Linux MCQ Questions & Answers | Computer Science

#include<stdio.h>
#include<stdlib.h>
 
int main()
{
    int ret;
    int *ptr;
    ptr = (int *)malloc(sizeof(int)*10);
    free(ptr);
    free(ptr);
    return 0;
}

#!/bin/bash
a=1; b=2; c=3
d=$(( ++a**b*c++ + a ))
echo $d
exit 0

#! /usr/bin/awk -f
BEGIN {
    a=6
    do {
        print "example"
        a++
    } while (a<5)
}

#include<stdio.h>
#include<fcntl.h>
 
int main()
{
    int fd, count;
    char buff[10];
    if (mkfifo("/tmp/test_fifo",0666) != 0)
        perror("mkfifo");
    fd = open("/tmp/test_fifo",O_RDONLY|O_NONBLOCK);
    count = read(fd,buff,10);
    printf("%d\n",count);
    return 0;
}

#include<stdio.h>
#include<stdlib.h>
#include<sys/types.h>
#include<sys/ipc.h>
#include<sys/sem.h>
 
static int sem_p(void);
static int sem_v(void);
union semun{
    int val;
    struct semid_ds *buf;
    unsigned short array;
};
int sem_id;
struct semid_ds myds;
struct sembuf mybuf;
union semun myun;
static int sem_p(void)
{
    mybuf.sem_num = 0;
    mybuf.sem_op = -1;
    mybuf.sem_flg = SEM_UNDO;
    semop(sem_id,&mybuf,1);
}
static int sem_v(void)
{
    mybuf.sem_num = 0;
    mybuf.sem_op = 1;
    mybuf.sem_flg = SEM_UNDO;
    semop(sem_id,&mybuf,1);
}
int main()
{
    int wfd, rfd;
    sem_id = semget((key_t)911,1,0666 | IPC_CREAT);
    myun.val = 1;
    semctl(sem_id,0,SETVAL,myun);
    sem_p();
    printf("Example\n");
    sem_v();
    semctl(sem_id,0,IPC_RMID,myun);
    return 0;
}