Child.cpp

#ifdef _MSC_VER

#define _CRT_SECURE_NO_WARNINGS
#include <cstdlib>
#include <windows.h>

#else

#include <unistd.h>
#include <stdio.h>
#include <cstring>
#include <sys/types.h>
#include <signal.h>

#endif

#include <string>
#include <fstream>
#include <ctime>
#include <cstdlib>
#include <iostream>
using namespace std;

#define FILE_NAME "log.log"
#define LOG_DEBUG_LEVEL 2
#define LOG_ERROR_LEVEL 1
#define LOG_FATAL_LEVEL 0
int log_level = 2;

void setLevel()
{
	switch (log_level)
	{
	case LOG_DEBUG_LEVEL:
	{
		time_t seconds = time(NULL);
		tm* timeinfo = localtime(&seconds);
		fstream file(FILE_NAME, ios::app);
		file << asctime(timeinfo) << "some_debug_info" << endl;
		file << asctime(timeinfo) << "Error: index out of range." << endl;
		file << asctime(timeinfo) << "Error: could not find file." << endl;
		file << asctime(timeinfo) << "Fatal_error: processes must be closed." << endl;
		file.close();
		cout << "some_debug_info" << endl;
		cout << "Error: index out of range." << endl;
		cout << "Error: could not find file." << endl;
		cout << "Fatal_error: processes must be closed." << endl;
		break;
	}
	case LOG_ERROR_LEVEL:
	{
		time_t seconds = time(NULL);
		tm* timeinfo = localtime(&seconds);
		fstream file(FILE_NAME, ios::app);
		file << asctime(timeinfo) << "Error: could not find file." << endl;
		file << asctime(timeinfo) << "Fatal_error: processes must be closed." << endl;
		file.close();
		cout << "Error: could not find file." << endl;
		cout << "Fatal_error: processes must be closed." << endl;
		break;
	}
	case LOG_FATAL_LEVEL:
	{
		time_t seconds = time(NULL);
		tm* timeinfo = localtime(&seconds);
		fstream file(FILE_NAME, ios::app);
		file << asctime(timeinfo) << "Fatal_error: processes must be closed." << endl;
		file.close();
		cout << "Fatal_error: processes must be closed." << endl;
		break;
	}
	}
}

#ifdef _MSC_VER

#define UP_EVENT 'U'
#define DOWN_EVENT 'D'
#define EXIT_EVENT 'E'
#define ACCESS_EVENT "A"

#else

void handler(int p)
{
	switch(p) 
	{
	case SIGINT:
	{
		exit(0);
	}
	case SIGHUP:
	{
		setLevel();
		cout << "getppid() = " << getppid() << endl;
		kill(getppid(), SIGHUP);
		return;
	}
	case SIGUSR1:
	{
		if (log_level < 2)
		{
			log_level++;
		}
		return;
	}	

	case SIGUSR2:
	{
		cout << "Log level down" << endl;
		if (log_level > 0)
		{
			log_level--;
		}
		return;
	}
	}
}	
#endif

int main(int argc, char * argv[])
{

#ifdef _MSC_VER

	HANDLE up_event;
	HANDLE down_event;
	HANDLE exit_event;
	HANDLE access_event;
	DWORD check;
	char buff[3];
	buff[0] = argv[0][0];
	buff[2] = '\0';

	buff[1] = UP_EVENT;
	if (!(up_event = OpenEventA(EVENT_ALL_ACCESS | EVENT_MODIFY_STATE, TRUE, buff)))
	{
		return 0;
	}

	buff[1] = DOWN_EVENT;
	if (!(down_event = OpenEventA(EVENT_ALL_ACCESS | EVENT_MODIFY_STATE, TRUE, buff)))
	{
		return 0;
	}

	buff[1] = EXIT_EVENT;
	if (!(exit_event = OpenEventA(EVENT_ALL_ACCESS | EVENT_MODIFY_STATE, TRUE, buff)))
	{
		return 0;
	}

	if (!(access_event = OpenEventA(EVENT_ALL_ACCESS | EVENT_MODIFY_STATE, TRUE, ACCESS_EVENT)))
	{
		return 0;
	}

	while (true)
	{
		check = WaitForSingleObject(up_event, NULL);
		if (check == WAIT_OBJECT_0)
		{
			if (log_level < 2){
				log_level++;
			}
		}

		check = WaitForSingleObject(down_event, NULL);
		if (check == WAIT_OBJECT_0)
		{
			if (log_level > 0){
				log_level--;
			}
		}

		check = WaitForSingleObject(exit_event, NULL);
		if (check == WAIT_OBJECT_0)
		{
			return 0;
		}

		check = WaitForSingleObject(access_event, INFINITY);
		if (check == WAIT_OBJECT_0) 
		{
			setLevel();
			SetEvent(access_event);
		}
		Sleep(4000);
	}

#else

	struct sigaction act;
	memset(&act, 0, sizeof(act));
	act.sa_handler = handler;
	sigset_t set;
	sigemptyset(&set);
	sigaddset(&set, SIGUSR1);
	sigaddset(&set, SIGUSR2);
	sigaddset(&set, SIGINT);
	sigaddset(&set, SIGHUP);
	act.sa_mask = set;
	sigaction(SIGUSR1, &act, NULL);
	sigaction(SIGUSR2, &act, NULL);
	sigaction(SIGINT, &act, NULL);
	sigaction(SIGHUP, &act, NULL);

#endif	

}