linux使用socket

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>

int main() {
    int sockfd;
    struct sockaddr_in server_addr;

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

    // 设置服务器地址
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(8080);
    inet_pton(AF_INET, "127.0.0.1", &server_addr.sin_addr);

    // 连接服务器
    if (connect(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {
        perror("connect");
        close(sockfd);
        exit(EXIT_FAILURE);
    }

    // 发送数据
    char *message = "Hello, Server!";
    send(sockfd, message, strlen(message), 0);

    // 接收数据
    char buffer[1024];
    int bytes_received = recv(sockfd, buffer, sizeof(buffer) - 1, 0);
    buffer[bytes_received] = '\0';
    printf("Received: %s\n", buffer);

    // 关闭 socket
    close(sockfd);
    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>

int main() {
    int server_fd, new_socket;
    struct sockaddr_in address;
    int addrlen = sizeof(address);

    // 创建 socket
    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }

    // 绑定 socket
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(8080);

    if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {
        perror("bind failed");
        close(server_fd);
        exit(EXIT_FAILURE);
    }

    // 监听连接
    if (listen(server_fd, 3) < 0) {
        perror("listen");
        close(server_fd);
        exit(EXIT_FAILURE);
    }

    // 接受连接
    if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&addrlen)) < 0) {
        perror("accept");
        close(server_fd);
        exit(EXIT_FAILURE);
    }

    // 接收数据
    char buffer[1024] = {0};
    int bytes_received = recv(new_socket, buffer, sizeof(buffer), 0);
    printf("Received: %s\n", buffer);

    // 发送数据
    char *response = "Hello, Client!";
    send(new_socket, response, strlen(response), 0);

    // 关闭 socket
    close(new_socket);
    close(server_fd);
    return 0;
}

struct timeval timeout;
timeout.tv_sec = 5;  // 5秒超时
timeout.tv_usec = 0;
setsockopt(sockfd, SOL_SOCKET, SO_SNDTIMEO, (char *)&timeout, sizeof(timeout));
setsockopt(sockfd, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout, sizeof(timeout));

server_addr.sin_port = htons(8081);  // 更改端口号