linux-ipc-message-queues's Introduction

Linux-IPC-Message-Queues

Linux IPC-Message Queues

AIM:

To write a C program that receives a message from message queue and display them

DESIGN STEPS:

Step 1:

Navigate to any Linux environment installed on the system or installed inside a virtual environment like virtual box/vmware or online linux JSLinux (https://bellard.org/jslinux/vm.html?url=alpine-x86.cfg&mem=192) or docker.

Step 2:

Write the C Program using Linux message queues API

Step 3:

Execute the C Program for the desired output.

PROGRAM:

C program that receives a message from message queue and display them

writer .c

// C Program for Message Queue (Writer Process) 
#include <stdio.h>
#include <unistd.h>
#include <sys/ipc.h>
#include <sys/msg.h>
// structure for message queue
struct mesg_buffer {
long mesg_type;
char mesg_text[100];
} message;
int main()
{ key_t key;
int msgid;
// ftok to generate unique key
key = ftok("progfile", 65);
// msgget creates a message queue
// and returns identifier
msgid = msgget(key, 0666 | IPC_CREAT);
message.mesg_type = 1;
printf("Write Data : ");
gets(message.mesg_text);
// msgsnd to send message
msgsnd(msgid, &message, sizeof(message), 0);
// display the message
printf("Data send is : %s \n", message.mesg_text);
return 0;
}

reader.c

// C Program for Message Queue (Reader Process)
#include <stdio.h>
#include <sys/ipc.h>
#include <sys/msg.h>
// structure for message queue
struct mesg_buffer {
long mesg_type;
char mesg_text[100];
} message;
int main()
{
key_t key;
int msgid;
// ftok to generate unique key
key = ftok("progfile", 65);
// msgget creates a message queue
// and returns identifier
msgid = msgget(key, 0666 | IPC_CREAT);
// msgrcv to receive message
msgrcv(msgid, &message, sizeof(message), 1, 0);
// display the message
printf("Data Received is : %s \n",message.mesg_text);
// to destroy the message queue
msgctl(msgid, IPC_RMID, NULL);
return 0;
}