C++网络编程系列之2：One-loop per connection

Bertha 。 2022-12-12 04:57 48阅读 0赞

往期相关文章：

*  [TCP套接字编程（C语言）][TCP_C]

linux C++网络编程系列之2：单线程阻塞模式，这是最基础最简单的服务器代码，用途不大，但这是网络编程的基础。

## 服务端代码 ##

/*
     * Cpp server version 0: One-loop per connection.
     */
    
    #include <iostream>
    #include <string.h>
    #include <functional>
    #include <sys/socket.h>
    #include <sys/types.h>
    #include <netinet/in.h>
    #include <unistd.h>
    #include <arpa/inet.h>
    using namespace std;
    
    void reverse_string(char* origin_str, char* target_str, int max_len = 255) {
        
        if (origin_str == nullptr || '\0' == *origin_str) {
        
            target_str[0] = '\0';
            return ;
        }
    
        int str_len = 0;
        char* lptr = origin_str;
        char* rptr = origin_str;
        while (*rptr != '\0' && str_len++ < max_len) {
        
            rptr++;
        }
    
        rptr--;
        while (lptr < rptr) {
        
            char tmp = *lptr;
            *lptr = *rptr;
            *rptr = tmp;
            lptr++;
            rptr--;
        }
    
        strcpy(target_str, origin_str);
    }
    
    void process_func(std::function<void (char*, char*, int)> fn, char* recv_buf, char* send_buf) {
        
        fn(recv_buf, send_buf, 255);
    }
    
    int main() {
        
        int socket_server = socket(AF_INET, SOCK_STREAM, 0);
        if (socket_server == -1) {
        
            cout << "Error 001: create server socket failed." << endl;
            return -1;
        }
    
        struct sockaddr_in addr;
        addr.sin_family = AF_INET;
        addr.sin_port = htons(8000);
        addr.sin_addr.s_addr = INADDR_ANY;
        if (bind(socket_server, (struct sockaddr*)&addr, sizeof(addr)) == -1) {
        
            cout << "Error 002: bind failed." << endl;
            return -1;
        }
    
        if (listen(socket_server, 5) == -1) {
        
            cout << "Error 003: listen failed." << endl;
            return -1;
        }
    
        int conn;
        std::function<void (char*, char*, int)> func = reverse_string;
        struct sockaddr_in client_addr;
        socklen_t client_addr_len = sizeof(client_addr);
        while (true) {
        
            cout << "Waiting for new connection..." << endl;
            conn = accept(socket_server, (struct sockaddr*)&client_addr, &client_addr_len);
            if (conn < 0) {
        
                cout << "Error 101: accept failed." << endl;
                return -1;
            }
    
            char recv_buf[255];
            char send_buf[255];
            while (true) {
        
                memset(recv_buf, 0, sizeof(recv_buf));
                int recv_len = recv(conn, recv_buf, sizeof(recv_buf), 0);
                recv_buf[recv_len] = '\0';
                if (strcmp(recv_buf, "exit") == 0) {
        
                    cout << "Exit: client exit." << endl;
                    break;
                }
                cout << "[Client] " << recv_buf << endl;
    
                process_func(func, recv_buf, send_buf);
                cout << "[Server] " << send_buf << endl;
                send(conn, send_buf, sizeof(send_buf), 0);
            }
    
            close(conn);
        }
    }

## 客户端代码 ##

#include <iostream>
    #include <sstream>
    #include <string.h>
    #include <sys/socket.h>
    #include <netinet/in.h>
    #include <unistd.h>
    #include <arpa/inet.h>
    using namespace std;
    
    int main() {
        
        int client = socket(AF_INET, SOCK_STREAM, 0);
        if (client == -1) {
        
            cout << "Error 401: create client socket failed." << endl;
            return -1;
        }
    
        struct sockaddr_in server_addr;
        server_addr.sin_family = AF_INET;
        server_addr.sin_port = htons(8000);
        server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
        if (connect(client, (struct sockaddr*)&server_addr, sizeof(server_addr)) < 0) {
        
            cout << "Error 402: connect failed." << endl;
            return -1;
        }
    
        cout << "Success: connected to server." << endl;
    
        char send_buf[255];
        char recv_buf[255];
        while (cin.getline(send_buf, 255)) {
        
            send(client, send_buf, strlen(send_buf), 0);
            if (strcmp(send_buf, "exit") == 0) {
        
                cout << "Exit: disconnecting with server." << endl;
                break;
            }
    
            memset(recv_buf, 0, sizeof(recv_buf));
            int recv_len = recv(client, recv_buf, sizeof(recv_buf), 0);
            recv_buf[recv_len] = '\0';
            cout << "[Server]: " << recv_buf << endl;
        }
    
        close(client);
    }

[TCP_C]: https://blog.csdn.net/qq_26822029/article/details/80511334