Mastering PowerShell Get-Command: A Comprehensive Guide with Code Examples

Introduction:

PowerShell is a powerful automation and scripting language that offers a plethora of commands and functions. Among these, the Get-Command cmdlet stands out as a versatile tool that helps sysadmins discover, explore, and interact with all available commands. In this blog post, we’ll take a deep dive into the Get-Command cmdlet, exploring its features and providing detailed code examples to help you harness its full potential.

What is Get-Command?

The Get-Command cmdlet in PowerShell is used to retrieve information about available commands within the current session. It can be employed to discover cmdlets, functions, scripts, and executable files. Understanding how to use Get-Command effectively is essential for sysadmins, as it allows you to tap into the vast repository of PowerShell commands at your disposal.

Basic Usage of Get-Command:

Syntax:

Get-Command [-Name] <String> [-Verb <String>] [-Noun <String>] [-Module <String[]>] [-CommandType <CmdletType>]

• Name: Specifies the name of the command you want to retrieve.
• Verb: Filters commands based on the verb (e.g., Get, New, Set).
• Noun: Filters commands based on the noun (e.g., Process, Service, Item).
• Module: Limits the search to specific modules.
• CommandType: Filters commands based on their type (Cmdlet, Function, Script, Application, ExternalScript).

Practical Code Examples:

Example 1: Listing All Available Commands

Get-Command

This command will return a list of all available cmdlets, functions, and scripts in your PowerShell session.

Example 2: Finding Commands by Verb

Get-Command -Verb Get

This will display a list of all commands with the verb “Get,” helping you quickly find retrieval commands.

Example 3: Finding Commands by Noun

Get-Command -Noun Service

This will display a list of all options with the Noun “Service,” helping you quickly find retrieval commands.

Example 4: Searching for a Specific Command

Get-Command -Name Get-Service

This command provides information about the “Get-Service” cmdlet, including its name, definition, and module.

Example 5: Filtering by Module

Get-Command -Module ActiveDirectory

This retrieves all commands that belong to the “ActiveDirectory” module.

Example 6: Differentiating Command Types

Get-Command -CommandType Function

Here, we filter and list only functions available in your session.

Advanced Techniques:

Discovering Command Aliases

Get-Command -Name gci

This example reveals that the “gci” command is an alias for “Get-ChildItem.”

Sorting and Formatting

Get-Command | Sort-Object Name | Format-Table Name, CommandType -AutoSize

This code sorts the commands alphabetically and formats them into a table, displaying only the name and command type.

Conclusion:

The Get-Command cmdlet in PowerShell is a fundamental tool for sysadmins and anyone working with PowerShell. It empowers you to explore and understand the available commands in your environment, enabling more efficient scripting and automation. By mastering the usage of Get-Command with the provided code examples, you can become a more proficient PowerShell user and sysadmin.

In future blog posts, we’ll delve deeper into other PowerShell cmdlets and provide practical use cases to enhance your skills as a sysadmin.

Remember, practice makes perfect. Experiment with Get-Command and discover the wealth of PowerShell commands at your disposal.