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EventLogger Class

Class programmed in C++ to log events & errors utilizing the C++ Standard Library.

Submitted By: DangerD

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Rating:

Views: 92

Language: C++

Last Modified: November 9, 2009

Instructions: I know there is alot of room for improvement... If you see ways to better my code or have any criticisms please post them. I was programming this class using wstrings to support UNICODE and when I got to printing to the file with wofstream there seems to be some kind of bug. Long story short the logging part is just regular old string and fstream.

Simple example for it's usage...

CODE

#include <windows.h>
#include "EventLogger.h"
EventLogger Log;

BOOL WINAPI DllMain(
HANDLE hinstDLL,
DWORD dwReason,
LPVOID lpvReserved
)
{
if(dwReason == DLL_PROCESS_ATTACH)
{
// initialize things we need for logging
// get the our dll's path
Log.FindFilePath(hinstDLL);
// replace the dll file name with log file name
Log.ReplaceFileName(Log.FilePath(), _T("EventLog.txt"));
// Open File for writing...
Log.OpenFile(Log.FilePath());
// write to the log!
Log.LogEvent("Attached to process!");
}

return 0;
}

Snippet

[code]
//////////////////////////////////////////////////////////////////////////
// EventLog Class
// by DangerD (DangerD@live.com)
//////////////////////////////////////////////////////////////////////////
// EventLog.h
#ifndef EVENTLOGGER_H
#define EVENTLOGGER_H
#include <string>
#include <fstream>
class EventLogger
{
public:
EventLogger(); // constructor
~EventLogger(); // ~destructor
std::wstring FilePath();
bool FindFilePath(HMODULE hModule);
void ReplaceFileExt(std::wstring& FilePath,
const std::wstring& NewExt);
void ReplaceFileName(std::wstring& FilePath,
const std::wstring& NewName);
bool OpenFile(const std::wstring& FilePath);
std::string GetTime();
void LogEvent(const std::string& Event);
private:
std::wstring m_FilePath;
std::string m_Time;
std::ofstream m_File;
};
#endif
// end of file
//////////////////////////////////////////////////////////////////////////
[/code]
[code]
//////////////////////////////////////////////////////////////////////////
// EventLog Class
// by DangerD (DangerD@live.com)
//////////////////////////////////////////////////////////////////////////
// EventLog.cpp
#include <Windows.h>
#include <tchar.h>
#include <time.h>
//---
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
//---
#include "EventLogger.h"
// constructor
EventLogger::EventLogger()
{
}
// ~destructor
EventLogger::~EventLogger()
{
m_File.close();
}
std::wstring EventLogger::FilePath()
{
return m_FilePath;
}
bool EventLogger::FindFilePath(HMODULE hModule)
{
std::vector<TCHAR> Path(MAX_PATH);
if(!GetModuleFileName(hModule, &Path[0], Path.size())) {
// you can change this for however your program handles errors
std::wcerr << _T("Error: Couldn't get file path.") << std::endl;
return false;
}
m_FilePath = &Path[0];
return true;
}
void EventLogger::ReplaceFileExt(std::wstring& FilePath,
const std::wstring& NewExt)
{
int Length = FilePath.length();
int FileExt = Length - 4;
FilePath.replace(FileExt, Length, NewExt);
m_FilePath = FilePath;
}
void EventLogger::ReplaceFileName(std::wstring& FilePath,
const std::wstring& NewName)
{
int Pos = FilePath.rfind(_T("\\")); ++Pos;
FilePath.erase(Pos, std::string::npos);
FilePath.append(NewName);
m_FilePath = FilePath;
}
bool EventLogger::OpenFile(const std::wstring& FilePath)
{
m_File.open(FilePath.c_str(), std::ios::out | std::ios::app);
if (!m_File) {
// you can change this for however your program handles errors
std::wcerr << _T("Error: Couldn't open file!") << std::endl;
return false;
}
return true;
}
std::string EventLogger::GetTime()
{
time_t rawtime;
struct tm timeinfo;
std::vector<char> Time(MAX_PATH);
time(&rawtime);
localtime_s(&timeinfo, &rawtime);
strftime(&Time[0], Time.size(),"%I:%M%p-> ", &timeinfo);
m_Time = &Time[0];
return m_Time;
}
void EventLogger::LogEvent(const std::string& Event)
{
GetTime();
m_File << m_Time << Event << std::endl;
}
// end of file
//////////////////////////////////////////////////////////////////////////
[/code]

Copy & Paste

[code]
//////////////////////////////////////////////////////////////////////////
// EventLog Class
// by DangerD (DangerD@live.com)
//////////////////////////////////////////////////////////////////////////
// EventLog.h

#ifndef EVENTLOGGER_H
#define EVENTLOGGER_H

#include <string>
#include <fstream>

class EventLogger
{
public:
	EventLogger();		// constructor
	~EventLogger();	// ~destructor
	std::wstring FilePath();
	bool FindFilePath(HMODULE hModule);
	void ReplaceFileExt(std::wstring& FilePath, 
		const std::wstring& NewExt);
	void ReplaceFileName(std::wstring& FilePath,
		const std::wstring& NewName);
	bool OpenFile(const std::wstring& FilePath);
	std::string GetTime();
	void LogEvent(const std::string& Event);

private:
	std::wstring m_FilePath;
	std::string m_Time;
	std::ofstream m_File;
};

#endif

// end of file
//////////////////////////////////////////////////////////////////////////
[/code]
[code]
//////////////////////////////////////////////////////////////////////////
// EventLog Class
// by DangerD (DangerD@live.com)
//////////////////////////////////////////////////////////////////////////
// EventLog.cpp

#include <Windows.h>
#include <tchar.h>
#include <time.h>
//---
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
//---
#include "EventLogger.h"

// constructor
EventLogger::EventLogger()
{

}

// ~destructor
EventLogger::~EventLogger()
{
	m_File.close();
}

std::wstring EventLogger::FilePath()
{
	return m_FilePath;
}

bool EventLogger::FindFilePath(HMODULE hModule)
{
	std::vector<TCHAR> Path(MAX_PATH);
	if(!GetModuleFileName(hModule, &Path[0], Path.size())) {
		// you can change this for however your program handles errors
		std::wcerr << _T("Error: Couldn't get file path.") << std::endl;
		return false;
	}
	m_FilePath = &Path[0];
	return true;
}

void EventLogger::ReplaceFileExt(std::wstring& FilePath, 
							  const std::wstring& NewExt)
{
	int Length = FilePath.length();
	int FileExt = Length - 4;
	FilePath.replace(FileExt, Length, NewExt);
	m_FilePath = FilePath;
}

void EventLogger::ReplaceFileName(std::wstring& FilePath, 
							   const std::wstring& NewName)
{
	int Pos = FilePath.rfind(_T("\\")); ++Pos;
	FilePath.erase(Pos, std::string::npos);
	FilePath.append(NewName);
	m_FilePath = FilePath;
}

bool EventLogger::OpenFile(const std::wstring& FilePath)
{
	m_File.open(FilePath.c_str(), std::ios::out | std::ios::app);
	if (!m_File) {
		// you can change this for however your program handles errors
		std::wcerr << _T("Error: Couldn't open file!") << std::endl;
		return false;
	}
	return true;
}

std::string EventLogger::GetTime()
{
	time_t rawtime;
	struct tm timeinfo;
	std::vector<char> Time(MAX_PATH);
	time(&rawtime);
	localtime_s(&timeinfo, &rawtime);
	strftime(&Time[0], Time.size(),"%I:%M%p-> ", &timeinfo);
	m_Time = &Time[0];
	return m_Time;
}

void EventLogger::LogEvent(const std::string& Event)
{
	GetTime();
	m_File << m_Time << Event << std::endl;
}

// end of file
//////////////////////////////////////////////////////////////////////////
[/code]