FTP 编写 4：命令解析

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    我们知道在现实生活中使用的 FTP 是应答式的，客户端和服务端按照一定的规定进行交流，不是随便弄的，在上几篇中的 FTP 没有人机交互的功能。所以这篇文章的主要内容是按照平时 FTP 的交流规则重构一下整个工程的代码，并加入命令解析功能。

命令解析

    这部分命令解析只是简单模拟一下 FTP 的，在 FTP 的规则中还有应答返回值的规定，现在把它省略，简单定义一下服务端和客户端的交流规则

    现在的交流过程是这样的：在服务端和客户端启动以后，客户端向服务端发起连接，然后服务端向客户端发送一条欢迎信息；然后等待客户端发送相应的指令，根据指令进行答复和操作

//命令解析函数：将受到的命令进行分解，用字符分割函数分成指令和参数两部分int Client::commandParse(char * instruck, std::string & paramter){    std::string string(buf);    std::cout << string;    std::vector<std::string> command;    //以空格为分隔符进行分割    Tool::splitString(string, command, std::string(" "));    //判断传入的参数个数是否正确    if (command.size() != 2) {        paramter = "";        return -1;    }    //返回相应指令对应的数值    if (command[0] == "STOR") {        paramter = command[1];        return 1;    }    if (command[0] == "RETR") {        paramter = command[1];        return 2;    }    //默认返回错误指令    return 0;}//字符分割函数void Tool::splitString(const std::string & input, std::vector<std::string>& output, std::string &delim){    std::string::size_type pos1, pos2;    pos1 = 0;    pos2 = input.find(delim);    while (std::string::npos != pos2)    {        output.push_back(input.substr(pos1, pos2 - pos1));        pos1 = pos2 + delim.size();        pos2 = input.find(delim, pos1);    }    if (pos1 != input.length())        output.push_back(input.substr(pos1));}

服务端重构

    服务端的重构主要是将服务端运行的部分抽离出来写成一个类，类中包含了服务端的所有功能函数，并且在多线程中运行，服务端中的运行函数如下：

void Server::running(){    //与客户端进行连接以后就发送一个欢迎信息    welcome();    //然后进入无限循环，等待客户端的命令进行下一步操作    while (true) {        if (recv(server, buf, maxLen, 0) == 0) {            std::cout << "recv() Faied!\n";        }        std::string paramter;        int cmd = commandParse(buf, paramter);        switch (cmd) {        case 0:            std::cout << "Command is invalid\n";            break;        case 1:            std::cout << "Start receive the file from client.\n";            receiveFile(paramter);            break;        case 2:            std::cout << "Start send file to client.\n";            sendFile(paramter);            break;        default:            std::cout << "Command is invalid\n";        }    }}

客户端重构

    客户端也是将功能封装到一个类里面，但不需要多线程，运行函数如下：

void Client::running(){    memset(buf, 0, sizeof(buf));    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {        std::cout << "Failed to load Winsock\n";        system("pause");        return;    }    //char addr[20] = "113.54.167.16";    char addr[20] = "192.168.1.119";    //创建Socket    ser.sin_family = AF_INET;    ser.sin_port = htons(iPort);    inet_pton(AF_INET, addr, (void*)&ser.sin_addr.s_addr);    client = socket(AF_INET, SOCK_STREAM, 0);    if (client == INVALID_SOCKET) {        std::cout << "socket() Failed\n";        system("pause");        return;    }    //连接并进行简单的操作    if (connect(client, (struct sockaddr*)&ser, sizeof(ser)) == INVALID_SOCKET) {        std::cout << "connect() Failed\n";        system("pause");        return;    }    else {        //接收服务端发送的数据        iLen = recv(client, buf, sizeof(buf), 0);        if (iLen == 0) {            system("pause");            return;        }        else if (iLen == SOCKET_ERROR) {            std::cout << "recv() Failed\n";            system("pause");            return;        }        std::cout << "recv() data from server:" << buf << std::endl;    }    while (true) {        //输入相应的数据发送给服务端        std::cout << ">>";        std::cin.getline(buf, 1024);        std::string paramter;        int cmd = commandParse(buf, paramter);        switch (cmd) {        case 0:            std::cout << "Command is invalid\n";            break;        case 1:            std::cout << "Start receive the file from client.\n";            downloadFile(paramter);            break;        case 2:            std::cout << "Start send file to client.\n";            uploadFile(paramter);            break;        default:            std::cout << "Command is invalid\n";        }    }}

源代码

客户端

//main.cpp#pragma comment(lib,"ws2_32.lib")#include "Client.h"void main(){    Client client;    client.running();    system("pause");}//Client.h#pragma once#include <WinSock2.h>#include <string>class Client{public:    Client();    ~Client();    void running();    bool uploadFile(std::string file);    bool downloadFile(std::string file);    int commandParse(char* instruck, std::string &paramter);private:    SOCKET client;    char buf[1024];    //定义相应的数据    WSADATA wsaData;    int iPort = 5050;//对应的服务端的端口    int iLen, iSend;    struct sockaddr_in ser;};//Client.cpp#include "Client.h"#include "Tool.h"#include <iostream>#include <WS2tcpip.h>Client::Client(){}Client::~Client(){    //关闭连接并退出    closesocket(client);    //关闭 Winsock    WSACleanup();}void Client::running(){    memset(buf, 0, sizeof(buf));    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {        std::cout << "Failed to load Winsock\n";        system("pause");        return;    }    //char addr[20] = "113.54.167.16";    char addr[20] = "192.168.1.119";    //创建Socket    ser.sin_family = AF_INET;    ser.sin_port = htons(iPort);    inet_pton(AF_INET, addr, (void*)&ser.sin_addr.s_addr);    client = socket(AF_INET, SOCK_STREAM, 0);    if (client == INVALID_SOCKET) {        std::cout << "socket() Failed\n";        system("pause");        return;    }    //连接并进行简单的操作    if (connect(client, (struct sockaddr*)&ser, sizeof(ser)) == INVALID_SOCKET) {        std::cout << "connect() Failed\n";        system("pause");        return;    }    else {        //接收服务端发送的数据        iLen = recv(client, buf, sizeof(buf), 0);        if (iLen == 0) {            system("pause");            return;        }        else if (iLen == SOCKET_ERROR) {            std::cout << "recv() Failed\n";            system("pause");            return;        }        std::cout << "recv() data from server:" << buf << std::endl;    }    while (true) {        //输入相应的数据发送给服务端        std::cout << ">>";        std::cin.getline(buf, 1024);        std::string paramter;        int cmd = commandParse(buf, paramter);        switch (cmd) {        case 0:            std::cout << "Command is invalid\n";            break;        case 1:            std::cout << "Start receive the file from client.\n";            downloadFile(paramter);            break;        case 2:            std::cout << "Start send file to client.\n";            uploadFile(paramter);            break;        default:            std::cout << "Command is invalid\n";        }    }}bool Client::uploadFile(std::string file){    return false;}bool Client::downloadFile(std::string file){    return false;}int Client::commandParse(char * instruck, std::string & paramter){    std::string string(buf);    std::cout << string;    std::vector<std::string> command;    Tool::splitString(string, command, std::string(" "));    if (command.size() != 2) {        paramter = "";        return -1;    }    if (command[0] == "STOR") {        paramter = command[1];        return 1;    }    if (command[0] == "RETR") {        paramter = command[1];        return 2;    }    return 0;}

服务端

//main.cpp#include <Winsock2.h>#include <Ws2tcpip.h>#include <iostream>#include <thread>#include <vector>#pragma comment(lib,"ws2_32.lib")#include "Server.h"//多线程函数，创建的多线程运行此函数void server(SOCKET s);void main(){    //定义相关的数据    int iPort = 5050;//定义其端口    WSADATA wsaData;//Winsock 的启动参数    SOCKET sListen, sAccept;//套接口关键字,分别用于监听和接收连接    int iLen;    int iSend;    char buf[] = "I am a server";    struct sockaddr_in ser, cli;//网络地址    //定义多线程指针，用于创建线程    std::thread* t;    //用于线程的管理，保存创建的多线程指针，程序结束时释放占用的内存    std::vector<std::thread*> tManage;    Server* server = NULL;    std::cout << "----------------------------\n";    std::cout << "Server waitting\n";    std::cout << "----------------------------\n";    //启动winSocket    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {        std::cout << "Failed to load Winsock.\n";        return;    }    //创建Socket    sListen = socket(AF_INET, SOCK_STREAM, 0);    if (sListen == INVALID_SOCKET) {        std::cout << "socket() Failed:" << WSAGetLastError() <<"\n";        return;    }    //绑定IP地址    ser.sin_family = AF_INET;    ser.sin_port = htons(iPort);    ser.sin_addr.s_addr = htonl(INADDR_ANY);    if (bind(sListen, (LPSOCKADDR)&ser, sizeof(ser)) == SOCKET_ERROR) {        std::cout << "bind() Failed\n";        return;    }    //监听    if (listen(sListen, 5) == SOCKET_ERROR) {        std::cout << "listen() Failed\n";        return;    }    iLen = sizeof(cli);//获取客户端网络地址的长度    //接受连接和发送欢迎信息    //用循环使程序一直运行    while (true) {        //接收连接        sAccept = accept(sListen, (struct sockaddr*)&cli, &iLen);        if (sAccept == INVALID_SOCKET) {            std::cout << "accept() Failed\n";            break;        }        //创建新的线程，并加入容器中，并将线程后台运行        //t = new std::thread(server, sAccept);        //tManage.push_back(t);        //t->detach();        server = new Server(sAccept);        t = new std::thread(&Server::running, server);        tManage.push_back(t);        t->detach();    }    //释放指针占用的内存    for (int i = 0; i < tManage.size(); i++) {        delete(tManage[i]);    }    //关闭监听    closesocket(sListen);    //关闭 Winsock    WSACleanup();}//多线程函数，创建的多线程运行此函数void server(SOCKET s) {    SOCKET socket = s;    struct sockaddr_in ser, cli;//网络地址    int iSend, iRecv;    char buf[1024] = "I am a server";    //显示客户端的 IP 信息    char clibuf[20] = { '\0' };    inet_ntop(AF_INET, (void*)&cli.sin_addr, clibuf, 16);    std::cout << "Accept client IP:" << clibuf << ":" << ntohs(cli.sin_port) << std::endl;    //发送信息给客户端    iSend = send(socket, buf, sizeof(buf), 0);    if (iSend == SOCKET_ERROR) {        std::cout << "send() Failed\n";    }    else if (iSend == 0) {        std::cout << "send() Zero\n";    }    else {        std::cout << "Send byte:" << iSend << std::endl;        std::cout << "----------------------------------\n";    }    //使用循环不断接受客户端发送来的信息并显示    while (true) {        iRecv = recv(socket, buf, sizeof(buf), 0);        if (iRecv == 0) {            //std::cout << "recv() Zero\n";        }        else if (iRecv == SOCKET_ERROR) {            std::cout << "recv() Failed\n";        }        else {            std::cout << "recv() data from server:" << buf << std::endl;        }    }}//Server.h#pragma once#include <Winsock2.h>#include <string>class Server{public:    Server(SOCKET s);    ~Server();    //欢迎函数    bool welcome();    //服务端运行函数    void running();    //命令解析函数    int commandParse(char* instruck, std::string &paramter);    //文件接收函数    bool receiveFile(std::string filename);    //文件发送    bool sendFile(std::string filename);private:    SOCKET server;    int maxLen;    char buf[1024];};//Server.cpp#include "Server.h"#include "Tool.h"#include <iostream>#include <vector>Server::Server(SOCKET s)    :server(s){    maxLen = 1024;}Server::~Server(){}bool Server::welcome(){    char welcome[1024] = "Welcome, my friend\n";    //发送信息给客户端    int iSend = send(server, welcome, sizeof(welcome), 0);    if (iSend == SOCKET_ERROR) {        std::cout << "send() Failed\n";        return false;    }    return true;}void Server::running(){    welcome();    while (true) {        if (recv(server, buf, maxLen, 0) == 0) {            std::cout << "recv() Faied!\n";        }        std::string paramter;        int cmd = commandParse(buf, paramter);        switch (cmd) {        case 0:            std::cout << "Command is invalid\n";            break;        case 1:            std::cout << "Start receive the file from client.\n";            receiveFile(paramter);            break;        case 2:            std::cout << "Start send file to client.\n";            sendFile(paramter);            break;        default:            std::cout << "Command is invalid\n";        }    }}int Server::commandParse(char* instruck, std::string &paramter){    std::string string(buf);    std::cout << string;    std::vector<std::string> command;    Tool::splitString(string, command, std::string(" "));    //std::cout << command[0] << " " << command[1] << std::endl;    if (command.size() != 2) {        paramter = "";        return -1;    }    if (command[0] == "STOR") {        paramter = command[1];        return 1;    }    if (command[0] == "RETR") {        paramter = command[1];        return 2;    }    return -1;}bool Server::receiveFile(std::string filename){    return false;}bool Server::sendFile(std::string filename){    return false;}

工具类（字符分割方法，服务端与客户端完全一样)

//Tool.h#pragma once#include <string>#include <vector>class Tool{public:    Tool();    ~Tool();    //字符串分割函数    static void splitString(const std::string &input, std::vector<std::string> &output, std::string &delim);};//Tool.cpp#include "Tool.h"#include <sstream>#include <istream>Tool::Tool(){}Tool::~Tool(){}void Tool::splitString(const std::string & input, std::vector<std::string>& output, std::string &delim){    std::string::size_type pos1, pos2;    pos1 = 0;    pos2 = input.find(delim);    while (std::string::npos != pos2)    {        output.push_back(input.substr(pos1, pos2 - pos1));        pos1 = pos2 + delim.size();        pos2 = input.find(delim, pos1);    }    if (pos1 != input.length())        output.push_back(input.substr(pos1));}

源代码地址

https://github.com/lw1243925457/FTP