Exploring the PSConsoleHostReadLine Cmdlet in PowerShell

Welcome back to Wahmans PowerShell Blog! Today, we’re diving into a rather hidden gem in the PowerShell ecosystem: PSConsoleHostReadLine.

According to the Microsoft documentation, PSConsoleHostReadLine is the main entry point for PSReadLine. While it’s not a cmdlet you’ll call directly often, understanding its role will help you grasp how PowerShell handles input in the console—and also how you can manipulate or extend it in clever ways.

PSReadLine is the module responsible for how the command-line interface feels: command history, syntax highlighting, auto-completion, keyboard shortcuts, and more. PSConsoleHostReadLine is the internal function that gets called every time the console needs input from you.

So, why should you care?

While PSConsoleHostReadLine itself isn’t often used directly, understanding it can help you:

• Customize or troubleshoot your console experience
• Write advanced scripts that integrate deeply with the PSReadLine layer
• Interact more effectively with PowerShell’s interactive session behavior

Let’s explore some examples that show off its utility—from beginner to more advanced uses.

Example 1: Discovering the Function Definition

Curious to see what’s behind PSConsoleHostReadLine? Use this command to output the definition:

Get-Command -Name PSConsoleHostReadLine | Select-Object -ExpandProperty Definition

This shows you the internal function definition, which is helpful when learning how PSReadLine works under the hood.

Example 2: Viewing Bound Key Handlers

You can list all keyboard shortcuts currently bound to readline functions:

Get-PSReadLineKeyHandler

Although this command doesn’t call PSConsoleHostReadLine directly, it interacts with the layer controlled by it.

Example 3: Custom Keybinding to Call Custom ReadLine Function

Let’s say you want to intercept input differently. You can override the behavior of PSReadLine by registering your own function:

function MyCustomReadLine {
    Write-Host "Custom ReadLine Triggered"
    [Microsoft.PowerShell.PSConsoleReadLine]::ReadLine()
}

Set-PSReadLineKeyHandler -Key Ctrl+Shift+R -ScriptBlock ${function:MyCustomReadLine}

Pressing Ctrl+Shift+R in your console will now trigger your custom input reader!

Example 4: Simulating Interactive Input in a Constrained Language Mode

In constrained language mode, the console may restrict input methods. By calling PSConsoleHostReadLine explicitly via reflection, you can sometimes bypass limitations (use with caution and only in secure environments):

$method = [Microsoft.PowerShell.PSConsoleReadLine]::GetMethod("ReadLine", [System.Reflection.BindingFlags]"NonPublic,Static")
$line = $method.Invoke($null, @())
Write-Host "You typed: $line"

This retrieves input exactly like the REPL (Read-Eval-Print Loop) would, helping mimic user interaction for specific automation needs.

Conclusion

PSConsoleHostReadLine is not something you’ll use in daily scripting, but it represents the power and flexibility of the PowerShell console infrastructure. Next time you’re customizing your terminal or debugging strange input behavior, you’ll know where to look!

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