The PowerShell Best Practices and Style Guide

Table Of Contents

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License, please attribute to Don Jones, Matt Penny, Carlos Perez, Joel Bennett and the PowerShell Community.

You are free to:

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The authors encourage you to redistribute this content as widely as possible, but require that you give credit to the primary authors below, and that you notify us on GitHub of any improvements you make.

What are Best Practices

PowerShell Best Practices are what you should usually do as a starting point. They are ways of writing, thinking, and designing which make it harder to get into trouble. The point of a Best Practice is to help the reader to fall into the pit of success:

The Pit of Success: in stark contrast to a summit, a peak, or a journey across a desert to find victory through many trials and surprises, we want our customers to simply fall into winning practices by using our platform and frameworks. To the extent that we make it easy to get into trouble we fail.

-- Rico Mariani, MS Research MindSwap Oct 2003.

Like English spelling and grammar rules, PowerShell programming best practices and style rules nearly always have exceptions, but we are documenting a baseline for code structure, command design, programming, formatting, and even style which will help you to avoid common problems, and help you write more reusable, readable code -- because reusable code doesn't have to be rewritten, and readable code can be maintained.

Having said that, remember: the points in the Best Practices documents and the Style Guide are referred to as practices and guidelines, not rules. If you're having trouble getting something done because you're trying to avoid breaking a style or best practice rule, you've misunderstood the point: this document is pragmatic, rather than dogmatic. We'll leave dogmatism to teams and projects that require you to meet their specific guidelines.

Table of Contents

The guidelines are divided into these sections:

• Style Guide (Introduction)
  • Code Layout and Formatting
  • Function Structure
  • Documentation and Comments
  • Readability
  • Naming Conventions
• Best Practices (Introduction)
  • Naming Conventions
  • Building Reusable Tools
  • Output and Formatting
  • Error Handling
  • Performance
  • Security
  • Language, Interop and .NET
  • Metadata, Versioning, and Packaging

Current State:

Remember what we mean by Best Practices.

The PowerShell Best Practices are always evolving, and continue to be edited and updated as the language and tools (and our community understanding of them) evolve. We encourage you to check back for new editions at least twice a year, by visiting https://github.com/PoshCode/PowerShellPracticeAndStyle.

The PowerShell Style Guide in particular is in PREVIEW, and we are still actively working out our disagreements about the rules in the guide through the GitHub issues system.

Contributing

Please use the issues system or GitHub pull requests to make corrections, contributions, and other changes to the text - we welcome your contributions!

For more information, see CONTRIBUTING.

Credits

The Community Book of PowerShell Practices was originally compiled and edited by Don Jones and Matt Penny with input from the Windows PowerShell community on PowerShell.org.

Portions copyright (c) Don Jones, Matt Penny, 2014-2015

The PowerShell Style Guide was originally created by Carlos Perez, for his students, and all the good parts were written by him.

Portions copyright (c) Carlos Perez, 2015

Any mistakes in either of these documents are there because Joel Bennett got involved. Please submit issues and help us correct them.

Portions copyright (c) Joel Bennett, 2015