1) make matrix; 2) ./matrix

matrix.cpp

#include <iostream>
#include <string>
#include <chrono>
#include <thread>
#include <cstdlib>
const int width = 158;        // Width of terminal window
const int flipsPerLine = 5;    // No. of columns changed per line
const int millisecondsOfSleep = 50; // Delay between lines in millisecond
int main() {
    srand(time_t(NULL));
    bool switches[width] = { true };
    const std::string garbage = "1234567890/*-+.,./;[]\\=_~`!@#$%^&*()";
    const auto glen = garbage.size();
    while (true) {        // Waiting for Ctrl-C
       for (int i = 0; i != width; ++i) {
           if (switches[i]) {
           std::cout << garbage[rand() % glen];
           } else {
           std::cout << ' ';
           }
       }
       std::cout << std::endl;
       for (int i = 0; i != flipsPerLine; ++i) {
           int x = rand() % width;
           switches[x] = (switches[x]) ? false : true;
           // Flipping switches
       }
       std::this_thread::sleep_for(std::chrono::milliseconds(millisecondsOfSleep));
    }
    return 0;
}