Operating Systems Lab (PCC-CS592)

This repository contains all of my codes from the course Operating Systems Laboratory (PCC-CS592) which was a part of our 5th Semester B.Tech CSE Curriculum.

• Shell Scripting has been done in Bourne-again Shell (BASH)
• System Programming has been done in C Langauge
• Apart from bash, Assignment-4 will involve writing awk scripts as well.

The syllabus is broadly divided into 2 parts: 1. Shell Scripting and 2. System Programming (Inter-Process Communication(IPC), Process and Thread Management).

Instructions for Users:

Basic Vim Customization:

To make your experience with Vim better you may add the following lines to your .vimrc file located at /home/<your_username>. It is a hidden file and to view it you must use ls -a command. The commands are:

set autoindent
set smartindent
set number
set mouse=a

I have also added this sample .vimrc file that you can copy/paste.

Running Shell Scripts from the terminal:

To run your bash scripts from the terminal, either change the permissions first, i.e. assign execute permission to the user using the chmod command or run directly using the bash command. For example:

chmod u+x <my_script_name>.sh

and then run using:

./<my_script_name>.sh

OR

Simply run using:

bash <my_script_name>.sh

To run awk scripts, use the commmand

awk -f <my_script_name>.awk input_file

Running the C codes:

To compile C programs from the terminal which use the library pthread.h to deal with semaphores:

gcc <my_C_program_name>.c -lpthread -o <executable_name>

For general C programs:

 gcc <my_C_program_name>.c -o <executable_name>

To run:

./<executable_name>

To run in the background (This enables you to have access to the terminal while the process is running the background):

./<executable_name> &

This will be particularly useful to check for Zombie processes because you will be required to run the ps -f f command while one of the processes is still in execution.

Important Header Files for System Programming

I have listed all the important header files that are particularly important for running the programs in this course:

#include<stdio.h>
#include<stdlib.h>
#include<stdbool.h>
#include<unistd.h>
#include<fcntl.h>
#include<semaphore.h>
#include<pthread.h>
#include<sys/wait.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<signal.h>