前言：

本文實現以下功能：

在客戶端，使用者選擇本地的某個檔案，併發送到伺服器端。
在伺服器端，接收客戶端傳輸的資料流，並按IP 地址儲存在伺服器端（文
件名重複的，可以覆蓋）。
如果傳輸過程中伺服器端發現客戶端斷開，伺服器端應刪除檔案，並在螢幕
上提示，如“IP：1.2.3.4 發來abcd.txt 檔案過程中失去連線。”。如果客戶端發
現伺服器端不工作，客戶端應有提示“伺服器1.2.3.5:62345 失去連線”。

一、Socket TCP傳輸的流程

二、程式碼實現

1.FileHelper用來進行與檔案相關的操作

#include<stdio.h>
#include<stdlib.h>
#include <WINSOCK2.H>
#include <STDIO.H>
#pragma  comment(lib,"ws2_32.lib")

class FileHelper
{
private:
	FILE *f;
	char path_buffer[_MAX_PATH];
	char drive[_MAX_DRIVE];
	char dir[_MAX_DIR];
	char fname[_MAX_FNAME];
	char ext[_MAX_EXT];

public:
	FILE * selectfile()
	{
		printf("請輸入要傳送的檔名\n");
		scanf("%s",path_buffer);

		if (f=fopen(path_buffer,"rb"))
		{
			printf("檔案開啟成功\n");
			return f;
		}
		else
		{
			printf("檔案不存在，請重新輸入\n");
			return selectfile();
		}
	}

	char * getFileName()
	{
		_splitpath(path_buffer, drive, dir, fname, ext);
		return strcat(fname, ext);
	}
	FILE * createFile(char *name)
	{
		remove(name);
		if (f = fopen(name, "ab"))
		{
			printf("檔案建立成功\n");

		}
		else
		{
			printf("檔案建立失敗\n");
		}
		return f;
	}

	bool createDir(char *dir)
	{
		char head[MAX_PATH] = "md ";
		return system(strcat(head, dir));
	}





};
 

#include <stdio.h>
#include <WINSOCK2.H>
#include <STDIO.H>
#include"FileHelper.h"
#pragma  comment(lib,"ws2_32.lib")


int main(int argc, char* argv[])
{
	WORD sockVersion = MAKEWORD(2,2);//版本號
	WSADATA data;    //用來儲存WSAStartup呼叫後返回的windows Sockets資料
	FileHelper fh;
	if(WSAStartup(sockVersion, &data) != 0)
	{
		return 0;
	}

	sockaddr_in serAddr;
	serAddr.sin_family = AF_INET;
	serAddr.sin_port = htons(8888);
	serAddr.sin_addr.S_un.S_addr = inet_addr("59.77.13.189"); 

	while (true)
	{
		SOCKET sclient = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
		if (sclient == INVALID_SOCKET)
		{
			printf("invalid socket !");
			return 0;
		}
		if (connect(sclient, (sockaddr *)&serAddr, sizeof(serAddr)) == SOCKET_ERROR)
		{
			printf("connect error !");
			closesocket(sclient);
			return 0;
		}
		FILE *f=fh.selectfile();
		char sendData[BUFSIZ];
		char recData[BUFSIZ];
		char over[BUFSIZ] = "Finnal";
		char * name = fh.getFileName();
		strcpy(sendData, name);
		printf("%s\n", sendData);
		int nCount;
		long long sum = 0;
		send(sclient, sendData, strlen(sendData)+1, 0);
		int ret = recv(sclient, recData, BUFSIZ, 0);
		printf(recData);
		while ((nCount=fread(sendData,1,BUFSIZ,f))>0)
		{
			printf("%db\n",sum+=nCount);
			
			send(sclient, sendData, nCount, 0);
			
			int ret = recv(sclient, recData, BUFSIZ, 0);
			if (ret >0)
			{
				
				//recData[ret] = 0x00;
				printf(recData);
			}
			else
			{
				printf("與伺服器失去連線");
				break;
			}
		}
		send(sclient, over, BUFSIZ, 0);
		ret = recv(sclient, recData, BUFSIZ, 0);
		if (ret>0&&strcmp(recData,over)==0)
		{
			printf("傳輸成功！");
		}
		fclose(f);
		closesocket(sclient);
	}
	WSACleanup();
	return 0;
}
 

#include <stdio.h>
#include <stdio.h>
#include <winsock2.h>
#include "FileHelper.h"
#pragma comment(lib,"ws2_32.lib")

int main(int argc, char* argv[])
{
	//初始化WSA
	WORD sockVersion = MAKEWORD(2, 2);
	WSADATA wsaData;
	FileHelper fh;
	if (WSAStartup(sockVersion, &wsaData) != 0)
	{
		return 0;
	}

	//建立套接字
	SOCKET slisten = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (slisten == INVALID_SOCKET)
	{
		printf("socket error !");
		return 0;
	}

	//繫結IP和埠
	sockaddr_in sin;
	sin.sin_family = AF_INET;
	sin.sin_port = htons(8888);
	sin.sin_addr.S_un.S_addr = INADDR_ANY;
	if (bind(slisten, (LPSOCKADDR)&sin, sizeof(sin)) == SOCKET_ERROR)
	{
		printf("bind error !");
	}

	//開始監聽
	if (listen(slisten, 5) == SOCKET_ERROR)
	{
		printf("listen error !");
		return 0;
	}

	//迴圈接收資料
	SOCKET sClient;
	sockaddr_in remoteAddr;
	int nAddrlen = sizeof(remoteAddr);
	char revData[BUFSIZ];
	while (true)
	{
		printf("等待連線...\n");
		sClient = accept(slisten, (SOCKADDR *)&remoteAddr, &nAddrlen);
		if (sClient == INVALID_SOCKET)
		{
			printf("accept error !");
			continue;
		}
		printf("接受到一個連線：%s \r\n", inet_ntoa(remoteAddr.sin_addr));
		/*if (fh.createDir(inet_ntoa(remoteAddr.sin_addr)))
			printf("資料夾建立成功！");*/
		int ret = 0;
		long long count = 0;
		char sendData[BUFSIZ] = "你好，TCP客戶端！\n";
		ret = recv(sClient, revData, BUFSIZ, 0);
		char fromname[BUFSIZ] = {};
		strcpy(fromname, revData);
		char mid[3] = "\\";
		char finame[MAX_PATH] = {};
		char over[BUFSIZ] = "Finnal";
		strcat(finame, inet_ntoa(remoteAddr.sin_addr));
		printf(finame);
		strcat(finame, mid);
		strcat(finame, revData);
		//printf(finame);
		FILE *f = fh.createFile(finame);
		send(sClient, sendData, BUFSIZ, 0);
		while ((ret = recv(sClient, revData, BUFSIZ, 0)) > 0)
		{
			//printf("%d\n", ret);
			printf("%db\n", count += ret);
			if (strcmp(revData,over)==0)
			{
				printf("檔案%s傳輸成功\n", fromname);
				break;
				send(sClient, over, BUFSIZ, 0);
			}
			fwrite(revData, 1, ret, f);
			send(sClient, sendData, BUFSIZ, 0);
		}
		fclose(f);
		if (strcmp(revData, over) != 0)
		{
			printf("IP：%s發來的%s傳輸過程中失去連線\n", inet_ntoa(remoteAddr.sin_addr),fromname);
			remove(finame);
		}




		closesocket(sClient);
	}

	closesocket(slisten);
	WSACleanup();
	return 0;
}