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

Type operators


The type operators are designed to work with .NET types. The following operators are available:

  • As: -as
  • Is: -is
  • Is not: -isnot

As

The -as operator is used to convert a value into an object of the specified type. The operator returns null (without throwing an error) if the conversion cannot be completed.

For example, the operator may be used to perform the following conversions:

"1" -as [Int32] 
'String' -as [Type] 

The -as operator can be useful for testing whether or not a value can be cast to a specific type, or whether a specific type exists.

For example, the System.Web assembly is not imported by default and the System.Web.HttpUtility class does not exist. The -as operator may be used to test for this condition:

PS> if (-not ('System.Web.HttpUtility' -as [Type])) {
    Write-Host 'Adding assembly' -ForegroundColor Green
    Add-Type -Assembly System.Web
}
Adding assembly

Is and isnot

The -is and -isnot operators test whether or not a value is of the specified type.

For example,...