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

Error action


The ErrorAction parameter and the ErrorActionPreference variable are used to control what happens when a non-terminating error is written.

Note

CmdletBinding:The ErrorAction parameter is only available if a function declares the CmdletBinding attribute. CmdletBinding is automatically added is automatically added if the Parameter attribute is used.

By default, the ErrorAction is set to continue. Any non-terminating errors will be displayed, but a script or function will continue to run.

If the ErrorAction is set to SilentlyContinue, errors will be added to the automatic variable $error, but the error will not be displayed.

The following function writes a non-terminating error using Write-Error:

function Invoke-Something { 
    [CmdletBinding()] 
    param ( ) 
 
    Write-Error 'Something went wrong' 
} 
Invoke-Something-ErrorAction SilentlyContinue 

The error is written, but hidden from view. The error may be viewed as the latest entry in the $error variable:

PS> $Error[0]
Invoke...