Format-Custom

Format-Custom: Customize Your PowerShell Output

Welcome back to Wahmans Powershell blog! Today, we’re diving into a useful but often underutilized cmdlet: Format-Custom.

From Microsoft: The Format-Custom cmdlet uses a customized view to format the output. This cmdlet is especially handy when you want more control over which properties to display and how objects are structured in the console.

Unlike Format-Table or Format-List, which are designed for tabular or list-based formatting, Format-Custom lets you visualize objects based on their type, giving you deeper insight into the object’s structure.

Example 1 – Basic Usage for Beginners

Let’s begin by displaying information about a process using Get-Process.

Get-Process | Format-Custom

This gives a deeply structured view of all properties for each object in Get-Process.

Example 2 – Select Specific Properties

You can limit what gets shown using Select-Object before piping to Format-Custom:

Get-Process | 
  Select-Object Name, Id, CPU | 
  Format-Custom

This will show you only the Name, Id, and CPU properties in a customized layout.

Example 3 – Use with Custom Objects

Here’s how you can use Format-Custom with your own custom object type:

$person = [PSCustomObject]@{
    FirstName = 'John'
    LastName = 'Doe'
    Age = 30
    Occupation = 'Engineer'
}

$person | Format-Custom

This gives you a flexible view of your custom data structure.

Example 4 – Advanced Use with Types.ps1xml

For advanced scenarios, you can define custom views using a types.ps1xml file:

# Suppose you create a types.ps1xml file that defines a custom view for your object
Update-TypeData -AppendPath ".\MyTypes.types.ps1xml"

Get-MyCustomObject | Format-Custom

This lets you control how the object appears every time it’s displayed, ensuring consistency across scripts and sessions.

Conclusion

Format-Custom may not be as flashy as other formatting cmdlets, but it’s a powerful tool for understanding object structures and tailoring output to your needs.

Happy scripting, and I will see you in the next post!