msg1.c

来自「国嵌所有的实验代码」· C语言 代码 · 共 59 行

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>

struct my_msg_st
{
    long int my_msg_type;
	char some_text[BUFSIZ];
};

int main(void)
{
    int running=1;
	int msgid;
	struct my_msg_st some_data;
	long int msg_to_receive=0;

	/*创建消息队列*/
	msgid=msgget((key_t)1234,0666 | IPC_CREAT);
	if(msgid==-1)
	{
	    fprintf(stderr,"msgget failed with error: %d\n",errno);
		exit(EXIT_FAILURE);
	}
	
	/*循环从消息队列中接收消息*/
	while(running)
	{
		/*读取消息*/
	    if(msgrcv(msgid,(void *)&some_data,BUFSIZ,msg_to_receive,0)==-1)
		{
		    fprintf(stderr,"msgrcv failed with error: %d\n",errno);
			exit(EXIT_FAILURE);
		}

		printf("You wrote: %s",some_data.some_text);

		/*接收到的消息为“end”时结束循环*/
		if(strncmp(some_data.some_text,"end",3)==0)
		{
		    running=0;
		}
	}

	/*从系统内核中移走消息队列*/
	if(msgctl(msgid,IPC_RMID,0)==-1)
	{
	    fprintf(stderr,"msgctl(IPC_RMID) failed\n");
		exit(EXIT_FAILURE);
	}
	exit(EXIT_SUCCESS);
}