Linux--Socket套接字编程

在Linux环境下，使用socket进行编程主要涉及到客户端和服务器端。以下是一个简单的例子，展示了如何使用socket编程在Linux下创建TCP连接。

服务器端代码（server.c）:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
 
int main() {
    int server_fd, new_socket;
    struct sockaddr_in address;
    int addrlen = sizeof(address);
    char buffer[1024];
    int opt = 1;
    int client_sent;
 
    // 创建socket文件描述符
    if ((server_fd = socket(AF_INET, SOCK_STREAM, 0)) == 0) {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }
 
    // 绑定socket到地址和端口
    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");
        exit(EXIT_FAILURE);
    }
 
    // 监听socket
    if (listen(server_fd, 3) < 0) {
        perror("listen");
        exit(EXIT_FAILURE);
    }
 
    // 接受客户端连接
    if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&addrlen)) < 0) {
        perror("accept");
        exit(EXIT_FAILURE);
    }
 
    // 接收客户端消息
    while ((client_sent = recv(new_socket, buffer, 1024, 0)) > 0) {
        printf("Buffer: %s\n", buffer);
        // 发送消息回客户端
        if (send(new_socket, buffer, client_sent, 0) < 0) {
            perror("send");
        }
    }
 
    // 关闭socket
    close(new_socket);
    close(server_fd);
    return 0;
}

客户端代码（client.c）:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
 
int main(int argc, char *argv[]) {
    int sock;
    struct sockaddr_in serv_addr;
    char buffer[1024];
    int n;
 
    if (argc < 2) {
        printf("Please provide the server ip address as first argument\n");
        return 1;
    }
 
    // 创建socket
    if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        perror("socket failed");
        exit(EXIT_FAILURE);
    }
 
    // 设置服务器地址
    memset(&serv_addr, '0', sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(8080);
 
    if (inet_pton(AF_INET, argv[1], &serv_addr.sin_addr) <= 0) {
        perror("inet_pton error