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about_Alias_Provider

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Provider name

Alias

Drives

Alias:

Capabilities

ShouldProcess

Short description

Provides access to the PowerShell aliases and the values that they represent.

Detailed description

The PowerShell Alias provider lets you get, add, change, clear, and delete aliases in PowerShell.

An alias is an alternate name for a cmdlet, function, executable file, including scripts. PowerShell includes a set of built-in aliases. You can add your own aliases to the current session and to your PowerShell profile.

The Alias drive is a flat namespace that contains only the alias objects. The aliases have no child items.

The Alias provider supports the following cmdlets, which are covered in this article.

PowerShell includes a set of cmdlets that are designed to view and to change aliases. When you use Alias cmdlets, you do not need to specify the Alias: drive in the name. This article does not cover working with Alias cmdlets.

Types exposed by this provider

Each alias is an instance of the System.Management.Automation.AliasInfo class.

The Alias provider exposes its data store in the Alias: drive. To work with aliases, you can change your location to the Alias: drive by using the following command:

Set-Location Alias:

To return to a file system drive, type the drive name. For example, type:

Set-Location C:

You can also work with the Alias provider from any other PowerShell drive. To reference an alias from another location, use the Alias: drive name in the path.

Note

PowerShell uses aliases to allow you a familiar way to work with provider paths. Commands such as dir and ls are now aliases for Get-ChildItem, cd is an alias for Set-Location. and pwd is an alias for Get-Location.

Displaying the Contents of the Alias: drive

This command gets the list of all the aliases when the current location is the Alias: drive. It uses a wildcard character * to indicate all the contents of the current location.

PS Alias:\> Get-Item -Path *

In the Alias: drive, a dot ., which represents the current location, and a wildcard character *, which represents all items in the current location, have the same effect. For example, Get-Item -Path . or Get-Item \* produce the same result.

The Alias provider has no containers, so the above command has the same effect when used with Get-ChildItem.

Get-ChildItem -Path Alias:

Get a selected alias

This command gets the ls alias. Because it includes the path, you can use it in any PowerShell drive.

Get-Item -Path Alias:ls

If you are in the Alias: drive, you can omit the drive name from the path.

You can also retrieve the definition for an alias by prefixing the provider path with the dollar sign ($).

$Alias:ls

Get all aliases for a specific cmdlet

This command gets a list of the aliases that are associated with the Get-ChildItem cmdlet. It uses the Definition property, which stores the cmdlet name.

Get-Item -Path Alias:* | Where-Object {$_.Definition -eq "Get-ChildItem"}

Creating aliases

Create an alias from the Alias: drive

This command creates the serv alias for the Get-Service cmdlet. Because the current location is in the Alias: drive, the -Path parameter is not needed.

This command also uses the -Options dynamic parameter to set the AllScope option on the alias. The -Options parameter is available in the New-Item cmdlet only when you are in the Alias: drive. The dot (.) indicates the current directory, which is the alias drive.

PS Alias:\> New-Item -Path . -Name serv -Value Get-Service -Options "AllScope"

Create an alias with an absolute path

You can create an alias for any item that invokes a command. This command creates the np alias for Notepad.exe.

New-Item -Path Alias:np -Value c:\windows\notepad.exe

Create an alias to a new function

You can create an alias for any function. You can use this feature to create an alias that includes both a cmdlet and its parameters.

The first command creates the CD32 function, which changes the current directory to the System32 directory. The second command creates the go alias for the CD32 function.

When the command is complete, you can use either CD32 or go to invoke the function.

function CD32 {Set-Location -Path c:\windows\system32}
Set-Item -Path Alias:go -Value CD32

Changing aliases

Change the options of an alias

You can use the Set-Item cmdlet with the -Options dynamic parameter to change the value of the -Options property of an alias.

This command sets the AllScope and ReadOnly options for the dir alias. The command uses the -Options dynamic parameter of the Set-Item cmdlet. The -Options parameter is available in Set-Item when you use it with the Alias or Function provider.

Set-Item -Path Alias:dir -Options "AllScope,ReadOnly"

Change an aliases referenced command

This command uses the Set-Item cmdlet to change the gp alias so that it represents the Get-Process cmdlet instead of the Get-ItemProperty cmdlet. The -Force parameter is required because the value of the Options property of the gp alias is set to ReadOnly. Because the command is submitted from within the Alias: drive, the drive is not specified in the path.

Set-Item -Path gp -Value Get-Process -Force

The change affects the four properties that define the association between the alias and the command. To view the effect of the change, type the following command:

Get-Item -Path gp | Format-List -Property *

Rename an alias

This command uses the Rename-Item cmdlet to change the popd alias to pop.

Rename-Item -Path Alias:popd -NewName pop

Copying an alias

This command copies the pushd alias so that a new push alias is created for the Push-Location cmdlet.

When the new alias is created, its Description property has a null value. And, its Option property has a value of None. If the command is issued from within the Alias: drive, you can omit the drive name from the value of the -Path parameter.

Copy-Item -Path Alias:pushd -Destination Alias:push

Deleting an alias

This command deletes the serv alias from the current session. You can use this command in any PowerShell drive.

Remove-Item -Path Alias:serv

This command deletes aliases that begin with "s". It does not delete read-only aliases.

Clear-Item -Path Alias:s*

Delete read-only aliases

This command deletes all aliases from the current session, except those with a value of Constant for their Options property. The -Force parameter allows the command to delete aliases whose Options property has a value of ReadOnly.

Remove-Item Alias:* -Force

Dynamic parameters

Dynamic parameters are cmdlet parameters that are added by a PowerShell provider and are available only when the cmdlet is being used in the provider-enabled drive.

Options [System.Management.Automation.ScopedItemOptions]

Determines the value of the Options property of an alias.

  • None: No options. This value is the default.
  • Constant:The alias cannot be deleted and its properties cannot be changed. Constant is available only when you create an alias. You cannot change the option of an existing alias to Constant.
  • Private:The alias is visible only in the current scope, not in the child scopes.
  • ReadOnly:The properties of the alias cannot be changed except by using the -Force parameter. You can use Remove-Item to delete the alias.
  • AllScope:The alias is copied to any new scopes that are created.

Cmdlets supported

Using the pipeline

Provider cmdlets accept pipeline input. You can use the pipeline to simplify task by sending provider data from one cmdlet to another provider cmdlet. To read more about how to use the pipeline with provider cmdlets, see the cmdlet references provided throughout this article.

Getting help

Beginning in Windows PowerShell 3.0, you can get customized help topics for provider cmdlets that explain how those cmdlets behave in a file system drive.

To get the help topics that are customized for the file system drive, run a Get-Help command in a file system drive or use the -Path parameter of Get-Help to specify a file system drive.

Get-Help Get-ChildItem

Get-Help Get-ChildItem -Path alias:

See also