编辑“︁C 语言网络编程基础”︁（章节）

=== 服务器端流程 ===
1. 绑定地址：<code>bind()</code>
2. 监听连接：<code>listen()</code>
3. 接受连接：<code>accept()</code>

示例服务器代码：
<syntaxhighlight lang="c">
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>

#define PORT 8080
#define BACKLOG 5

int main() {
    int server_fd, new_socket;
    struct sockaddr_in address;
    int opt = 1;
    int addrlen = sizeof(address);
    
    // 创建套接字
    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }
    
    // 设置套接字选项
    if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt))) {
        perror("setsockopt");
        exit(EXIT_FAILURE);
    }
    
    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(PORT);
    
    // 绑定
    if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {
        perror("bind failed");
        exit(EXIT_FAILURE);
    }
    
    // 监听
    if (listen(server_fd, BACKLOG) < 0) {
        perror("listen");
        exit(EXIT_FAILURE);
    }
    
    printf("Server listening on port %d\n", PORT);
    
    // 接受连接
    if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&addrlen)) < 0) {
        perror("accept");
        exit(EXIT_FAILURE);
    }
    
    char buffer[1024] = {0};
    read(new_socket, buffer, 1024);
    printf("Message from client: %s\n", buffer);
    
    char *hello = "Hello from server";
    send(new_socket, hello, strlen(hello), 0);
    
    close(new_socket);
    close(server_fd);
    return 0;
}
</syntaxhighlight>