比较两个路径所指内容是否相同

compare_file.cpp

#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <windows.h>
#include <fstream>
#include <cstring>
#include <cassert>

using namespace std;

#define BUFFER_SIZE 4096

//判断是否为dir
bool is_dir(const char *file_name)
{
	HANDLE hFile;
	WIN32_FIND_DATA FileInformation;
	hFile = ::FindFirstFile(file_name, &FileInformation);
	if (hFile != INVALID_HANDLE_VALUE)
	{
		::FindClose(hFile);
		if (FileInformation.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
		{
			return true;
		}
	}
	return false;
}

//判断文件是否存在
bool file_exist(const char *file_path)
{
	HANDLE hFile;
	WIN32_FIND_DATA FileInformation;
	hFile = ::FindFirstFile(file_path, &FileInformation);
	if (hFile != INVALID_HANDLE_VALUE)
	{
		::FindClose(hFile);
		return true;
	}
	return false;
}

//比较两个文件内容是否相同
//没有判断文件是否存在
bool file_compare(const char *src, const char *dest)
{
	//判断内容是否相同
	char src_buf[BUFFER_SIZE];
	char dest_buf[BUFFER_SIZE];
	fstream src_fs, dest_fs;
	int len;
	src_fs.open(src, ios_base::in);
	dest_fs.open(dest, ios_base::in);

	assert(src_fs.is_open());
	assert(dest_fs.is_open());
	while (true)
	{
		if (src_fs.eof() && dest_fs.eof())
		{
			src_fs.close();
			dest_fs.close();
			return true;
		}
		else if (src_fs.eof() || dest_fs.eof())
		{
			break;
		}

		src_fs.read(src_buf, BUFFER_SIZE);
		dest_fs.read(dest_buf, BUFFER_SIZE);

		if ((len = src_fs.gcount()) != dest_fs.gcount())
		{
			break;
		}
		if(memcmp(src_buf, dest_buf, len) != 0) break;
	}
	src_fs.close();
	dest_fs.close();
	return false;
}

//列出dir目录下的所有文件
//dir不能以\\结尾
void list_dir(const char *dir, vector<string> &fs)
{
	string strDir = dir;
	string strPattern;
	
	HANDLE hFile;
	WIN32_FIND_DATA FileInformation;

	strPattern = strDir + "\\*.*";
	hFile = ::FindFirstFile(strPattern.c_str(), &FileInformation);
	if (hFile != INVALID_HANDLE_VALUE)
	{
		do 
		{
			//去掉..和.目录
			if (FileInformation.cFileName[0] != '.')
			{
				fs.push_back(FileInformation.cFileName);
			}
		} while (::FindNextFile(hFile, &FileInformation) == TRUE);

		::FindClose(hFile);
	}
}

//比较两个文件或两个文件夹是否相同
//src和dest不能以\\结尾
bool diff(const char *src, const char *dest)
{
	string src_path = src;
	string dest_path = dest;

	//判断是否存在
	if (file_exist(src_path.c_str()) == false)
	{
#ifdef DEBUG
		cout << src_path << " no exist" << endl;
#endif
		return false;
	}

	if (file_exist(dest_path.c_str()) == false)
	{
#ifdef DEBUG
		cout << dest_path << " no exist" << endl;
#endif
		return false;
	}

	bool dir = is_dir(src_path.c_str());
	//是否同为dir或file
	if (dir == is_dir(dest_path.c_str()))
	{
		//同为dir
		if (dir)
		{
#ifdef DEBUG
			cout << "dir compare" << endl;
#endif
			vector<string> src_files, dest_files;
			//找到目录下所有文件，包括文件夹
			list_dir(src_path.c_str(), src_files);
			list_dir(dest_path.c_str(), dest_files);
			//按照字符串排序
			sort(src_files.begin(), src_files.end());
			sort(dest_files.begin(), dest_files.end());

			vector<string>::iterator src_it = src_files.begin();
			vector<string>::iterator dest_it = dest_files.begin();
			
			for (; src_it != src_files.end() && dest_it != dest_files.end(); src_it++, dest_it++)
			{
				//如果文件名不相同或文件内容不同，则返回false
#ifdef DEBUG
				cout << *src_it << " " << *dest_it << endl;
#endif
				if ((*src_it) != (*dest_it) || diff((src_path + "\\" + src_it->c_str()).c_str(), (dest_path + "\\" + dest_it->c_str()).c_str()) == false)
				{
					return false;
				}
			}
			//所有内容都相同，返回true
			if (src_it == src_files.end() && dest_it == dest_files.end())
			{
				return true;
			}
			return false;
		}
		else //同为file
		{
#ifdef DEBUG
			cout << "file compare" << endl;
#endif
			return file_compare(src_path.c_str(), dest_path.c_str());
		}
	}

#ifdef DEBUG
	else {

		cout << src_path << " and " << dest_path << " not the same type!" << endl;
	}
#endif
	return false;
}

int main(int argc, char *argv[])
{
	vector<string> fs;
	list_dir(".", fs);
	for (vector<string>::iterator it = fs.begin(); it != fs.end(); it++)
	{
		cout << *it << endl;
	}
	
	cout << file_compare("main.cpp", "main.cpp_cp") << endl;//1
	cout << diff("main.cpp", "main.cpp_cp") << endl;//1
	cout << diff("main.cpp", "not_main.cpp") << endl;//0

	cout << is_dir(".") << endl;//1
	cout << is_dir("..") << endl;//1
	cout << is_dir("main.cpp") << endl;//1
	cout << is_dir("nothing") << endl;//0

	cout << file_exist(".") << endl;//1
	cout << file_exist("nothing") << endl;//0

	cout << diff("dir", "dir_cp") << endl;//1
	cout << diff("dir", "not_dir") << endl;//0
	getchar();
	return 0;
}