c - 编程 C : getting error when binding address and port to socket

Question

我真的不知道我做错了什么。我包括了所有好的图书馆。并在我的 VPS 和本地 Ubuntu 安装上对其进行了测试。我还查找了可以正常工作的同一程序的其他代码。但我不断收到“错误:无法将 Internet 地址绑定(bind)到套接字方法”消息。 这是我用 C 代码编写的 TCP 服务器:

#include <stdio.h>
#include <strings.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <netinet/in.h>
#include <stdlib.h>

//Enter The Port and the Ip Address here.

#define PORT 666
#define ADRESS 0

//Enter the amount of Maximum Poeple entering the server.
#define NUMBER_OF_CONNECTIONS 8

int main(){
    int sockfd, newsockfd, portno = 666, clilen;
    char message[1024];
    struct sockaddr_in serv_addr, cli_addr;
    int n;

    sockfd = (AF_INET, SOCK_STREAM, 0);

    if (sockfd < 0){
        printf("ERROR: could not create server-socket.\n");
        exit(1);
    }

    bzero((char *) &serv_addr, sizeof(serv_addr));

    // Declaring the port.
    //portno = 666;
    // Declaring the type of connection. (internet connection)
    serv_addr.sin_family =  AF_INET;
    // Declaring the IP.
    serv_addr.sin_addr.s_addr = INADDR_ANY;
    // Declaring the Port.
    serv_addr.sin_port = htons(portno);

    // Binding the Socket?
    if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0){
        printf("ERROR: could not bind internet address to the socket method.\n");
        exit(1);
    }

    // Entering "Listen Mode".
    listen(sockfd, NUMBER_OF_CONNECTIONS);
    clilen = sizeof(cli_addr);

    // Creating a New Socket for the client.
    newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);

    if (newsockfd < 0){
        printf("ERROR: could not accept connection.\n");
        exit(1);
    }

    //Clearing the message-buffer.
    bzero(message,1024);

    // Reading the message.
    n = read(newsockfd,message,1023);

    if (n < 0){
        printf("ERROR: could not read message.\n");
    }

    printf("Message: %s\n",message);

    n = write(newsockfd, "I got your message.", 18);

    if (n < 0)
    {
        printf("ERROR: sending to client.\n");
    }
    return 0;
}

Answer 1

问题是这一行:

 sockfd = (AF_INET, SOCK_STREAM, 0);

它是有效的，右侧的表达式计算为 0(请参阅 C 中的逗号运算符)。

现在对 bind() 的调用被放置在 fd 0 上，它通常是一个(伪)终端。这不可能成功。

解决方法是:

 sockfd = socket(AF_INET, SOCK_STREAM, 0);