
   PM = "PM";
}



cout << "*       " << setw(2) << setfill('0') << hours << ":"
<< setw(2) << setfill('0') << minutes << ":"
<< setw(2) << setfill('0') << seconds << " " // <<endl;
<< PM << "      *";
}

void Clock24(int hrs, int mins, int secs) {// 24-Hour Clock

int hours = hrs;
int minutes = mins;
int seconds = secs;

if (seconds > 59) {
    seconds = 0;
    ++minutes;
}

if (hours > 23) {
    hours = 0;
}

cout << "   *        " <<
setw(2) << setfill('0') << hours << ":"
<< setw(2) << setfill('0') << minutes << ":"
<< setw(2) << setfill('0') << seconds <<  "        *" << endl;
}

void Wait() {// Waits for user to press enter
std::cout << "Press ENTER to display the menu.\n";
std::cin.ignore( std::numeric_limits 
<std::streamsize> ::max(), '\n'   );

 }

 int Sleep(float seconds = 1) {// Sleeps for 1 second
clock_t startClock = clock();
float secondsAhead = seconds * CLOCKS_PER_SEC;

while (clock() < (startClock + secondsAhead) ){}
return 1;
}


void ClockRunning(int hrs, int mins, int secs, int stop) {
int hours = hrs;
int minutes = mins;
int seconds = secs;
bool counting = true;
int stopped = stop;

while (counting) {//FIXME:Escape the loop 
    ++seconds;

    if (seconds > 59) {
       seconds = 0;
       ++minutes;
    }

    if (minutes > 59) {
    minutes = 0;
    ++hours;
    }



   Clocks(hours, minutes, seconds);
   Sleep(1);
   cout << string (100, '\n');

    if (stopped == 0) {
        counting = false;
    }
}
}

Flowchart of the Code:

Answer 1

On Mac and Linux systems you can clear the console screen using:

system("clear");

"CLS" is just for Windows.