TCP/IP编程之connect函数与accept函数的关系

谁借莪１个温暖的怀抱￠ 2022-06-06 03:18 287阅读 0赞

**一、原理**

connect函数成功，并不代表服务器应用程序已经调用accept函数

我是图：

![20171028163358080][]

**二、测试**

客户端代码：

#include <stdio.h>
    #include <sys/types.h>
    #include <sys/socket.h>
    #include <netinet/in.h>
    #include <arpa/inet.h>
    #include <stdlib.h>
    #include <unistd.h>
    #include <sys/epoll.h>
    #include <fcntl.h>
    #include <errno.h>
    #include <string.h>
    
    int main()
    {
        struct sockaddr_in servaddr;
        short port = 80;
        int sockfd = socket(AF_INET, SOCK_STREAM, 0);
        servaddr.sin_family = AF_INET;
        servaddr.sin_addr.s_addr = inet_addr("192.168.1.107");
        servaddr.sin_port = htons(port);
        if (connect(sockfd, (sockaddr *) &servaddr, sizeof(sockaddr_in)) < 0) {
            if (errno != EINPROGRESS) {
                perror("connect fail");
                close(sockfd);
                return -1;
            }
        }
        printf("connect success\n");
        sleep(600);
    }

服务器代码：

#include <stdio.h>
    #include <stdlib.h>
    #include <sys/types.h>
    #include <sys/socket.h>
    #include <netinet/in.h>
    #include <arpa/inet.h>
    #include <unistd.h>
    #include <fcntl.h>
    #include <errno.h>
    #include <string.h>
    
    int main()
    {
        // socket
        int listenfd;
        struct sockaddr_in servaddr;
        short port = 80;
    
        servaddr.sin_family = AF_INET;
        servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
        servaddr.sin_port = htons(port);
    
        listenfd = socket(AF_INET, SOCK_STREAM, 0);
        int res = bind(listenfd, (sockaddr *)&servaddr, sizeof(servaddr));
        if (0 == res)
            printf("server bind success, 0.0.0.0:%d\n", port);
        else {
            perror("bind fail");
            exit(EXIT_FAILURE);
        }
        res = listen(listenfd, 100);
        if (0 == res)
            printf("server listen success\n");
        else {
            perror("listen fail");
            exit(EXIT_FAILURE);
        }
    
        // 不调用accept
        sleep(600);
    
    }

测试结果：

![20171028164438188][]

原文出自：[http://blog.csdn.net/daiyudong2020/article/details/78376995][http_blog.csdn.net_daiyudong2020_article_details_78376995]

End；

[20171028163358080]: /images/20220606/a4f9534d4409402aae599e89cf3766b0.png
[20171028164438188]: /images/20220606/a5a6c79e22e74acb8c9f11b0c04f6171.png
[http_blog.csdn.net_daiyudong2020_article_details_78376995]: http://blog.csdn.net/daiyudong2020/article/details/78376995