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

Raising errors


When writing a script, it may be desirable to use errors to notify someone running the script of a problem. The severity of the problem might dictate whether an error is non-terminating or terminating.

If a script makes a single change to a large number of diverse, unrelated objects, a terminating error might be frustrating for anyone using the script.

On the other hand, if a script fails to read a critical configuration file, a terminating error is likely the right choice.

Error records

When an error is raised in PowerShell, an ErrorRecord object is created (explicitly or implicitly).

An ErrorRecord object contains a number of fields that are useful for diagnosing an error. An ErrorRecord can be explored using Get-Member. For example, an ErrorRecord will be generated when attempting to divide by 0:

100 / 0 
$record = $Error[0] 

The ErrorRecord that was generated includes a ScriptStackTrace:

PS> $record.ScriptStackTrace
at <ScriptBlock>, <No file>: line 1
As well as...