AcceptErrorConnect.cpp

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>

int main(int argc,char* argv[])
{
    if (argc <= 2)
    {
        printf("usage: %s ip_address port_number\n",basename(argv[0]));
        return 1;
    }

    const char* ip =  argv[1];
    int port = atoi(argv[2]);
    struct sockaddr_in address;
    // 初始化端口地址
    bzero(&address,sizeof(address));
    
    address.sin_family = AF_INET;
    inet_pton(AF_INET,ip,&address.sin_addr);
    address.sin_port = htons(port);
    int sock = socket(PF_INET,SOCK_STREAM,0);
    assert(sock >= 0);

    int ret = bind(sock,(struct sockaddr* )&address,sizeof(address) );
    assert(ret != -1);
    ret = listen(sock,5);
    assert(ret != -1);
    // 暂停20秒以等待客户端连接和相关操作（掉线或者退出）完成
    sleep(20);

    struct sockaddr_in client;
    socklen_t client_addrlength = sizeof(client);
    int connfd = accept(sock,(struct sockaddr*)&client,&client_addrlength);
    if (connfd < 0)
    {
        /* code */
        printf("errno is: %d\n",errno);
    }
    else
    {
        // 接受连接成功则打印出客户端的IP地址和端口号
        char remote[INET_ADDRSTRLEN];
        printf("conneccted with ip: %s and port:%d\n",inet_ntop(AF_INET,&client.sin_addr,
        remote,INET_ADDRSTRLEN),ntohs(client.sin_port));

        close(connfd);
    }

    close(sock);
    return 0;
}