1> 使用消息队列完成两个进程间相互

a:

#include<myhead.h>
#define MSGSIZE sizeof(struct msgbuf)-sizeof(long)
struct msgbuf
{
	long mtype;
	char mtext[1024];
 
};
int main(int argc, const char *argv[])
{
	pid_t pid=fork();
	if(pid>0)
	{
		key_t key = 0;
 
		if((key=ftok("/",'k'))==-1)
		{
			perror("ftok error");
			return -1;
		}
		printf("ftok success key = %#x\n",key);
		int msqid = -1;
		if((msqid = msgget(key,IPC_CREAT|0664))==-1)
		{
			perror("msgget error");
			return -1;
		}
		printf("msgget success msqid = %d\n",msqid);
 
		struct msgbuf sbuf;
 
		while(1)
		{
			bzero(sbuf.mtext, sizeof(sbuf.mtext));
			printf("消息类型：");
			scanf("%ld",&sbuf.mtype);
			getchar();
			printf("请输入正文：");
			fgets(sbuf.mtext,sizeof(sbuf.mtext), stdin);
			sbuf.mtext[strlen(sbuf.mtext)-1]=0;
			msgsnd(msqid,&sbuf, MSGSIZE, 0);
			printf("发送成功\n");
			if(strcmp(sbuf.mtext, "quit")==0)
			{
				break;
			}
		}
	}else if(pid==0)
	{
		key_t key1 = 0;
		if((key1=ftok("/",'k'))==-1)
		{
			perror("ftok error");
			return -1;
		}
		printf("ftok success key1 = %#x\n",key1);
		int msqid1 = -1;
		if((msqid1 = msgget(key1,IPC_CREAT|0664))==-1)
		{
			perror("msgget error");
			return -1;
		}
		printf("msgget success msqid1 = %d\n",msqid1);
 
		struct msgbuf rbuf;
 
		while(1)
		{
			bzero(rbuf.mtext, sizeof(rbuf.mtext));
			msgrcv(msqid1,&rbuf,MSGSIZE,2,0);
			printf("收到消息为：%s\n",rbuf.mtext);
			if(strcmp(rbuf.mtext, "quit")==0)
			{
				break;
			}
		}
		if(msgctl(msqid1,IPC_RMID,NULL)!=0)
		{
			perror("msgctl error");
			return -1;
		}
 
 
	}
	else
	{
		perror("fork error");
		return -1;
	}
 
	return 0;
}
 
 
 
 
 

 

b： 

#include<myhead.h>
#define MSGSIZE sizeof(struct msgbuf)-sizeof(long)
struct msgbuf
{
	long mtype;
	char mtext[1024];
 
};
int main(int argc, const char *argv[])
{
	pid_t pid=fork();
	if(pid>0)
	{
		key_t key = 0;
 
		if((key=ftok("/",'k'))==-1)
		{
			perror("ftok error");
			return -1;
		}
		printf("ftok success key = %#x\n",key);
		int msqid = -1;
		if((msqid = msgget(key,IPC_CREAT|0664))==-1)
		{
			perror("msgget error");
			return -1;
		}
		printf("msgget success msqid = %d\n",msqid);
 
		struct msgbuf sbuf;
 
		while(1)
		{
			bzero(sbuf.mtext, sizeof(sbuf.mtext));
			printf("消息类型：");
			scanf("%ld",&sbuf.mtype);
			getchar();
			printf("请输入正文：");
			fgets(sbuf.mtext,sizeof(sbuf.mtext), stdin);
			sbuf.mtext[strlen(sbuf.mtext)-1]=0;
			msgsnd(msqid,&sbuf, MSGSIZE, 0);
			printf("发送成功\n");
			if(strcmp(sbuf.mtext, "quit")==0)
			{
				break;
			}
		}
	}else if(pid==0)
	{
		key_t key1 = 0;
		if((key1=ftok("/",'k'))==-1)
		{
			perror("ftok error");
			return -1;
		}
		printf("ftok success key1 = %#x\n",key1);
		int msqid1 = -1;
		if((msqid1 = msgget(key1,IPC_CREAT|0664))==-1)
		{
			perror("msgget error");
			return -1;
		}
		printf("msgget success msqid = %d\n",msqid1);
 
		struct msgbuf rbuf;
 
		while(1)
		{
			bzero(rbuf.mtext, sizeof(rbuf.mtext));
			msgrcv(msqid1,&rbuf,MSGSIZE,1,0);
			printf("收到消息为：%s\n",rbuf.mtext);
			if(strcmp(rbuf.mtext, "quit")==0)
			{
				break;
			}
		}
		if(msgctl(msqid1,IPC_RMID,NULL)!=0)
		{
			perror("msgctl error");
			return -1;
		}
 
 
	}
	else
	{
		perror("fork error");
		return -1;
	}
 
	return 0;
}
 

 

2>思维导图