Windows PowerShell Explained: Commands, Scripting, and System Automation

Windows PowerShell is a task-based command-line shell and scripting language that was designed specifically for system administrators. Developed by Microsoft, it is built on the .NET Framework and helps IT professionals control and automate the administration of Windows operating systems and applications. With the evolution of computing, PowerShell has grown beyond just Windows and now supports cross-platform usage, making it a vital tool in modern IT environments.

PowerShell provides a powerful interface for managing computers through scripts and cmdlets—lightweight commands that perform specific tasks. Its object-oriented approach sets it apart from traditional shells, enabling users to manipulate data in the form of .NET objects.

What is PowerShell

PowerShell was introduced in 2006 to provide a more robust and flexible alternative to the traditional Command Prompt. Unlike older shells, PowerShell works with objects, not text, which means data output from one command can be directly passed into another without conversion.

At its core, PowerShell includes a rich expression parser and a fully developed scripting language. It supports conditionals, loops, functions, and more, making it a capable tool for writing complex automation scripts. Because of its integration with Windows and its ability to tap into the Windows Management Instrumentation (WMI), it allows deep system-level administration.

Today, PowerShell is not just limited to Windows. With the introduction of PowerShell Core and later PowerShell 7, it is now a cross-platform solution that supports Windows, macOS, and Linux.

PowerShell 7

PowerShell 7 represents a significant leap forward in PowerShell’s development. It is based on .NET Core, making it compatible with multiple operating systems. This version is often referred to as PowerShell Core, and it replaces Windows PowerShell 5.1 as the actively developed and supported edition.

PowerShell 7 introduces several enhancements, including:

• Improved performance and start-up time
• Pipeline parallelization with the ForEach-Object -Parallel parameter
• New operators like the ternary operator (? :) and null coalescing operators (??, ??=)
• Compatibility with many existing Windows PowerShell modules

Because of these features, PowerShell 7 is recommended for users who need modern capabilities and cross-platform support. It’s especially popular among DevOps engineers and developers working in hybrid cloud environments.

Also Read: What is a Program Manager? A Complete Guide

Check PowerShell Version

Before you start using advanced features or writing scripts that depend on specific functionalities, it’s essential to check the version of PowerShell installed on your system. This ensures compatibility with your scripts or modules.

To check the PowerShell version, open a PowerShell session and type the following command:

powershellCopyEdit$PSVersionTable.PSVersion

This will output the version information in a structured format, typically displaying the major, minor, build, and revision numbers. If you’re still running Windows PowerShell 5.1, you might consider upgrading to PowerShell 7 for better performance and cross-platform support.

Find PowerShell Version Programmatically

In some scenarios, especially during deployment or scripting tasks, you might need to programmatically find the PowerShell version to determine if a certain script can run. Here’s a simple way to do that:

powershellCopyEditif ($PSVersionTable.PSVersion.Major -ge 7) {
    Write-Output "PowerShell 7 or newer is installed."
} else {
    Write-Output "Older version of PowerShell is installed."
}

This script checks the major version number and responds accordingly, allowing you to take conditional actions based on the installed version.

How to Update PowerShell

Keeping your PowerShell installation up to date is important for security, functionality, and performance. The update process differs slightly depending on your operating system.

On Windows, you can update PowerShell via the Microsoft Store (if available), or more commonly by downloading the latest installer from the official GitHub releases page:

1. Go to the PowerShell GitHub repository: https://github.com/PowerShell/PowerShell
2. Download the installer for your OS (e.g., .msi for Windows)
3. Run the installer and follow the on-screen instructions

On macOS or Linux, PowerShell can be updated using a package manager like Homebrew or APT/YUM, depending on the distribution.

Example for macOS:

bashCopyEditbrew update
brew upgrade --cask powershell

Example for Ubuntu Linux:

bashCopyEditsudo apt-get update
sudo apt-get install --only-upgrade powershell

Always restart your terminal after updating to ensure that the new version is active.

Can You Use Linux on PowerShell

One of the standout features of newer PowerShell versions is their support for Linux. With PowerShell 7, you can install and run PowerShell natively on various Linux distributions, including Ubuntu, CentOS, Debian, and Fedora.

While the command set is largely the same across platforms, certain Windows-specific cmdlets may not be available on Linux. However, many Linux system administration tasks—such as managing processes, services, files, and users—can be accomplished directly from PowerShell.

For example, you can list all active processes on a Linux machine using:

powershellCopyEditGet-Process

You can even invoke native Linux commands within PowerShell:

powershellCopyEditls -la

PowerShell on Linux also supports remote sessions, scripting, and modules, making it a viable choice for cross-platform system automation.

PowerShell Commands You Should Know

PowerShell offers a vast library of commands, known as cmdlets. These follow a Verb-Noun naming convention, which makes them easy to understand and remember.

Here are some fundamental PowerShell commands:

• Get-Help: Provides help for cmdlets and scripts
• Get-Command: Lists all available commands
• Get-Process: Displays a list of running processes
• Start-Service / Stop-Service: Manages services
• Get-EventLog: Retrieves event logs
• Set-ExecutionPolicy: Sets script execution permissions
• Get-ChildItem: Lists items in a directory (similar to ls or dir)
• Copy-Item, Move-Item, Remove-Item: File and folder operations

These commands form the building blocks of most PowerShell scripts and can be extended with parameters, piping, and logic for more complex tasks.

How to Run PowerShell Script

Running scripts is one of the most powerful capabilities of PowerShell. Scripts allow you to automate repetitive tasks, set up systems, and even deploy applications.

To run a PowerShell script, save it with the .ps1 extension. For example, myscript.ps1.

By default, PowerShell restricts the execution of scripts to prevent malicious activity. You can change this setting using:

powershellCopyEditSet-ExecutionPolicy RemoteSigned

Then run your script by navigating to its location and executing:

powershellCopyEdit.\myscript.ps1

On Linux or macOS, make sure the script has executable permissions:

bashCopyEditchmod +x myscript.ps1
pwsh ./myscript.ps1

Using proper execution policies and user permissions helps ensure secure script execution.

PowerShell Functions

Functions in PowerShell help break complex scripts into manageable and reusable blocks of code. They are defined using the function keyword.

Here’s a basic example of a PowerShell function:

powershellCopyEditfunction Get-Greeting {
    param (
        [string]$Name
    )
    return "Hello, $Name!"
}

Get-Greeting -Name "Alice"

Functions can accept parameters, include internal logic, and return data. They help improve code readability, modularity, and maintainability. Functions are often stored in modules for reuse across multiple scripts or environments.

PowerShell Set Environment Variable

Setting environment variables is a common need when configuring systems or preparing environments for specific applications.

To set an environment variable in PowerShell:

powershellCopyEdit$env:MY_VARIABLE = "MyValue"

To verify that the variable has been set:

powershellCopyEditecho $env:MY_VARIABLE

This sets the variable for the current session. If you want to set it permanently (system-wide or for the user), you can use the .NET class:

powershellCopyEdit[System.Environment]::SetEnvironmentVariable("MY_VARIABLE", "MyValue", "User")

You can also change User to Machine to set it system-wide, which typically requires administrator privileges.

Advanced PowerShell Capabilities

Beyond the basics, PowerShell supports advanced features that can take your automation and system management to the next level. These include:

• Remote Management via PowerShell Remoting (Invoke-Command, Enter-PSSession)
• Desired State Configuration (DSC) for infrastructure automation
• PowerShell Modules to package and distribute functions and scripts
• Background jobs and scheduled tasks for asynchronous operations
• Custom object manipulation and data formatting for reporting

Mastering these capabilities allows you to create highly reliable and reusable solutions for enterprise-scale environments.

Conclusion

Windows PowerShell has grown from a Windows-only shell into a versatile, cross-platform automation tool. Whether you’re managing systems, developing DevOps pipelines, or automating repetitive tasks, PowerShell offers a powerful suite of features to help you get the job done.

By learning to check and update your version, understanding the core commands, and exploring its scripting potential, you unlock the full power of this remarkable tool. With PowerShell 7, you also gain access to a modern, fast, and extensible environment that works across Windows, macOS, and Linux.

For both beginners and advanced users, investing time into learning PowerShell can yield significant productivity and operational benefits.

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