Message Queue - System Software Lab

Message Queue - MCA - System Software Lab
 
#include sys/types.h
#include sys/ipc.h
#include sys/msg.h
#include stdio.h

#define MSGSZ     128

typedef struct msgbuf {

    long    mtype;

    char    mtext[MSGSZ];

} message_buf;

main()

{

    int msqid;

    key_t key;

    message_buf  rbuf;

    printf("\n\tLab program 10 : Message Queue - Reading content from the queue\n");

    key = 10;

    if ((msqid = msgget(key, 0666)) < 0) {

        perror("msgget");

        exit(1);

    }

   

    if (msgrcv(msqid, &rbuf, MSGSZ, 1, 0) < 0) {

        perror("msgrcv");

        exit(1);

    }

    printf("\nThe Message read from the Message Queue : %s\n", rbuf.mtext);

    exit(0);

}

The above is the program to read the message from the message Queue acting as a Client program.

#include sys/types.h
#include sys/ipc.h
#include sys/msg.h
#include stdio.h
#include string.h
#include fcntl.h
#include unistd.h
#include stdlib.h

#define MSGSZ     128

typedef struct msgbuf {

         long    mtype;

         char    mtext[MSGSZ];

         } message_buf;

main()

{

    int msqid;

    int msgflg = IPC_CREAT | 0666;

    key_t key;

    message_buf sbuf;

    size_t buf_length;

    char tmsg[100];

  

    key = 10;

    printf("\n\tLab 10 : Message Queue - Sending Message to the Message Queue\n\n");

    printf("\nEnter a line to store as Message in the Queue : ");

   fgets(tmsg,100,stdin);

    printf("\nCalling msgget with key %#lx and flag %#o\n",key,msgflg);

    if ((msqid = msgget(key, msgflg )) < 0) {

        perror("msgget");

        exit(1);

    }

    else

     printf("\nmsgget: msgget succeeded: msqid = %d\n", msqid);

    sbuf.mtype = 1;

   

    printf("\nmsgget: msgget succeeded: msqid = %d\n", msqid);

   

    (void) strcpy(sbuf.mtext,tmsg);

   

    printf("\nmsgget: msgget succeeded: msqid = %d\n", msqid);

   

    buf_length = strlen(sbuf.mtext) + 1 ;

   

    if (msgsnd(msqid, &sbuf, buf_length, IPC_NOWAIT) < 0) {

       printf ("\n%d, %d, %s, %d\n", msqid, sbuf.mtype, sbuf.mtext, buf_length);

        perror("msgsnd");

        exit(1);

    }

   else

      printf("\nMessage: \"%s\" Sent\n", sbuf.mtext);

     

    exit(0);

}

The above is the program for storing content in the message Queue acting as Server program.