OPERATING SYSTEMS LAB
Subject Code: 21CSC202J
B.TECH II Year / III Semester
NAME-WAQUAS ARSHAD
REG.No.- RA2211003030319
DEPARTMENT OF COMPUTER SCIENCE ENGINEERING
SRM INSTITUTE OF SCIENCE & TECHNOLOGY,
DELHI-NCR CAMPUS, MODINAGAR SIKRI KALAN,
DELHI MEERUT ROAD, DIST. GHAZIABAD, 201204.
Odd Semester (July-Dec,2023)
SRM INSTITUTE OF SCIENCE & TECHNOLOGY, DELHI-NCR CAMPUS, MODINAGAR
BONAFIDE CERTIFICATE
Certified to be the bonafide record of work done by Waquas Arshad Reg.No.
RA2211003030319 Of IIIrd semester IInd year B.TECH degree course in SRM
INSTITUTE OFSCIENCE & TECHNOLOGY, DELHI-NCR Campus for
the Department of Computer Science & Engineering, in Operating Systems
Laboratory duringthe academic year 2023-2024.
Lab In charge
Submitted for End Semester examination held on
Head of the Department
/
/
at SRM INSTITUTE
OF SCIENCE & TECHNOLOGY, DELHI-NCR Campus.
Internal Examiner-I
Internal Examiner-II
SRM INSTITUTE OF SCIENCE & TECHNOLOGY, DELHI-NCR CAMPUS, MODINAGAR
INDEX
S.No.
Name of Experiment
Date of
Date of
Signature
Execution Submission
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
SRM INSTITUTE OF SCIENCE & TECHNOLOGY, DELHI-NCR CAMPUS, MODINAGAR
21CSC202J - Operating Systems Lab
Exp. No. 1
a) Basics
1. echo SRM
BASIC LINUX COMMANDS
to display the string SRM
2. clear
to clear the screen
3. date
to display the current date and time
4. cal 2003
cal 6 2003
to display the calendar for the year 2003
to display the calendar for the June-2003
5. passwd
to change password
b) Working with Files
1. 1s
list files in the present workingdirectory
1s —1
list files with detailed information (long list)
1s —a
list all files including the hidden files
2. cat > fl
3. cat R
© SRMIST
to create a file (Press ^d to finish typing)
display the content of the file f1
Date :
21CSC202J - Operating Systems Lab
4. wc fl
wc -c fl
wc -w fl
wc -l fl
list no. of characters, words & lines of a file fl
list only no. of characters of filefl
list only no. of words of file f1
list only no. of lines of file fl
5. cp fl f2
copy file fl into f2
6. mv fl f2
rename file fl as f2
7. rm R
remove the file f1
8. head -5fl
tail -5fl
list first 5 lines of the file fl
list last 5 lines of the file fl
c) Working with Directories
1. mkdir elias
to create the directory elias
2. cd elias
to change the directory as elias
3. rmdir elias
to remove the directory elias
to display the path of the present working directory
4. pwd
5. cd
cd ..
cd cd/
© SRMIST
to go to the home directory
to go to the parent directory
to go to the previous working directory
to go to the root directory
21CSC202J - Operating Systems Lab
d) File name substitution
1. 1s f?
list files start with ‘fi and followed by any one character
2. 1s *.c
list files with extension ‘c’
3. 1s [gpy]et
list files whose first letter is any one of the character g, p or
y and followed by the word et
4. 1s [a-d,l-m]ring
list files whose first letter is any one of the character
from a to d and 1 to m and followed by the word ring.
© SRMIST
6-
Exp. No. 2
Process Creation using fork() and usage of getpid(), getppid(),
wait()functions
Date:
1) fork(): The fork() command is a system call in Unix-based OS that creates a new process by
duplicating the calling process. The new process is an exact copy of the parent process, with its own
address space and memory.
Program:
#include <stdio.h>
#include<sys/types.>;
#include<unistd.h>;
int main()
{
// make two process which run same
// program after this
instructionfork();
printf("Hello
world!\n");return 0;
}
2) getppid() : Returns the process ID of the parent of the calling process. If the calling process
was created by the fork() function and the parent process still exists at the time of the getppid
function call, this function returns the process ID of the parent process. Otherwise, this function
returns a value of 1 which is the process id for init process.
Return type: getppid() returns the process ID of the parent of the current process. It never throws
any error therefore is always successful.
getpid() : returns the process ID of the calling process. This is often used by routines that generate
unique temporary filenames.
Return type: getpid() returns the process ID of the current process. It never throws any error
therefore is always successful.
Program:
#include <stdio.h>
#include
<sys/types.h>
#include <unistd.h>
int main()
{
pid_t p;
p = fork();
if(p==-1)
{
printf("There is an error while calling fork()\n");
}
if(p==0)
{
printf("We are in the child process\n");
}
else
{
printf("We are in the parent process\n");
}
return 0;
}
3) wait() system call.
wait() system call will force a parent process to wait for a child process to stop or terminate.
wait() system call return the pid of the child or -1 for an error.
Syntax of wait system call: int wait(int *status_location)
waitpid() system call is used to wait on particular child process instead of waiting for all the child
process.
Syntax for waitpid(): pid_t waitpid(pid_t pid, int *statloc, int options);
Program:
#include <stdio.h>
#include<stdlib.h>
#include<sys/types.>
#include<sys/wait.h>
#include <unistd.h>
//#include <unistd.h>
int main()
{
pid_t pid=fork(); if(pid==0)
{
printf("child => PPID: %d PID: %d\n", getppid(), getpid()); sleep(6);
exit(EXIT_SUCCESS);
}
else if(pid > 0)
{
printf("parent => PID: %d\n", getpid()); printf("waiting for child process to finish \n"); wait(NULL);
printf("child process finished \n");
}
else
{
printf("unable to create child process\n");
}
return EXIT_SUCCESS;
}