Introduction

Windows PowerShell is a scripting language and automation engine that is designed using object-oriented concepts with the .NET framework. It provides a Graphical User Interface (GUI) and command line components to manipulate servers and workstations using a scripting language that offers easy syntax. PowerShell works simply by invoking cmdlets and scripts locally or remotely. PowerShell uses the background Intelligent Transfer Service (BITS) to transfer files between machines in an asynchronized and prioritized manner.

PowerShell has several advantages, including the ability to execute powerful scripts to accomplish tasks that cannot be executed using a few lines of code. Further, PowerShell variables can hold output from values, commands, and objects, and it is not necessary to specify the type of a particular variable.

PowerShell holds advantages over the traditional command line interface in several respects. First, it is integrated with the Windows operating system and provides a scripting language and interactive command line interface to execute scripts. On the other hand, the command line interface is a simple Win32 application provided by Microsoft, and it can interact with any Win32 application. Cmdlets used in PowerShell are not available through the command prompt and can be invoked by the automation scripts or the runtime environment. Cmdlets in PowerShell are treated as objects, and this provides the flexibility to use them anywhere else by passing them as input to another cmdlet. This feature is only specific to PowerShell, which also consists of several other capabilities, features, and functions that are not available in the command prompt with only very basic functionality.

PowerShell is increasingly becoming the preferred scripting platform for IT administrators as it supports management operations in large corporate networks containing as many as four hundred servers. Functions, like executing security solutions that require a script to be constantly running in the background, can be accomplished with PowerShell scripting. It allows comprehensive functionality, including the ability to login to multiple servers to check whether a specific service is installed and running. These otherwise time-consuming operations can be completed in much less time and limit human error as the time spent doing non-productive processes is minimized. Tasks can be completed in only a few minutes as scripts may be used to complete operations related to services executing on multiple servers.

These are just a few examples of the benefits and features of PowerShell. Throughout the following chapters we will take a deep dive into PowerShell scripting and discuss in more detail how to use PowerShell effectively. Let’s begin!

Chapter One:  What is Windows PowerShell

PowerShell is a task automation solution that works across platforms. It helps automate tasks in the Windows ecosystem and simplifies configuration, like exchange and active directory. It has the capability to handle large file batches, assist in setting up new machines, control access to large file volume, and automate the tasks related to adding network drives, taking backups, updating security software, and granting users access to shared files.

The most frequent automation tasks performed using PowerShell are working with file batches to control access to a large number of files and automate backups, adding and removing new users, updating security software, adding network drives, granting access to shared files, displaying the USB devices on computers on a network, setting an elaborate task to run as a background process, terminating non-responsive processes, and filtering information about computers in a network for exporting it in HTML format.

PowerShell consists of a scripting language, configuration management framework, and command-line shell. Compatible with macOS, Windows, and Linux, it is a high-level programming language developed by Microsoft to automate configurations and actions.

The Command Shell

The command shell in PowerShell is unlike any other platform. While most shells accept and return text, PowerShell returns .NET objects. The shell consists of a number of features: command and parameter aliases, pipeline for chaining commands, in-console help system, command prediction, tab completion, and a robust command-line history.

The Scripting Language

PowerShell can be used as a scripting language to automate the management of systems and to deploy solutions in continuous integration/continuous delivery (CI/CD) environments. PowerShell scripting language is fully extensible with its classes, modules, scripts, and functions. Its formatting system is also extensible and gives easy access to output. An extensible type system helps to create dynamic types. Further,