linux 訊息佇列簡單常式

1.首先介紹下BUFSIZ這個關鍵字什麼意思：

BUFSIZ[=8192],這個值在你的stdio.h的182行有申明

2.發送端程式

 

snd.c#include<stdlib.h>#include<stdio.h>#include<unistd.h>#include<string.h>#include<sys/types.h>#include<sys/ipc.h>#include<sys/msg.h>#define MAX_TEXT 512struct my_msg_st{    int my_msg_type;    char msg_text[MAX_TEXT];};int main(int argc,char *argv[]){    int running=1;    struct my_msg_st some_data;    int msgid;    char buffer[BUFSIZ];        if((msgid=msgget((key_t)12345,0666|IPC_CREAT))==-1)    {        perror("msgget");        exit(EXIT_FAILURE);    }    while(running)    {        printf("Enter the mssage to send:");        fgets(buffer,BUFSIZ,stdin);        some_data.my_msg_type=1;        strcpy(some_data.msg_text,buffer);        if((msgsnd(msgid,(void *)&some_data,MAX_TEXT,0))==-1)        {            perror("msgsnd");            exit(EXIT_FAILURE);        }        if(strncmp(buffer,"end",3)==0)        {            running=0;        }    }    return 0;}

3.接收端

rec.c//this is the receiver program#include<stdlib.h>#include<stdio.h>#include<string.h>#include<unistd.h>#include<sys/types.h>#include<sys/ipc.h>#include<sys/msg.h>struct my_msg_st{int my_msg_type;char msg_text[BUFSIZ];};int main(int argc,char *argv[]){int running=1;int msgid;struct my_msg_st some_data;int msg_to_receive=0;if((msgid=msgget((key_t)12345,0666 | IPC_CREAT))==-1){perror("msgget");exit(EXIT_FAILURE);}while(running){if(msgrcv(msgid,(void *)&some_data,BUFSIZ,msg_to_receive,0)==-1){perror("msgrcv");exit(EXIT_FAILURE);}printf("receiver mssage:%s",some_data.msg_text);if(strncmp(some_data.msg_text,"end",3)==0)running=0;}if(msgctl(msgid,IPC_RMID,0)==-1){fprintf(stderr,"msgctl(IPC_RMID) failed\n");exit(EXIT_FAILURE);}return 0;}