PowerShell Objects

Unlike traditional text-based shells (like Bash), PowerShell is fundamentally object-oriented. Every command returns an object or a collection of objects, which can be manipulated via their properties and methods.

The Object Pipeline

In a text shell, the pipeline passes strings. In PowerShell, the pipeline passes structured data.

• Text Approach: ls -l | grep ".txt" (Requires parsing text columns).
• PowerShell Approach: Get-ChildItem | Where-Object Extension -eq ".txt" (Filters by the Extension property).

Discovery: Get-Member

The Get-Member cmdlet (alias gm) is the primary tool for inspecting objects. It reveals the object's TypeName (.NET class), Properties (data), and Methods (actions).

# Example: Inspecting a process
Get-Process | Get-Member

Creating Custom Data: PSCustomObject

The PSCustomObject is a lightweight container for structured data. It is the standard way to pass custom information through the pipeline.

$server = [PSCustomObject]@{
    Name = "WebSrv01"
    IP   = "192.168.1.10"
    Role = "Web"
}

Core Principles

1. Filter Left: Filter as early as possible in the pipeline to improve performance.
2. Output Objects, Not Text: Functions should return objects so they can be reused by other cmdlets.
3. Everything is .NET: PowerShell is built on .NET, meaning you have access to the entire .NET library directly from the shell.

See Also

• wiki-as-codebase