单进程服务器

code

使用方法

./run.sh

客户端 client

/*
 * @Author: sjhuang
 * @Date: 2022-03-05 16:35:32
 * @LastEditTime: 2022-03-11 12:40:42
 * @FilePath: /computer_network/src/socket_c/single_socket_c/client.c
 */
#include "single_socket.h"

int main(){
errno = 0;
char buf[60];
// 创建套接字
int fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
struct sockaddr_in serv_addr;
// 客户端也可以调用 bind 来指定端口号，而不是内核随机分配
// 指定端口号，
// struct sockaddr_in cli_addr;
// 初始化 cli_addr
//    memset(&cli_addr, 0, sizeof(serv_addr));
//    // 指定端口
//    cli_addr.sin_port = htons(6666);
//    bind(fd, (struct sockaddr *)(&cli_addr), sizeof(cli_addr));

// 初始化 server_addr
memset(&serv_addr, 0, sizeof(serv_addr));
init_serv_addr(&serv_addr);
int n;
pid_t pid = getpid();
// 建立 tcp 连接
int res = connect(fd, (struct sockaddr *)(&serv_addr), sizeof(serv_addr));
if(res < 0){
printf("[client ] connect failed, res: %d, errno: %d\n", res, errno);
}else printf("[client] %d connect successfully !\n", pid);
// 读取从服务器传回的数据
// 阻塞
n = read(fd,buf, sizeof(buf));
if(n > 0) printf("[client] %d, Message received from server: %s\n",pid, buf);
// 关闭套接字
close(fd);
printf("[client] client close: %d\n", getpid());
return 0;
}

server

/*
 * @Author: sjhuang
 * @Date: 2022-03-05 16:35:28
 * @LastEditTime: 2022-03-11 12:44:02
 * @FilePath: /computer_network/src/socket_c/single_socket_c/server.c
 */
#include "single_socket.h"
int main(int argc, char **argv){

    // listenfd 监听 fd
    // connfd 连接 fd
    int listenfd, connfd;
    char buff[30];
    // 创建套接字，获取 listenfd
    listenfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    // 常见 sockaddr 结构
    struct sockaddr_in serv_addr;
    // 填充 0
    memset(&serv_addr, 0, sizeof(serv_addr));
    init_serv_addr(&serv_addr);
    // 监听， 将服务器协议地址赋予给一个套接字
    bind(listenfd, (struct sockaddr*)&serv_addr,sizeof(serv_addr));
    // 监听 listenfd, 将获取的 SYN 的连接放入 SYN_RCVD 队列中
    listen(listenfd, BACK_LOG);
    // char buf[1024];
     // 客户端地址
    // int client_num = 0;
    struct sockaddr_in cli_addr;
    socklen_t addrlen = sizeof(cli_addr);
    for(; ;){
        errno = 0;
        // 从 established 队列中获取连接，
        // 如果队列为空，则阻塞此处
        connfd = accept(listenfd,(struct sockaddr*)&cli_addr, &addrlen);
        if(connfd <= 0){
            printf("[Server] connection error : %d",errno);
            break;
        }
        printf("[Server] connection from %s port: %d\n", inet_ntop(AF_INET, &cli_addr.sin_addr,buff, sizeof(buff)),ntohs(cli_addr.sin_port));
        char str[] = "hello world!\n";
        // 向客户端发送数据
        write(connfd,str, sizeof(str));
        if(errno != 0){
           printf("[Server]  connect error: %d\n", errno);
        }
        // 关闭连接
        close(connfd);
    }
    close(listenfd);
    printf("[Server]  connect close: %d\n", getpid());
    return 0;
}