#include <iostream>
#include <signal.h>
#include <stdio.h>
#include <string.h>

using namespace std;

void  HitMe() {
    static int calls = 1;
    cout << "Hit me call number " << calls << endl;
    raise(SIGUSR1);
    calls++;
    cout << endl;
    return;
}

void USR1Handler(int n) {
   static int count = 1;
   cout << "USR1 signal has been handled " << count << " times " << endl;

   count++;
   if (count == 3) {
      cout << endl;
      cout << "Calling HitMe in the signal handler " << endl;
      HitMe();
   }
   cout << "Exiting the signal handler " << count-1 << endl;
   return;
}

void SignalReport (sighandler_t sig) {
    if (sig == SIG_ERR) {
        perror("signal"); 
    } else if (sig == SIG_DFL) {
        cout << "Just replaced the default signal handler " << endl;
    } else if (sig == SIG_IGN) {
        cout << "Just replaced IGNORE " << endl;
    } else {
        cout << "Replaced a custom signal handler" << endl;
    }
    return;
}


int main() {
    sighandler_t sig;

    cout << "Using SIGUSR1  which is " << SIGUSR1 << endl;
    cout << "This is described as " << strsignal(SIGUSR1) << endl;

//    HitMe();

    cout << endl;
    cout << "Using the custom signal handler " << endl;
    sig = signal(SIGUSR1, USR1Handler);
    SignalReport(sig);

    HitMe();

    cout << "Setting the signal handler to ignore " << endl;
    sig = signal(SIGUSR1, SIG_IGN);
    SignalReport(sig);

    HitMe();

/*
    cout << "Seting the signal handler to default " << endl;
    sig = signal(SIGUSR1, SIG_DFL);
    SignalReport(sig);

    HitMe();
*/

    cout << "Using the custom signal handler " << endl;
    sig = signal(SIGUSR1, USR1Handler);
    SignalReport(sig);


    HitMe();
    HitMe();

    return 0;
}