log文件的读写[转]

/**  
 * 用于输出log文件的类.  
 */    


#ifndef LOG_H    
#define LOG_H    


//log文件路径  
#define LOG_FILE_NAME "log.txt"  

//启用开关  
#define LOG_ENABLE  

#include <fstream>    
#include <string>    
#include <ctime>    

using namespace std;    

class CLog    
{    
public:    
    static void GetLogFilePath(CHAR* szPath)  
    {  
        GetModuleFileNameA( NULL, szPath, MAX_PATH ) ;  
        ZeroMemory(strrchr(szPath,_T('\\')), strlen(strrchr(szPath,_T('\\') ) )*sizeof(CHAR)) ;  
        strcat(szPath,"\\");  
        strcat(szPath,LOG_FILE_NAME);  
    }  
    //输出一个内容，可以是字符串(ascii)、整数、浮点数、布尔、枚举  
    //格式为：[2011-11-11 11:11:11] aaaaaaa并换行  
    template <class T>  
    static void WriteLog(T x)  
    {  
        CHAR szPath[MAX_PATH] = {0};  
        GetLogFilePath(szPath);  

        ofstream fout(szPath,ios::app);  
        fout.seekp(ios::end);  
        fout << GetSystemTime() << x <<endl;  
        fout.close();  
    }  

    //输出2个内容，以等号连接。一般用于前面是一个变量的描述字符串，后面接这个变量的值  
    template<class T1,class T2>   
    static void WriteLog2(T1 x1,T2 x2)  
    {  
        CHAR szPath[MAX_PATH] = {0};  
        GetLogFilePath(szPath);  
        ofstream fout(szPath,ios::app);  
        fout.seekp(ios::end);  
        fout << GetSystemTime() << x1 <<" = "<<x2<<endl;  
        fout.close();  
    }  

    //输出一行当前函数开始的标志,宏传入__FUNCTION__  
    template <class T>  
    static void WriteFuncBegin(T x)  
    {  
        CHAR szPath[MAX_PATH] = {0};  
        GetLogFilePath(szPath);  
        ofstream fout(szPath,ios::app);  
        fout.seekp(ios::end);  
        fout << GetSystemTime() << "    --------------------"<<x<<"  Begin--------------------" <<endl;  
        fout.close();  
    }  

    //输出一行当前函数结束的标志，宏传入__FUNCTION__  
    template <class T>  
    static void WriteFuncEnd(T x)  
    {  
        CHAR szPath[MAX_PATH] = {0};  
        GetLogFilePath(szPath);  
        ofstream fout(szPath,ios::app);  
        fout.seekp(ios::end);  
        fout << GetSystemTime() << "--------------------"<<x<<"  End  --------------------" <<endl;  
        fout.close();  
    }  


private:  
    //获取本地时间，格式如"[2011-11-11 11:11:11] ";   
    static string GetSystemTime()    
    {    
        time_t tNowTime;    
        time(&tNowTime);    
        tm* tLocalTime = localtime(&tNowTime);    
        char szTime[30] = {'\0'};    
        strftime(szTime, 30, "[%Y-%m-%d %H:%M:%S] ", tLocalTime);    
        string strTime = szTime;    
        return strTime;    
    }    

};    

#ifdef LOG_ENABLE  

//用下面这些宏来使用本文件  
#define LOG(x)              CLog::WriteLog(x);          //括号内可以是字符串(ascii)、整数、浮点数、bool等  
#define LOG2(x1,x2)     CLog::WriteLog2(x1,x2);  
#define LOG_FUNC        LOG(__FUNCTION__)               //输出当前所在函数名  
#define LOG_LINE        LOG(__LINE__)                       //输出当前行号  
#define LOG_FUNC_BEGIN  CLog::WriteFuncBegin(__FUNCTION__);     //形式如：[时间]"------------FuncName  Begin------------"  
#define LOG_FUNC_END     CLog::WriteFuncEnd(__FUNCTION__);      //形式如：[时间]"------------FuncName  End------------"  

#else  

#define LOG(x)                
#define LOG2(x1,x2)       
#define LOG_FUNC          
#define LOG_LINE          
#define LOG_FUNC_BEGIN    
#define LOG_FUNC_END      

#endif  

#endif