Java Semester Java 2010

java semester 2010 Question Paper

Message Queues

#include <stdio.h>

#include <stdlib.h>

#include <errno.h>

#include <string.h>

#include <sys/types.h>

#include <sys/ipc.h>

#include <sys/msg.h>

struct my_msgbuf {

long mtype;

char mtext[200];

};

int main(void)

{

struct my_msgbuf buf;

int msqid;

key_t key;

if ((key = ftok("unix3.c", 'B')) == -1) {

perror("ftok");

exit(1);

}

if ((msqid = msgget(key, 0644 | IPC_CREAT)) == -1) {

perror("msgget");

exit(1);

}

printf("Enter lines of text, ^D to quit:\n");

buf.mtype = 1;

while(fgets(buf.mtext, sizeof buf.mtext, stdin) != NULL) {

int len = strlen(buf.mtext);

if (buf.mtext[len-1] == '\n') buf.mtext[len-1] = '\0';

if (msgsnd(msqid, &buf, len+1, 0) == -1)

perror("msgsnd");

}

if (msgctl(msqid, IPC_RMID, NULL) == -1) {

perror("msgctl");

exit(1);

}

return 0;

}