ITI COPA (Computer Operator & Programming Assistant) – Basic Notes

Topic -

Introduction to DOS Command Line Interface & Linux Operating Systems

1. Introduction to DOS Command Line Interface (CLI)

DOS (Disk Operating System) is a single-user, single-tasking operating system that uses a Command Line Interface (CLI). In CLI, the user interacts with the computer by typing commands using the keyboard instead of using a mouse or graphical interface.

Command Line Interface (CLI)

A Command Line Interface allows users to give instructions to the computer by typing commands at a prompt.

Example of DOS prompt:


C:\>

Features of DOS

Text-based interface
Fast execution of commands
Requires less memory
No graphics support
Direct control over system files

Advantages of DOS

Low hardware requirement
Faster for experienced users
Useful for troubleshooting
Better understanding of file structure

Limitations of DOS

No graphical interface
Difficult for beginners
No multitasking
Limited security

2. Introduction to Basic DOS Commands

DOS commands are instructions given to the system to perform tasks like file creation, deletion, copying, etc. DOS commands are classified into Internal Commands and External Commands.

3. DOS Internal Commands

Internal commands are built into the command interpreter (COMMAND.COM). These commands are loaded into memory during booting and are always available.

Common DOS Internal Commands

DIR
- Displays list of files and folders.
- Syntax: DIR
CLS
- Clears the screen.
- Syntax: CLS
COPY
- Copies files from one location to another.
- Syntax: COPY source destination
DEL / ERASE
- Deletes files.
- Syntax: DEL filename
REN / RENAME
- Renames a file.
- Syntax: REN oldname newname
TYPE
- Displays content of a text file.
- Syntax: TYPE filename
DATE
- Displays or changes system date.
TIME
- Displays or changes system time.
CD / CHDIR
- Changes directory.
- Syntax: CD foldername
MD / MKDIR
- Creates a directory.
RD / RMDIR
- Deletes a directory.

4. DOS External Commands

External commands are not part of COMMAND.COM. They are stored as separate files with extensions like .EXE, .COM, or .BAT and must be present on disk to be executed.

Common DOS External Commands

FORMAT
- Formats a disk.
- Syntax: FORMAT A:
CHKDSK
- Checks disk for errors.
DISKCOPY
- Copies entire disk.
XCOPY
- Copies files and directories.
TREE
- Displays directory structure in tree form.
ATTRIB
- Changes file attributes.
EDIT
- Opens text editor.
LABEL
- Changes disk label.

Difference Between Internal and External Commands

Internal Commands	External Commands
Stored in memory	Stored on disk
Always available	Need external file
Faster execution	Slower than internal

5. Introduction to Open Source Software

Open Source Software (OSS) is software whose source code is freely available for users to view, modify, and distribute.

Features of Open Source Software

Free to use
Source code available
Community-driven development
Highly customizable
Secure and reliable

Advantages of Open Source Software

No licensing cost
Transparency
Flexibility
Vendor independence

Examples of Open Source Software

Linux
LibreOffice
Mozilla Firefox
GIMP
Apache

6. Introduction to Linux Operating System

Linux is a free and open-source operating system based on UNIX. It was developed by Linus Torvalds in 1991.

Features of Linux OS

Open source
Multiuser and multitasking
High security
Portable
Stable and reliable
Strong networking support

Advantages of Linux

Free of cost
Low system requirements
Rare virus attacks
Suitable for servers and desktops

7. Structure of Linux Operating System

Linux OS is made up of several layers:

Kernel
- Core of Linux OS.
- Manages CPU, memory, devices, and processes.
Shell
- Interface between user and kernel.
- Interprets commands.
File System
- Organizes data in hierarchical structure.
Utilities and Applications
- Commands and programs for user tasks.

8. Linux File System

Linux follows a tree-like hierarchical file system starting from root /.

Important Linux Directories

/ → Root directory
/home → User home directories
/bin → Essential command binaries
/etc → Configuration files
/usr → User programs
/var → Variable data
/tmp → Temporary files

Features of Linux File System

Case-sensitive
Everything is treated as a file
Supports file permissions

9. Linux Processes

A process is a program in execution.

Types of Processes

Foreground process
Background process
Daemon process

Process Management

Each process has a Process ID (PID)
Managed by kernel
Commands like ps, top, kill

10. Basic Linux Commands

Linux commands are used to perform tasks like file handling, directory navigation, and system monitoring.

Common Linux Commands

pwd
- Shows present working directory.
ls
- Lists files and directories.
cd
- Changes directory.
mkdir
- Creates directory.
rmdir
- Deletes empty directory.
touch
- Creates empty file.
cp
- Copies files.
mv
- Moves or renames files.
rm
- Deletes files.
cat
- Displays file content.
clear
- Clears terminal screen.
ps
- Shows running processes.
top
- Displays real-time process information.
kill
- Terminates a process.

11. Importance of DOS and Linux for COPA Students

Helps understand system internals
Improves troubleshooting skills
Useful for server administration
Foundation for advanced OS concepts
Enhances command-line efficiency

MCQ Questions (30 Questions for CBT Exam)

1. DOS uses which interface?

A) GUI
B) CLI
C) Touch
D) Voice
Ans: B

2. DOS is a:

A) Multiuser OS
B) Multitasking OS
C) Single-user OS
D) Network OS
Ans: C

3. Which symbol shows DOS prompt?

A) /
B) #
C) $
D) >
Ans: D

4. Which is an internal DOS command?

A) FORMAT
B) TREE
C) DIR
D) CHKDSK
Ans: C

5. CLS command is used to:

A) Close file
B) Clear screen
C) Copy file
D) Create folder
Ans: B

6. Which command deletes a file in DOS?

A) COPY
B) DEL
C) REN
D) TYPE
Ans: B

7. FORMAT is a:

A) Internal command
B) External command
C) Kernel command
D) Shell command
Ans: B

8. Open source software means:

A) Paid software
B) Source code hidden
C) Source code available
D) Trial software
Ans: C

9. Linux is developed by:

A) Bill Gates
B) Steve Jobs
C) Linus Torvalds
D) Dennis Ritchie
Ans: C

10. Linux is based on:

A) DOS
B) UNIX
C) Windows
D) Android
Ans: B

11. Which is the core of Linux OS?

A) Shell
B) Kernel
C) Terminal
D) File system
Ans: B

12. Root directory in Linux is:

A) /home
B) /root
C) /
D) /bin
Ans: C

13. Which command shows current directory?

A) ls
B) pwd
C) cd
D) dir
Ans: B

14. Linux file system is:

A) Flat
B) Linear
C) Hierarchical
D) Circular
Ans: C

15. Which command lists files in Linux?

A) dir
B) list
C) show
D) ls
Ans: D

16. mkdir command is used to:

A) Delete directory
B) Rename directory
C) Create directory
D) Move directory
Ans: C

17. Which command removes a file in Linux?

A) del
B) erase
C) rm
D) removefile
Ans: C

18. Linux is a ______ OS.

A) Proprietary
B) Open source
C) Trial
D) Closed
Ans: B

19. Which directory stores configuration files?

A) /bin
B) /home
C) /etc
D) /tmp
Ans: C

20. Shell acts as:

A) Hardware
B) Interface
C) Memory
D) Virus
Ans: B

21. Which command clears Linux screen?

A) cls
B) clear
C) clean
D) erase
Ans: B

22. Process ID is known as:

A) UID
B) GID
C) PID
D) SID
Ans: C

23. Which command shows running processes?

A) ls
B) pwd
C) ps
D) kill
Ans: C

24. Which command terminates a process?

A) stop
B) end
C) kill
D) exit
Ans: C

25. Linux is case:

A) Insensitive
B) Sensitive
C) Neutral
D) Ignored
Ans: B

26. External commands are stored:

A) In RAM
B) In ROM
C) On disk
D) In kernel
Ans: C

27. Which Linux command copies files?

A) move
B) copy
C) cp
D) xcopy
Ans: C

28. Which is an example of OSS?

A) MS Word
B) Windows
C) Linux
D) Photoshop
Ans: C

29. touch command is used to:

A) Open file
B) Delete file
C) Create empty file
D) Rename file
Ans: C

30. Linux supports:

A) Single user
B) Single task
C) Multiuser
D) No user
Ans: C

ITI (Trade - COPA) Day-8