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about_Environment_Provider

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Provider name

Environment

Drives

Env:

Capabilities

ShouldProcess

Short description

Provides access to the Windows environment variables.

Detailed description

The PowerShell Environment provider lets you get, add, change, clear, and delete environment variables and values in PowerShell.

Environment variables are dynamically named variables that describe the environment in which your programs run. Windows and PowerShell use environment variables to store persistent information that affect system and process execution. Unlike PowerShell variables, environment variables are not subject to scope constraints.

The Environment drive is a flat namespace containing the environment variables specific to the current user's session. The environment variables have no child items.

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

Types exposed by this provider

Each environment variable is an instance of the System.Collections.DictionaryEntry class. The name of the variable is the dictionary key. The value of the environment variable is the dictionary value.

The Environment provider exposes its data store in the Env: drive. To work with environment variables, change your location to the Env: drive (Set-Location Env:), or work from another PowerShell drive. To reference an environment variable from another location, use the Env: drive name in the path.

Set-Location Env:

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

Set-Location C:

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

The Environment provider also exposes environment variables using a variable prefix of $env:. The following command views the contents of the ProgramFiles environment variable. The $env: variable prefix can be used from any PowerShell drive.

PS C:\> $env:ProgramFiles
C:\Program Files

You can also change the value of an environment variable using the $env: variable prefix. Any changes made only pertain to the current PowerShell session for as long as it is active.

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.

Getting environment variables

This command lists all the environment variables in the current session.

Get-Item -Path Env:

You can use this command from any PowerShell drive.

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

Get-ChildItem -Path Env:

Get a selected environment variable

This command gets the WINDIR environment Variable.

Get-ChildItem -Path Env:windir

You can also use the variable prefix format as well.

$env:windir

Create an environment variable

This command creates the USERMODE environment variable with a value of "Non-Admin". The -Path parameter value creates the new item in the Env: drive. The new environment variable is only usable in the current PowerShell session for as long as it is active.

PS C:\> New-Item -Path Env: -Name USERMODE -Value Non-Admin

Changing an environment variable

Rename an environment variable

This command uses the Rename-Item cmdlet to change the name of the USERMODE environment variable that you created to USERROLE. Do not change the name of an environment variable that the system uses. Although these changes affect only the current session, they might cause the system or a program to operate incorrectly.

Rename-Item -Path Env:USERMODE -NewName USERROLE

Change an environment variable

This command uses the Set-Item cmdlet to change the value of the USERROLE environment variable to "Administrator".

Set-Item -Path Env:USERROLE -Value Administrator

Copy an environment variable

This command copies the value of the USERROLE environment variable to the USERROLE2 environment Variable.

Copy-Item -Path Env:USERROLE -Destination Env:USERROLE2

Remove an environment variable

This command deletes the USERROLE2 environment variable from the current session.

Remove-Item -Path Env:USERROLE2

Remove an environment variable with Clear-Item

This command deletes the USERROLE environment variable by clearing its value.

Clear-Item -Path Env:USERROLE

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 env:

See also