一个用于读取应用程序配置文件（*.ini）的类

应用程序往往都有一个配置文件，在windows下，一般采用*.ini文件的方式，我们需要调用windows api来读取配置文件，api使用起来繁琐，笔者自己开发了一个读配置文件的类，使用十分方便，在使用的时候只需要实现具体的一个虚函数即可。

#pragma once

#include "string"
#include "iostream"

using namespace std;

#define BLANK  32


class CFiletovariable
{
public:
	CFiletovariable(void);
	CFiletovariable(string filename);
	~CFiletovariable(void);
private:
	string filename;
public:
	void readcfg();
private:
	long getfilesize();
	void process(string & buff);
	void subprocess(string & buff);
	void trimspace(string & buff);
	void deletecomment(string & buff);
	void deleteblankrow(string & buff);
	int countpart(string sour, string part[], char flag);	
protected:
	virtual void insert(string section, string key, string value);
};


#include "Filetovariable.h"


CFiletovariable::CFiletovariable(void)
{
}


CFiletovariable::CFiletovariable(string filename)
{
	this->filename = filename;
}

CFiletovariable::~CFiletovariable(void)
{
}

void CFiletovariable::readcfg()
{
	long size = getfilesize();
	FILE *fp = NULL; 
	int err = fopen_s(&fp, filename.c_str(), "rt");

	if (err != 0) 
	{
		cout<<"file is not existed, please check where the configuration file is"<<endl;
		return;
	}	
	
	char *pbuff = new char[size];
	memset(pbuff, 0, size);
	fread(pbuff, size, 1, fp);
	string content(pbuff);
	delete []pbuff;

	process(content);
	
	fclose(fp);
}


long CFiletovariable::getfilesize()
{  
	long  size = 0;  
	FILE  *fp = NULL;

	int err = fopen_s(&fp, filename.c_str(), "rt");  

	if (err != 0) 
	{
		cout<<"file is not existed, please check where the configuration file is"<<endl;
		return size;
	}

	fseek(fp, 0, SEEK_END);  
	size = ftell(fp);    
	fclose(fp);  

	return size;
}

void CFiletovariable::trimspace(string & buff)
{
	int pos = buff.find(BLANK, 0);
	while(pos != string::npos)
	{
		buff.erase(pos, 1);
		pos = buff.find(BLANK, pos);
	}
}

void CFiletovariable::deletecomment(string & buff)
{
	int pos1 = buff.find(';', 0);
	while(pos1 != string::npos)
	{
		int pos2 = buff.find('\n\r', pos1 + 1);
		buff.erase(pos1, pos2 - pos1 + 1);
		pos1 = buff.find(';', 0);
	}
}

void CFiletovariable::deleteblankrow(string & buff)
{
	int pos1 = buff.find('\n\r', 0);
	while(pos1 != string::npos)
	{
		int pos2 = buff.find('\n\r', pos1 + 1);
		if (pos2 - pos1 == 1)
		{
			buff.erase(pos1, pos2 - pos1);
		}
		pos1 = buff.find('\n\r', pos2);
	}
}

void CFiletovariable::process(string & buff)
{  		
	string section;
	int count = 0;
	trimspace(buff);
	deletecomment(buff);
	deleteblankrow(buff);

	printf("%s\n", buff.c_str());

	int pos1 = buff.find('[', 0);
	int pos2 = buff.find('[', pos1 + 1);
	while(pos2 != string::npos)
	{	
		section = buff.substr(pos1, pos2 - pos1);
		subprocess(section);
		pos1 = pos2;
		pos2 = buff.find('[', pos1 + 1);
	}
	section = buff.substr(pos1, buff.size() - pos1);
	subprocess(section);
	return;
}

void CFiletovariable::subprocess(string& buff)
{
	int pos1 = buff.find('[', 0);
	int pos2 = buff.find(']', 0);
	string section = buff.substr(pos1 + 1, pos2 - pos1 - 1);

	pos1 = buff.find('\n\r', 0);
	pos2 = buff.find('\n\r', pos1 + 1);

	while(pos2 != string::npos)
	{
		string keyandvalue = buff.substr(pos1 + 1, pos2 - pos1 - 1);
		string part[2];
		int count = countpart(keyandvalue, part, '=');
		if (count == 2)
		{
			insert(section, part[0], part[1]);
		}
		pos1 = pos2;
		pos2 = buff.find('\n\r', pos1 + 1);
	}
}



int CFiletovariable::countpart(string sour, string part[], char flag)
{
	int count = 0;	
	int pos1 = 0;
	int pos2 = sour.find(flag, pos1);
	while(pos2 != string::npos)
	{
		part[count] = sour.substr(pos1, pos2 - pos1);
		pos1 = pos2 + 1;
		pos2 = sour.find(flag, pos1);
		count++;
	}
	part[count] = sour.substr(pos1, sour.length() - pos1);
	count++;
	return count;
}

void CFiletovariable::insert(string section, string key, string value)
{
}

下边是主函数测试：

// readcfg.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "filetovariable.h"

using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
	CFiletovariable ftovari("D:\\C++\\readcfg\\Debug\\test.txt");
	ftovari.readcfg();	
	system("pause");
	return 0;
}