socket实验报告

实验名称：使用socket实现TCP/IP通信

实验目的：通过本次实验，掌握socket编程的基本知识，了解TCP/IP通信的原理和实现方式。

实验环境：Ubuntu 18.04

实验步骤：

1. 编写服务器端程序

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#define PORT 12345

int main(void)
{
    int server_sockfd, client_sockfd;
    struct sockaddr_in server_addr, client_addr;
    socklen_t client_addr_len;
    char buf[1024];

    if ((server_sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(PORT);
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);

    if (bind(server_sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {
        perror("bind");
        exit(EXIT_FAILURE);
    }

    if (listen(server_sockfd, 5) == -1) {
        perror("listen");
        exit(EXIT_FAILURE);
    }

    printf("server is listening...\n");

    client_addr_len = sizeof(client_addr);
    if ((client_sockfd = accept(server_sockfd, (struct sockaddr *)&client_addr, &client_addr_len)) == -1) {
        perror("accept");
        exit(EXIT_FAILURE);
    }

    printf("client %s is connected\n", inet_ntoa(client_addr.sin_addr));

    while (1) {
        memset(buf, 0, sizeof(buf));
        if (recv(client_sockfd, buf, sizeof(buf), 0) == -1) {
            perror("recv");
            exit(EXIT_FAILURE);
        }

        printf("recv data: %s\n", buf);

        if (send(client_sockfd, buf, sizeof(buf), 0) == -1) {
            perror("send");
            exit(EXIT_FAILURE);
        }
    }

    close(client_sockfd);
    close(server_sockfd);

    return 0;
}

2. 编译服务器端程序

$ gcc server.c -o server

3. 运行服务器端程序

$ ./server

4. 编写客户端程序

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#define PORT 12345

int main(int argc, char *argv[])
{
    int sockfd;
    struct sockaddr_in server_addr;
    char buf[1024];

    if (argc != 2) {
        fprintf(stderr, "usage: %s <ip_address>\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(PORT);
    server_addr.sin_addr.s_addr = inet_addr(argv[1]);

    if (connect(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {
        perror("connect");
        exit(EXIT_FAILURE);
    }

    printf("connected to server %s\n", inet_ntoa(server_addr.sin_addr));

    while (1) {
        printf("input data: ");
        fgets(buf, sizeof(buf), stdin);

        if (send(sockfd, buf, sizeof(buf), 0) == -1) {
            perror("send");
            exit(EXIT_FAILURE);
        }

        memset(buf, 0, sizeof(buf));
        if (recv(sockfd, buf, sizeof(buf), 0) == -1) {
            perror("recv");
            exit(EXIT_FAILURE);
        }

        printf("recv data: %s\n", buf);
    }

    close(sockfd);

    return 0;
}

5. 编译客户端程序

$ gcc client.c -o client

6. 运行客户端程序

$ ./client 127.0.0.1

实验结果：

在客户端输入数据后，服务端能够接收到数据并输出，同时将数据原封不动地发送回客户端。客户端接收到服务端发送的数据后，也能够正确输出。说明TCP/IP通信已经成功建立。

实验总结：

本次实验通过socket编程，实现了TCP/IP通信。socket编程是网络编程的基础，掌握socket编程的基本知识对于理解网络编程非常重要。通过本次实验，我不仅深入了解了TCP/IP通信的原理和实现方式，还锻炼了代码编写能力。