int sock_fd = socket(AF_INET, SOCK_STREAM, 0);中文解释一下这段代码

这段代码创建了一个套接字(socket)并返回套接字的文件描述符(sock_fd)。

其中，AF_INET是套接字的地址族，表示IPv4；SOCK_STREAM是套接字的类型，表示基于TCP协议的可靠连接；0代表选择默认的协议，通常为TCP协议。

该函数返回一个非负整数文件描述符，表示套接字文件，可以在后续的数据传输操作中使用该文件描述符进行读写操作。

相关问题

修改client.c： #include<stdio.h> #include<stdlib.h> #include<string.h> #include<errno.h> #include<sys/types.h> #include<sys/socket.h> #include<netinet/in.h> int main() { int ret = 0; int socket_fd; char buffer[100]="你好，我是xxx!"; struct sockaddr_in server_add; socket_fd = socket(AF_INET, SOCK_STREAM, 0); if(-1 == socket_fd) { printf("socket fail ! \r\n"); return -1; } bzero(&server_add,sizeof(struct sockaddr_in)); server_add.sin_family=AF_INET; server_add.sin_addr.s_addr= inet_addr("192.168.1.2"); server_add.sin_port=htons(8888); if(-1 == connect(socket_fd,(struct sockaddr *)(&server_add), sizeof(struct sockaddr))) { printf("connect fail !\r\n"); return -1; } ret = write(socket_fd, buffer, strlen(buffer)); if(-1 == ret ) { printf("write fail!\r\n"); return -1; } close(socket_fd); return 0; }server.c： #include<stdio.h> #include<stdlib.h> #include<string.h> #include<errno.h> #include<sys/types.h> #include<sys/socket.h> #include<netinet/in.h> int main() { int ret = 0; int socket_fd, new_socket_fd; struct sockaddr_in server_add,client_add; int add_len; char recv_buff[100]={0}; char send_buff[100]="朕xxx知道了!"; socket_fd = socket(AF_INET, SOCK_STREAM, 0); if(-1 == socket_fd) { printf("socket fail ! \r\n"); return -1; } bzero(&server_add,sizeof(struct sockaddr_in)); server_add.sin_family=AF_INET; server_add.sin_addr.s_addr=htonl(INADDR_ANY); server_add.sin_port=htons(8888); if(-1 == bind(socket_fd,(struct sockaddr *)(&server_add), sizeof(struct sockaddr))) { printf("bind fail !\r\n"); return -1; } if(-1 == listen(socket_fd,5)) { printf("listen fail !\r\n"); return -1; } while(1) { new_socket_fd = accept(socket_fd, (struct sockaddr *)(&client_add), &add_len); if(-1 == new_socket_fd) { printf("accept fail !\r\n"); return -1; } ret = read(new_socket_fd, recv_buff,100); if(-1 == ret) { printf("read data fail !\r\n"); return -1; } printf("Now we get:%s from client!\n", recv_buff); ret = write(socket_fd, send_buff, strlen(send_buff)); if(-1 == ret ) { printf("write fail!\r\n"); return -1; } close(new_socket_fd); } close(socket_fd); return 0; }修改服务器和客户端，使朕知道了正常输出

修改后的client.c：

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<errno.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>

int main() {
    int ret = 0;
    int socket_fd;
    char buffer[100]="你好，我是xxx!";
    struct sockaddr_in server_add;

    socket_fd = socket(AF_INET, SOCK_STREAM, 0);
    if(-1 == socket_fd)
    {
        printf("socket fail ! \r\n");
        return -1;
    }

    bzero(&server_add,sizeof(struct sockaddr_in));
    server_add.sin_family=AF_INET;
    server_add.sin_addr.s_addr= inet_addr("192.168.1.2");
    server_add.sin_port=htons(8888);

    if(-1 == connect(socket_fd,(struct sockaddr *)(&server_add), sizeof(struct sockaddr)))
    {
        printf("connect fail !\r\n");
        return -1;
    }

    ret = write(socket_fd, buffer, strlen(buffer));
    if(-1 == ret )
    {   
        printf("write fail!\r\n");
        return -1;
    }

    ret = read(socket_fd, buffer,100);
    if(-1 == ret) {
        printf("read data fail !\r\n");
        return -1;
    }

    printf("Now we get:%s from server!\n", buffer);

    close(socket_fd);
    return 0;
}

修改后的server.c：

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<errno.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>

int main() {
    int ret = 0;
    int socket_fd, new_socket_fd;
    struct sockaddr_in server_add,client_add;
    int add_len;
    char recv_buff[100]={0};
    char send_buff[100]="朕xxx知道了!";

    socket_fd = socket(AF_INET, SOCK_STREAM, 0);
    if(-1 == socket_fd) {
        printf("socket fail ! \r\n");
        return -1;
    }

    bzero(&server_add,sizeof(struct sockaddr_in));
    server_add.sin_family=AF_INET;
    server_add.sin_addr.s_addr=htonl(INADDR_ANY);
    server_add.sin_port=htons(8888);

    if(-1 == bind(socket_fd,(struct sockaddr *)(&server_add), sizeof(struct sockaddr))) {
        printf("bind fail !\r\n");
        return -1;
    }

    if(-1 == listen(socket_fd,5)) {
        printf("listen fail !\r\n");
        return -1;
    }

    while(1) {
        new_socket_fd = accept(socket_fd, (struct sockaddr *)(&client_add), &add_len);
        if(-1 == new_socket_fd) {
            printf("accept fail !\r\n");
            return -1;
        }

        ret = read(new_socket_fd, recv_buff,100);
        if(-1 == ret) {
            printf("read data fail !\r\n");
            return -1;
        }

        printf("Now we get:%s from client!\n", recv_buff);

        ret = write(new_socket_fd, send_buff, strlen(send_buff));
        if(-1 == ret ) {
            printf("write fail!\r\n");
            return -1;
        }

        close(new_socket_fd);
    }

    close(socket_fd);
    return 0;
}

在客户端发送消息后，服务器会返回“朕xxx知道了!”，客户端会输出“Now we get:朕xxx知道了! from server!”。

翻译一下这段代码并在每一行代码后注释int ret,client_fd; char recvBuffer[128]={0}; struct sockaddr_in server_addr; socklen_t slen; client_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if(client_fd < 0) { printf("client socket failed\n"); exit(1); } server_addr.sin_family = AF_INET; server_addr.sin_port = htons(SERVERPT); server_addr.sin_addr.s_addr = inet_addr(SERVERIP); slen = sizeof(server_addr); //连接服务器 ret = connect(client_fd, (struct sockaddr *)&server_addr, slen); if(ret < 0) { printf("client connect failed\n"); exit(2); } printf("[C]client connect success.\n"); sleep(4); //给服务器发送数据 write(client_fd, "hello, server, i am client!", 128); //从服务器接收数据 read(client_fd, recvBuffer, 128); printf("server data: %s\n", recvBuffer); sleep(2); //客户端下线 printf("client quit\n"); close(client_fd);

这段代码的作用是创建一个客户端并连接到指定的服务器，发送一条消息并接收服务器返回的消息，最后关闭客户端。

int ret, client_fd;  // 定义变量ret和client_fd
char recvBuffer[128] = {0};  // 定义接收缓冲区
struct sockaddr_in server_addr;  // 定义服务器地址结构体
socklen_t slen;  // 定义地址结构体长度

client_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);  // 创建一个TCP套接字
if (client_fd < 0) {  // 如果创建失败，输出错误信息并退出程序
    printf("client socket failed\n");
    exit(1);
}

server_addr.sin_family = AF_INET;  // 指定协议族为IPv4
server_addr.sin_port = htons(SERVERPT);  // 指定服务器端口号
server_addr.sin_addr.s_addr = inet_addr(SERVERIP);  // 指定服务器IP地址
slen = sizeof(server_addr);  // 计算地址结构体长度

// 连接服务器
ret = connect(client_fd, (struct sockaddr *)&server_addr, slen);
if (ret < 0) {  // 如果连接失败，输出错误信息并退出程序
    printf("client connect failed\n");
    exit(2);
}

printf("[C]client connect success.\n");  // 连接成功，输出提示信息
sleep(4);  // 延时4秒

// 给服务器发送数据
write(client_fd, "hello, server, i am client!", 128);

// 从服务器接收数据
read(client_fd, recvBuffer, 128);
printf("server data: %s\n", recvBuffer);

sleep(2);  // 延时2秒

printf("client quit\n");  // 输出客户端下线信息
close(client_fd);  // 关闭客户端