linux 下消息队列编程

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最新推荐文章于 2025-09-05 23:07:29 发布

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本文提供了一个使用消息队列进行进程间通信的C语言示例程序，包括发送端和接收端的实现代码。该程序演示了如何创建消息队列、发送消息以及接收并处理这些消息。

写消息：

#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>

#define MAX_TEXT 512

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

int main(void)
{
int running=1;
int msgid;
struct my_msg_st some_data;
char buffer[BUFSIZ];
/*创建消息队列*/
msgid=msgget((key_t)1234,0666|IPC_CREAT);
if(msgid==-1)
{
    fprintf(stderr,"msgget failed with error: %d",errno);
    exit(EXIT_FAILURE);
}
/*循环从消息队列中添加消息*/
while(running)
{
      printf("Enter some text:");
      fgets(buffer,BUFSIZ,stdin);
      some_data.my_msg_type=1;//？why
      strcpy(some_data.some_text,buffer);
      printf("you wrote :%s \n",some_data.some_text);
      /*添加消息*/
      if(msgsnd(msgid,(void *)&some_data,MAX_TEXT,0)==-1)
      {
         fprintf(stderr,"msgsnd failed \n");
         exit(EXIT_FAILURE);
       }

   /*用户输入的为“end”是结束循环*/
   if(strncmp(buffer,"end",3)==0)
    {
       running=0;
     }

}
   exit(EXIT_SUCCESS);
}

读消息：

#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;//??为什么非的定义个？
/*创建消息队列*/
msgid=msgget((key_t)1234,0666|IPC_CREAT);
if(msgid==-1)
{
    fprintf(stderr,"msgget failed with error: %d",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 \n",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);
}
/*
# define BUFSIZ _IO_BUFSIZ stdlib.h 中定义的BUFSIZ 但不知是什么？
*/