server.c

/*
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 */

/* 
 * File:   main.c
 * Author: Mr Mahaitao
 *
 * Created on March 6, 2018, 3:44 AM
 */

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <arpa/inet.h>
#define SERVPORT 3333 /*服务器监听端口号*/
#define BACKLOG 10 /*最大同时连接请求数*/

/*
 * 
 */
int main(int argc, char** argv) {

    int sockfd, client_fd; /*sock_fd:监听socket; client_fd:数据传输socket*/
    struct sockaddr_in my_addr; /*本机地址信息*/
    struct sockaddr_in remote_addr; /*客户端信息*/
    int sin_size;

    if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
        perror("socket 创建失败！");
        exit(1);
    }

    my_addr.sin_family = AF_INET;
    my_addr.sin_port = htons(SERVPORT); /*htons()把16位值从主机字节序转换成网络字节序*/
    my_addr.sin_addr.s_addr = htonl(INADDR_ANY); /*IP地址设置成INADDR_ANY,让系统自动获取本机的IP地址*/
    bzero(&(my_addr.sin_zero), 8); /*保持与struct sockaddr同样大小*/

    if (bind(sockfd, (struct sockaddr *) &my_addr, sizeof (struct sockaddr)) == -1) {
        perror("bind 失败！");
        exit(1);
    }

    if (listen(sockfd, BACKLOG) == -1) {
        perror("lisnten 失败！");
        exit(1);
    }

    while (1) {
        sin_size = sizeof (struct sockaddr_in);
        if ((client_fd = accept(sockfd, (struct sockaddr *) &remote_addr, &sin_size)) == -1) {
            perror("accept 失败!");
            continue;
        }
        printf("收到一个来自：%s\n", inet_ntoa(remote_addr.sin_addr));
        if (!fork()) { /*子进程代码段*/
            if (send(client_fd, "连接上了 \n", 26, 0) == -1)
                perror("send 失败！");
            close(client_fd);
            exit(0);
        }
        close(client_fd);
    }

    return (EXIT_SUCCESS);
}