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

Anchors


An anchor does not match a character; instead, it matches what comes before (or after) a character:

Description

Character

Example

Beginning of a string

^

'aba' -match '^a'

End of a string

$

'cbc' -match 'c$'

Word boundary

\b

'Band and Land' -match '\band\b'

Anchors are useful where a character, string, or word may appear elsewhere in a string and the position is critical.

For example, there might be a need to get values from the PATH environment variable that starts with a specific drive letter. One approach to this problem is to use the start of a string anchor, in this case, retrieving everything that starts with the C drive:

$env:PATH -split ';' | Where-Object { $_ -match '^C' }

Alternatively, there may be a need to get every path three or more directories deep from a set:

$env:PATH -split ';' | Where-Object { $_ -match '\\.+\\.+\\.+$' }

The word boundary matches both before and after a word. It allows a pattern to look for a specific word, rather than a string of characters that may be a word...