#include<stdio.h> 
#include <sys/types.h> 
#include <signal.h> 
#include <unistd.h>
#include <iostream>
#include <cstdlib>
using namespace std;

//this function prints a message and changes the function to handle the SIGINT command to kill_func() 
void myFunction(int sigVal);

// handles after alarm alarm
void alarmFunction(int ignore);
int child;

// handles SIG_INT while the alarm is active
void ignoreFunc(int ignore);
//This function kills the process that makes a call to this function
void kill_func(int killSignal);

// handles killing the child
void childKillFunc(int kill);

int main()
{
    child = fork();
	// ignore the SIGINT signal
	// .. SIGINT is ctrl+c 
	// .. ignoreFunc is the user-defined signal handler
	// 
	signal(SIGINT,ignoreFunc);
	// for alarm signal, call function alarmFunction() 
	// .. means when alarm goes off, alarmFunction will be called
	
	signal(SIGALRM,alarmFunction);
	//set alarm for 15 seconds from now
	alarm(10);
	//printf("This gets printed as soon as alarm is called\n");
	// just running infinitely
	while(1);
}

void myFunction(int sigVal)
{
	printf("Received signal %d\n", sigVal); 
	printf("Now you can kill me..\n"); 
	signal(SIGINT,kill_func);
}

void alarmFunction(int ignore)
{ 
	if (child== 0)
	{
		//define user signal and kill(child, USRSIG1) to send signal to child

		signal(SIGINT,SIG_IGN);
		signal(SIGUSR1, childKillFunc);
	}
	else
	{
		printf("Received signal %d\n", ignore); 
		printf("Now you can kill me..\n");
		signal(SIGINT,kill_func);
	}
}

void kill_func(int killSignal) 
{
	if(child == 0)
	{

	}
	else
	{
		//define user signal and kill(child, USRSIG1) to send signal to child

		printf("Sending signal to child\n");
		kill(child, SIGUSR1);
		printf("Received kill signal %d\n",killSignal); 
		printf("\tDying process %d\n",getpid());
		exit(0);
	}

}

void childKillFunc(int kill)
{
	if (child == 0)
	{
		cout << "Received kill signal" << endl;
		cout << "Child Process " << getpid() << " is dying" << endl;
		exit(0);
	}
	
}

void ignoreFunc(int ignore)
{
	
	if(child == 0)
	{
	}
	else 
	{
		cout << "Can't kill processes now\n";
	}
}