Windows PowerShell

Introduction

This is the content list of this article:

Indroduction
A - What is PowerShell
- Command-line Shell
- Scripting language
- Automation platform
- Configuration management
B - The Windows PowerShell ISE
- Key Features
- Elements
C - Cmdlets
D - Scripting
- How To Run A PowerShell Script
E - Difference Between Command prompt and PowerShell

A - What is PowerShell? [ref]

PowerShell is a cross-platform task automation solution made up of

a command-line shell,
a scripting language, and
a configuration management framework.

PowerShell runs on Windows, Linux, and macOS.

Command-line Shell
PowerShell is a modern command shell that includes the best features of other popular shells. Unlike most shells that only accept and return text, PowerShell accepts and returns .NET objects. The shell includes the following features:
- Robust command-line history
- Tab completion and command prediction (See about_PSReadLine)
- Supports command and parameter aliases
- Pipeline for chaining commands
- In-console help system, similar to Unix man pages
Scripting language
As a scripting language, PowerShell is commonly used for automating the management of systems. It is also used to build, test, and deploy solutions, often in CI/CD environments. PowerShell is built on the .NET Common Language Runtime (CLR). All inputs and outputs are .NET objects. No need to parse text output to extract information from output. The PowerShell scripting language includes the following features:
- Extensible through functions, classes, scripts, and modules
- Extensible formatting system for easy output
- Extensible type system for creating dynamic types
- Built-in support for common data formats like CSV, JSON, and XML
Automation platform
The extensible nature of PowerShell has enabled an ecosystem of PowerShell modules to deploy and manage almost any technology you work with. For example:
- Microsoft
  - Azure
  - Windows
  - Exchange
  - SQL
- Third-party
  - AWS
  - VMWare
  - Google Cloud
Configuration management
PowerShell Desired State Configuration (DSC) is a management framework in PowerShell that enables you to manage your enterprise infrastructure with configuration as code. With DSC, you can:
- Create declarative configurations and custom scripts for repeatable deployments
- Enforce configuration settings and report on configuration drift
- Deploy configuration using push or pull models

B - The Windows PowerShell ISE

Windows PowerShell ISE (Integrated Scripting Environment) is a GUI tool for building and debugging PowerShell scripts, functions, and modules.

Key Features

Multiline editing: To insert a blank line under the current line in the Command pane, press SHIFT+ENTER.
Selective execution: To run part of a script, select the text you want to run, and then click the Run Script button. Or, press F5.
Context-sensitive help: Type Invoke-Item, and then press F1. The Help file opens to the article for the Invoke-Item cmdlet.

The Windows PowerShell ISE lets you customize some aspects of its appearance. It also has its own Windows PowerShell profile script.

Elements

Menu bar
Toolbar
PowerShell tabs
Script tabs
Console pane
Script pane
Status bar
Text-size slider

from How to use Windows PowerShell ISE - Beginners Tutorial (thewindowsclub.com)

These elements make it easy for a user to run, edit, and execute the commands and scripts.

C - Cmdlets

PowerShell commands are known as cmdlets.

Here are 25 basic PowerShell comlets,

Command name	Alias	Description
Set-Location	cd, chdir, sl	Sets the current working location to a specified location.
Get-Content	cat, gc, type	Gets the content of the item at the specified location.
Add-Content	ac	Adds content to the specified items, such as adding words to a file.
Set-Content	sc	Writes or replaces the content in an item with new content.
Copy-Item	copy, cp, cpi	Copies an item from one location to another.
Remove-Item	del, erase, rd, ri, rm, rmdir	Deletes the specified items.
Move-Item	mi, move, mv	Moves an item from one location to another.
Set-Item	si	Changes the value of an item to the value specified in the command.
New-Item	ni	Creates a new item.
Start-Job	sajb	Starts a Windows PowerShell background job.
Compare-Object	compare, dif	Compares two sets of objects.
Group-Object	group	Groups objects that contain the same value for specified properties.
Invoke-WebRequest	curl, iwr, wget	Gets content from a web page on the Internet.
Measure-Object	measure	Calculates the numeric properties of objects, and the characters, words, and lines in string objects, such as files …
Resolve-Path	rvpa	Resolves the wildcard characters in a path, and displays the path contents.
Resume-Job	rujb	Restarts a suspended job
Set-Variable	set, sv	Sets the value of a variable. Creates the variable if one with the requested name does not exist.
Show-Command	shcm	Creates Windows PowerShell commands in a graphical command window.
Sort-Object	sort	Sorts objects by property values.
Start-Service	sasv	Starts one or more stopped services.
Start-Process	saps, start	Starts one or more processes on the local computer.
Suspend-Job	sujb	Temporarily stops workflow jobs.
Wait-Job	wjb	Suppresses the command prompt until one or all of the Windows PowerShell background jobs running in the session are …
Where-Object	?, where	Selects objects from a collection based on their property values.
Write-Output	echo, write	Sends the specified objects to the next command in the pipeline. If the command is the last command in the pipeline,…

from Windows PowerShell Commands Cheat Sheet (PDF), Tips & Lists (comparitech.com)

D - Scripting

A script is a plain text file that contains one or more PowerShell commands. PowerShell scripts have a .ps1 file extension.

How To Run A PowerShell Script

There are two main ways to make a PowerShell script:

The first, which will be familiar if you’ve used Windows Command Line before, is to write scripts directly in notepad. For example, open a new notepad file, and write

Write-Host “Hello World!”

Then save this file as FirstScript.ps1. You can call the script from PowerShell using the command,

& "X:\FirstScript.ps1" And you’ll see the output in PowerShell.
The second, much more powerful way of making PowerShell scripts is to use the Windows PowerShell Integrated Scripting Environment (ISE). With ISE, you can run scripts and debug them in a GUI environment.

E - Difference Between Command prompt and PowerShell

Command prompt, also known as CMD, is a default interpreter in the Windows operating system and was first released in 1987.

The table below will present a comparative analysis of the Windows PowerShell and Windows Command Prompt

PowerShell is an object-oriented task automation engine and scripting language that assists the administrator to automate and configure administrative tasks. On the other hand, the command prompt is a native application in the Windows operating system that allows the user to perform different tasks using the commands.

Reference

Introduction

A - What is PowerShell? [ref]

Command-line Shell

Scripting language

Automation platform

Configuration management