sharememory.c

//进程通信，共享存储区

#include <unistd.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <netdb.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <ctype.h>

#include <errno.h>

#include <malloc.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <sys/ioctl.h>

#include <stdarg.h>

#include <fcntl.h>

#include <fcntl.h>







#include<sys/types.h>

#include<sys/shm.h>

#include<sys/ipc.h>



#define SHMKEY 75

int shmid,i;

int *addr;



void client()

{

    int i;

    shmid=shmget(SHMKEY,1024,0777);

    addr=shmat(shmid,0,0);

    for(i=9;i>=0;i--)

    {

        while(*addr!=-1);

        printf("(client)sent\n");

        *addr=i;

    }

    exit(0);

}



void server()

{

    shmid=shmget(SHMKEY,1024,0777|IPC_CREAT);

    addr=shmat(shmid,0,0);

    do

    {

        *addr=-1;

        while(*addr==-1);

        printf("(server)received\n");

    }while(*addr);

    shmctl(shmid,IPC_RMID,0);

    exit(0);

}



main()

{

    while((i=fork())==-1);

    if(!i)server();

    system("ipcs -m");

    while((i=fork())==-1);

    if(!i)client();

    wait(0);

    wait(0);

}