//p2p点对点聊天多进程版--服务器(信号的使用)

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <errno.h>

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

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <signal.h>

#include <sys/wait.h>

void handler(int sign)

{

    if(sign==SIGUSR1)

        printf("recv signal!\n");

    exit();

}

int main(int arg, char *args[])

{

    //create socket

    int sockfd = socket(AF_INET, SOCK_STREAM, );

    if (sockfd == -)

    {

        perror("socket() err");

        return -;

    }

    //reuse server socket

    int optval = ;

    if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval))

            == -)

    {

        perror("setsockopt() err");

        return -;

    }

    //bind port and ip

    struct sockaddr_in addr;

    addr.sin_family = AF_INET;

    addr.sin_port = htons();

    addr.sin_addr.s_addr = inet_addr("127.0.0.1");

    if (bind(sockfd, (struct sockaddr *) &addr, sizeof(addr)) == -)

    {

        perror("bind() err");

        return -;

    }

    //listen 维护两个队列

    if (listen(sockfd, SOMAXCONN) == -)

    {

        perror("listen() err");

        return -;

    }

    //accept

    struct sockaddr_in peeraddr;

    socklen_t peerlen = sizeof(peeraddr);

    int conn = accept(sockfd, (struct sockaddr *) &peeraddr, &peerlen);

    if (conn == -)

    {

        perror("accept() err");

        return -;

    }

    printf("accept by %s\n", inet_ntoa(peeraddr.sin_addr));

    pid_t pid = ;

    pid = fork();

    if (pid == -)

    {

        perror("fork() err");

        return -;

    }

    //父进程接收客户端信息，打屏

    if (pid > )

    {

        char recvbuf[] = {  };

        int rc = ;

        while ()

        {

            rc = read(conn, recvbuf, );

            if (rc < )

            {

                perror("read() err");

                break;

            } else if (rc == )

            {

                printf("client is closed !\n");

                break;

            }

            //printf("%s\n");

            write(STDOUT_FILENO, recvbuf, rc);

            memset(recvbuf, , );

        }

        //发送信号，关闭子进程

        kill(pid,SIGUSR1);

        //关闭客户端连接套接字

        close(conn);

        close(sockfd);

        //等待子进程

        int ret=;

        while()

        {

            ret=wait(NULL);

            printf("子进程pid=%d\n",ret);

            if(ret==-)

            {

                if(errno==EINTR)

                    continue;

                break;

            }

        }

    }

    //子进程读取用户输入，发送给客户端

    if (pid == )

    {

        //安装信号

        struct sigaction act;

        act.sa_handler=handler;

        sigemptyset(&act.sa_mask);

        act.sa_flags=;

        if(sigaction(SIGUSR1,&act,NULL)==-)

        {

            printf("sigaction() failed! \n");

            exit();

        }

        //关闭服务器监听套接字

        close(sockfd);

        char sendbuf[] = {  };

        while ()

        {

            if (read(STDIN_FILENO, sendbuf, ) == -)

            {

                perror("read() err");

                //关闭客户端连接套接字

                close(conn);

                exit();

            }

            write(conn, sendbuf, strlen(sendbuf));

            memset(sendbuf, , );

        }

    }

    return ;

}

//p2p点对点聊天多进程版--客户端

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <errno.h>

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

#include <sys/socket.h>

#include <netinet/in.h>

#include <arpa/inet.h>

int main(int arg, char *args[])

{

    int sockfd = socket(AF_INET, SOCK_STREAM, );

    if (sockfd == -)

    {

        perror("socket() err");

        return -;

    }

    //connect

    struct sockaddr_in addr;

    addr.sin_family = AF_INET;

    addr.sin_port = htons();

    addr.sin_addr.s_addr = inet_addr("127.0.0.1");

    if (connect(sockfd, (struct sockaddr *) &addr, sizeof(addr)) == -)

    {

        perror("connect() err");

        return -;

    }

    pid_t pid = ;

    pid = fork();

    if (pid == -)

    {

        perror("fork() err");

        return -;

    }

    int rc = ;

    char buf[] = {  };

    //子进程接收信息

    if (pid == )

    {

        while ()

        {

            rc = read(sockfd, buf, );

            if (rc < )

            {

                perror("read err");

                close(sockfd);

                exit();

            } else if (rc == )

            {

                printf("server closed!\n");

                close(sockfd);

                exit();

            }

            write(STDOUT_FILENO, buf, rc);

            memset(buf, , );

        }

    }

    //父进程发送数据

    if (pid > )

    {

        while ()

        {

            if (read(STDIN_FILENO, buf, ) == -)

            {

                perror("read() err");

                close(sockfd);

                exit();

            }

            write(sockfd, buf, strlen(buf));

            memset(buf, , );

        }

    }

    return ;

}

.SUFFIXES:.c .o

CC=gcc

SRCS1=tec01.c

SRCS2=hello.c

OBJS1=$(SRCS1:.c=.o)

OBJS2=$(SRCS2:.c=.o)

EXEC1=runc

EXEC2=hello

start:$(OBJS1) $(OBJS2)

    $(CC) -o $(EXEC1) $(OBJS1)

    $(CC) -o $(EXEC2) $(OBJS2)

    @echo "--------OK--------"

.c.o:

    $(CC) -Wall -g -o $@ -c $<

clean:

    rm -f $(OBJS1)

    rm -f $(EXEC1)

    rm -f $(OBJS2)

    rm -f $(EXEC2)