Book Image

Mastering Windows PowerShell Scripting (Second Edition) - Second Edition

By : Brenton J.W. Blawat
Book Image

Mastering Windows PowerShell Scripting (Second Edition) - Second Edition

By: Brenton J.W. Blawat

Overview of this book

PowerShell scripts offer a handy way to automate various chores. Working with these scripts effectively can be a difficult task. This comprehensive guide starts from scratch and covers advanced-level topics to make you a PowerShell expert. The first module, PowerShell Fundamentals, begins with new features, installing PowerShell on Linux, working with parameters and objects, and also how you can work with .NET classes from within PowerShell. In the next module, you’ll see how to efficiently manage large amounts of data and interact with other services using PowerShell. You’ll be able to make the most of PowerShell’s powerful automation feature, where you will have different methods to parse and manipulate data, regular expressions, and WMI. After automation, you will enter the Extending PowerShell module, which covers topics such as asynchronous processing and, creating modules. The final step is to secure your PowerShell, so you will land in the last module, Securing and Debugging PowerShell, which covers PowerShell execution policies, error handling techniques, and testing. By the end of the book, you will be an expert in using the PowerShell language.
Table of Contents (24 chapters)
Title Page
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Comparing


The Compare-Object command allows collections of objects to be compared to one another.

Compare-Object must be supplied with a value for the ReferenceObject and DifferenceObject parameters, which are normally collections or arrays of objects. If both values are equal, Compare-Object does not return anything by default. For example, both the Reference and Difference object in the following example are identical:

Compare-Object -ReferenceObject 1, 2 -DifferenceObject 1, 2 

If there are differences, Compare-Object will display the results, as shown here:

PS> Compare-Object -ReferenceObject 1, 2, 3, 4 -DifferenceObject 1, 2

InputObject SideIndicator
----------- -------------
          3 <=
          4 <=

This shows that the Reference object (the collection on the left) has the values, but the Difference object (the collection on the right) does not.

Compare-Object has a number of other parameters that may be used to change the output. The IncludeEqual parameter adds values which...