Linux_OS_MsgQ_Rcv.cpp

/*
 * @Author: xuezaigds@gmail.com
 * @Last Modified time: 2016-08-31 21:35:25
 */

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

struct msg_st
{
    long int msg_type;
    char text[BUFSIZ];
};

int main()
{
    int running = 1;
    int msgid = -1;
    struct msg_st data;
    long int msgtype = 2;

    //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);
    }
    //从队列中获取消息，直到遇到end消息为止
    while(running)
    {
        if(msgrcv(msgid, (void*)&data, BUFSIZ, msgtype, 0) == -1)
        {
            fprintf(stderr, "Msgrcv failed with errno: %d\n", errno);
            exit(EXIT_FAILURE);
        }
        printf("You wrote: %s\n",data.text);
        //遇到end结束
        if(strncmp(data.text, "end", 3) == 0)
            running = 0;
    }
    //删除消息队列
    if(msgctl(msgid, IPC_RMID, 0) == -1)
    {
        fprintf(stderr, "Msgctl(IPC_RMID) failed\n");
        exit(EXIT_FAILURE);
    }
    exit(EXIT_SUCCESS);
}