Introduction to CMD

What is a terminal?

A terminal is a user interface that allows interaction with a computer system (operating system) via textual commands. Unlike a graphical user interface (GUI), a terminal receives commands manually entered by the user and returns text in response.

Terminals generally offer:

• Direct access to system management.
• Automation of repetitive tasks.
• Quick system troubleshooting.

History and differences between CMD and PowerShell

Windows offers two main command interpreters: CMD and PowerShell.

CMD

CMD (Command Prompt), also called "Command Prompt" in French, is the standard command interpreter on Windows since MS-DOS.

• Origin: directly derived from MS-DOS.
• Simple language based on predefined commands.
• Ideal for basic scripts and backward compatibility.

PowerShell

PowerShell is a modern shell developed by Microsoft to address the shortcomings of CMD.

• Origin: Introduced with Windows Vista in 2006.
• Based on .NET Framework, supporting complex and object-oriented commands.
• Uses cmdlets (command-lets) for increased flexibility.

Why choose CMD or PowerShell?

• CMD: simple scripts, quick compatibility, and basic tasks.
• PowerShell: complex tasks, advanced automation, and system administration.

CMD: Syntax and essential commands

General syntax

command [options] [arguments]

Frequent commands

Here is a list of the most common commands in CMD:

Command	Description
dir	Lists files and directories
cd	Changes the current directory
copy	Copies a file
move	Moves a file
del	Deletes a file
mkdir	Creates a directory
rmdir	Deletes an empty directory
type	Displays the content of a text file
echo	Displays text
set	Displays or sets environment variables
cls	Clears the screen

Examples

List files:

dir

Change directory:

cd C:\Users\Haythem\Documents

Copy a file:

copy fichier1.txt fichier2.txt

Options in CMD: Using the / character

Unlike Unix/Linux terminals (like bash) where command options are indicated by a dash - or double dash --, CMD traditionally uses the slash / character.

For example, in Bash (Linux or Mac):

ls -l -a

But in CMD (Windows):

dir /w /p

Example of CMD commands with options:

CMD Command	Meaning of the option
dir /w	Display files and directories in wide format (columns).
dir /p	Display files page by page, pausing.
copy /y	Copy a file without asking for confirmation to overwrite.
del /q	Delete files without confirmation.
taskkill /IM notepad.exe	Terminate a specific application (IM means Image Name).

Getting help on commands (/ ?)

Unlike Unix or Bash, where the --help option provides help on a command, the equivalent in CMD is to use the /? option.

General syntax:

command /?

This command displays a detailed description as well as the different options available for a specific command.

Example:

To get help for the dir command, type:

dir /?

CMD Variables

A CMD variable is a temporary reference allowing storage of information or values that can be used later in the same CMD session or in a batch script.

• Syntax:

set variable_name=value

• Simple example:

set utilisateur=Haythem
echo Bonjour %utilisateur%

By default, variables defined with the set command in a CMD instance are not visible in another simultaneously opened instance. Each CMD instance maintains its own variables independently of others. To create a permanent environment variable (which will be visible to all new CMD sessions), you must use the Windows control panel or the setx utility:

setx utilisateur Haythem

Batch scripts (.bat)

Batch files allow automation of repetitive tasks.

Complete example:

Create a file named backup.bat:

@echo off
echo Starting backup...

set source=C:\Users\Haythem\Documents\Important
set destination=D:\Backup\Documents\Important

if not exist %destination% mkdir %destination%

copy %source%\*.txt %destination%

echo Backup completed.
pause

Running batch scripts

• Double-click on the .bat file.
• From CMD: backup.bat.

References

There are many resources to learn how to write batch scripts, including the official Microsoft documentation and other online tutorials like tutorialspoint.

Advanced manipulation with CMD

Redirection

• >: sends output to a file.
• >>: appends to an existing file.

Example:

dir > liste_fichiers.txt

Pipes (|)

Allows sending the output of one command to another.

dir | find "rapport"

Task management

List processes:

tasklist

Terminate a process:

taskkill /IM notepad.exe

Network management

Display network information:

ipconfig

Check network connection:

ping google.com

Conclusion

CMD is an essential tool for Windows users looking to quickly automate simple tasks. Despite its limitations compared to PowerShell, its simplicity and speed make it a good choice for common tasks and simple scripts.