进程间通信之消息队列

消息队列是什么？

消息队列提供了一种从一个进程向另一个进程发送一个数据块的方法。

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/msg.h>
#include <errno.h>

#define MAX_TEXT 512
struct msg_st
{
	long int msg_type;
	char text[MAX_TEXT];
};

int main()
{
	int running = 1;
	struct msg_st data;
	char buffer[BUFSIZ];
	int msgid = -1;

	//建立消息队列
	msgid = msgget((key_t)1234, 0666 | IPC_CREAT);
	if(msgid == -1)
	{
		fprintf(stderr, "msgget failed with error: %d\n", errno);
		exit(EXIT_FAILURE);
	}

	//向消息队列中写消息，直到写入end
	while(running)
	{
		//输入数据
		printf("Enter some text: ");
		fgets(buffer, BUFSIZ, stdin);
		data.msg_type = 1;    //注意2
		strcpy(data.text, buffer);
		//向队列发送数据
		if(msgsnd(msgid, (void*)&data, MAX_TEXT, 0) == -1)
		{
			fprintf(stderr, "msgsnd failed\n");
			exit(EXIT_FAILURE);
		}
		//输入end结束输入
		if(strncmp(buffer, "end", 3) == 0)
			running = 0;
		sleep(1);
	}
	exit(EXIT_SUCCESS);
}

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/msg.h>
#include <errno.h>

#define MAX_TEXT 512
struct msg_st
{
	long int msg_type;
	char text[MAX_TEXT];
};

int main()
{
	int running = 1;
	struct msg_st data;
	char buffer[BUFSIZ];
	int msgid = -1;

	//建立消息队列
	msgid = msgget((key_t)1234, 0666 | IPC_CREAT);
	if(msgid == -1)
	{
		fprintf(stderr, "msgget failed with error: %d\n", errno);
		exit(EXIT_FAILURE);
	}

	//向消息队列中写消息，直到写入end
	while(running)
	{
		//输入数据
		printf("Enter some text: ");
		fgets(buffer, BUFSIZ, stdin);
		data.msg_type = 1;    //注意2
		strcpy(data.text, buffer);
		//向队列发送数据
		if(msgsnd(msgid, (void*)&data, MAX_TEXT, 0) == -1)
		{
			fprintf(stderr, "msgsnd failed\n");
			exit(EXIT_FAILURE);
		}
		//输入end结束输入
		if(strncmp(buffer, "end", 3) == 0)
			running = 0;
		sleep(1);
	}
	exit(EXIT_SUCCESS);
}

原文：http://blog.csdn.net/u014338577/article/details/47704039