#include<stdio.h>
#include<iostream>
#include<unistd.h>
#include<sys/wait.h>
using namespace std;

string getoutput(string command){
	int fds[2]; // fds[0] is the read end, fds[1] is the write end
	pipe(fds);
	string return_value;
	pid_t pid = fork(); // fork will return twice!  Once as the parent, once as the child
	if(pid){ // In this case, we are the parent process
		close(fds[1]);
		while(true){
			char buffer[1024];
			ssize_t readlen = read(fds[0], buffer, 1024); // and this, at the same time!
			if(readlen < 1)
				break;
			buffer[readlen] = 0;
			return_value += string(buffer);
		}
		wait(0);
		close(fds[0]);
	} else { // In this case, we are the child process
		dup2(fds[1], 1);
		system(command.c_str()); // this to happen
		exit(0);
	}
	return return_value;
}

int main(){
	
	int pid = fork();
	printf("hi %d\n", pid);
	if(pid)
		return 0;

	while(1){ // This loop is what the daemon will keep doing
		string usercount = getoutput("who | grep \"^[a-Z\\-]\"* -o | sort -u  | wc -l");
		string time = getoutput("date \"+%b%d %H:%M\"");
		time[time.length() - 1] = ' ';
		usercount[usercount.length() - 1] = ' ';
		getoutput("echo " + time + usercount + " >> user_count_log");
		cout << time + usercount << endl;
		sleep(600);
	}
	return 0;
}