Powershell Cmdlet

Cmdlet (pronounced like "command-let") is the basic command unit in PowerShell, small commands implemented by Microsoft based on the .NET framework.

Cmdlets differ from external programs in traditional shells, such as .exe or .bat files, in that they are built into the PowerShell runtime environment.

Each Cmdlet performs a specific task, such as retrieving data, setting properties, creating objects, exporting files, etc.

Cmdlet Naming Convention: Verb-Noun

All Cmdlets in PowerShell follow a unified "verb-noun" format, for example:

Get-Process: Retrieves process information
Set-Date: Sets the system date
New-Item: Creates a new item (such as a file or folder)
Remove-Service: Removes a service

This naming convention is intuitive and consistent, making it easy to remember and find.

Basic Cmdlet Syntax Structure

The syntax structure of a Cmdlet is generally as follows:

Verb-Noun

Example:

Get-Service -Name W32Time

Explanation:

Get-Service: Retrieves service objects
-Name W32Time: Specifies the service name to query as W32Time

Another example:

Stop-Process -Id 1234 -Force

-Id is a parameter that takes a value
-Force is a switch parameter, which does not require a value to be specified

Combining Parameters with Pipelines

Cmdlets support positional parameters, named parameters, and pipeline input. This allows commands to be flexibly combined to build complex workflows.

Example 1: Specifying parameter form

Get-Process -Name notepad

Example 2: Passing through pipeline

"notepad" | Get-Process -Name

Example 3: Object pipeline passed to another Cmdlet

Get-Process notepad | Stop-Process

In the above example, Get-Process retrieves the notepad process object, then passes it through the pipeline to Stop-Process to terminate it.

Viewing Cmdlet Help Information

PowerShell provides a complete help system. You can use Get-Help to view the usage of any Cmdlet:

Get-Help Get-Process

To view more parameter descriptions and examples, add -Detailed or -Examples:

Get-Help Get-Process -Examples

If you are using PowerShell for the first time, it is recommended to execute the following command once to update the local help:

Update-Help

Common Basic Cmdlet Quick Reference Table

Cmdlet	Description
`Get-Command`	View all available commands
`Get-Help`	View help information for commands
`Get-Process`	Get process list
`Get-Service`	Get service list
`Start-Service`	Start a service
`Stop-Service`	Stop a service
`Set-ExecutionPolicy`	Set execution policy
`New-Item`	Create new file or folder
`Remove-Item`	Delete file or folder
`Copy-Item`	Copy file or folder
`Move-Item`	Move file or folder
`Clear-Host`	Clear screen, similar to `cls`

Practical Example: File Operations

Create a folder:

New-Item -Path "C:\TestFolder" -ItemType Directory

Create a text file in that directory:

New-Item -Path "C:\TestFolder\demo.txt" -ItemType File

Write content to the file:

Set-Content -Path "C:\TestFolder\demo.txt" -Value "Hello PowerShell"

Read file content:

Get-Content -Path "C:\TestFolder\demo.txt"

Summary and Learning Recommendations

Cmdlet is the core unit of PowerShell, with each Cmdlet being a task executor with clear functionality.
The unified "verb-noun" naming convention makes Cmdlets predictable and easy to learn.
The combination of pipelines, parameter systems, and object models makes Cmdlets excellent for data processing and automation.
Mastering common Cmdlets and combining them with object operations is an important starting point for learning PowerShell.

Beginners are recommended to practice from the following aspects:

Use Get-Command to explore all available commands
Use Get-Help to learn how to look up command usage
Use commands like New-Item and Get-Content for local file operations
Try combining commands through pipelines to process data

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