sy1.c

linux中接受和发送信息,分同步和异步,是操作系统的上机题

#include <stdio.h> 
#include <sys/types.h>
#include <sys/msg.h>
#include <sys/ipc.h>
#define MSGKEY 75
struct msgbuf {
                 long mtype;     /* message type, must be > 0 */
                 char mtext[100];  /* message data */
            }msg;
int qid;
void server()
{
	qid=msgget(MSGKEY,0777|IPC_CREAT);
	do{
	msgrcv(qid,&msg,100,0,0);
	printf("server receive\n");
	}while(msg.mtype!=1);
	 msgctl(qid, IPC_RMID,0);
   	exit(0);


} 
void client( )
{
	int i;
	do{
	qid=msgget(MSGKEY,0777);
	}while(qid==-1);	
	for(i=10;i>=1;i--)
	{
		 msg.mtype=i;
		 printf("client sent\n");
 		 msgsnd(qid,&msg,99,0);       /*发送消息msg入msgid消息队列*/
	}
	exit(0);
}

int main()
{
	//printf("%d  %d",IPC_NOWAIT, MSG_NOERROR);
	if(fork()) server();
	else client( );
 	wait(0);
	wait(0);
	exit(0);
	return 1;
}