#include <stdio.h>

#include <sys/types.h>          /* See NOTES */

#include <sys/socket.h>

#include <unistd.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <string.h>

#include <stdlib.h>

void do_service(int conn)

{

        char recvbuf[];

        while()

        {

                memset(recvbuf,,sizeof(recvbuf));

                int ret = read(conn,recvbuf,sizeof(recvbuf));

                if(ret == )

                {

                        printf("client close\n");

                        break;

                }

                else if (ret == -)

                {

                        printf("read failed \n");

                        exit();

                }

                fputs(recvbuf,stdout);

                write(conn,recvbuf,ret);

        }

}

int main(void)

{

        int listenfd;

        listenfd = socket(PF_INET,SOCK_STREAM,);

        if(listenfd < )

        {

                printf("creat socket failed\n");

                exit();

        }

        struct sockaddr_in servaddr;

        memset(&servaddr,,sizeof(servaddr));

        servaddr.sin_family = AF_INET;

        servaddr.sin_port = htons();

        servaddr.sin_addr.s_addr = htonl(INADDR_ANY);//host any address

        int n=;

        if(setsockopt(listenfd,SOL_SOCKET,SO_REUSEADDR,&n,sizeof(n))<)

        {

                printf("set resueaddr failed\n");

                exit();

        }

        if(bind(listenfd,(struct sockaddr*)&servaddr,sizeof(servaddr))<)

        {

                printf("bind fialed\n");

                exit();

        }

        if(listen(listenfd,SOMAXCONN)<)

        {

                printf("listen failed\n");

                exit();

        }

        struct sockaddr_in peeraddr;

        socklen_t peerlen = sizeof(peeraddr);

        int conn;

        pid_t pid;

        while()

        {

                if((conn=accept(listenfd,(struct sockaddr*)&peeraddr,&peerlen))<)

                {

                        printf("accept failed\n");

                        exit();

                }

                printf("ip=%s, port=%d\n",inet_ntoa(peeraddr.sin_addr),ntohs(peeraddr.

sin_port));

                pid = fork();

                if(pid == -)

                {

                        printf("fork failed\n");

                        exit();

                }

                if (pid == )

                {

                        close(listenfd);

                        do_service(conn);

                        exit();

                }

                else

                {

                        close(conn);

                }

        }

        return ;

}