该类的作用是写入程序运行时的错误.

/******************头文件***************************/
#ifndef LOG_H
#define LOG_H
#include <stdio.h>
#include <stdarg.h>
class LOG
{
protected:
    FILE * logfile;
   
    bool Shutdown(void);
public:
    bool Init(char * filename);

    //output to log
    void OutputNewline();
    void OutputError(char * text, ...);
    void OutputSuccess(char * text, ...);
   
    LOG() {}
    ~LOG() { Shutdown(); }
};
#endif

/************实现文件*******************/

#include "LOG.h"

//initiates logfile
bool LOG::Init(char * filename)
{
    if( (logfile = fopen(filename, "wb")) == NULL)
        return false;
    fclose(logfile);
    return true;
}

//shuts down log
bool LOG::Shutdown()
{
    if(logfile)
        fclose(logfile);
    return true;
}

//
void LOG::OutputNewline()
{
    if( (logfile = fopen("Error Log.txt", "a+")) == NULL )
        return;
    putc('\n', logfile);
    fclose(logfile);
}

void LOG::OutputError(char * text, ...)
{
    va_list arg_list;
   
    va_start(arg_list, text);
    if( (logfile = fopen("Error Log.txt", "a+")) == NULL )
        return;
    //写入文件
    fprintf(logfile, "<!>");
    vfprintf(logfile, text, arg_list);
    putc('\n', logfile);
    //写到console
    printf("<!>");
    vprintf(text, arg_list);
    printf("\n");
   
    fclose(logfile);
    va_end(arg_list);
   
}