Operating System- CS604 Assignment 1Spring 2011 idea solution

[Vuhelper]

Operating System- CS604
Assignment # 1
Spring 2011
Marks: 20
Due Date
Your assignment must be uploaded before or on April 18, 2011
Objective
The objective of this assignment is to familiarize with the system calls.
Instructions
 Avoid Plagiarism. No marks will be given in case of cheating or copying from the
internet or from other students.
 Submit the assignment through your account on VULMS. No assignment will be
accepted through email after the due date.
 If you have any problem related to assignment, feel free to discuss it by email at
cs604@vu.edu.pk
Question # 1:
Read the following program carefully and write the output of the program. Explain each
line of code according to given numbering.
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
1……………… int main (void)
{
pid_t pid;
2………………………… pid = fork();
3…………………………. if (pid > 0)
{
int i;
4………………………… for (i = 0; i < 5; i++)
{
5………………… …………… printf(" I AM VU : %d\n", i);
6………………… …………… sleep(1);
}
exit(0);
}
7………………… ……… else if (pid == 0)
{
int j;
for (j = 0; j < 5; j++)
{
8……………………………… printf(" I have no child: %d\n", j);
sleep(1);
}
_exit(0);
}
else
{
9………………………………fprintf(stderr, "can't fork, error %d\n", errno);
10……………… … ………… exit (EXIT_FAILURE);
}
}