进程间共享存储区通信机制的使用

进程间共享存储区通信机制的使用 
使用共享内存机制实现一定长度的消息的发送和接收。 

#include<stdio.h>
#include<sys/types.h>
#include<sys/ipc.h>
#include<sys/msg.h>
#define buffersize 1024
#define Key 1
int main()
{
      int p;
      while((p=fork())==-1);
      if(p==0)
     {
       int pid;
       sleep(5);
       pid=shmget(Key,buffersize,IPC_CREAT|0600);
       char *addr;
       addr=(char *)shmat(pid,NULL,0);
       printf("receive msg is:%s\n",addr);
       shmdt(addr);
      }
     else
    {
  int pid;
  pid=shmget(Key,buffersize,IPC_CREAT|0600);
  char *addr;
  addr=(char *)shmat(pid,NULL,0);
  strcpy(addr," This is the message which the parent have sent!");