Environment Variables

Environment variables store information related to the current environment like the Operating System and user sessions. These global variables are name-value pairs that can be accessed across commands and programs.

Listing Environment Variables

Running the Get-ChildItem cmdlet on the Env: drive lists all the environment variables defined in the current environment.

PS > Get-ChildItem Env:

Name                           Value
----                           -----
ALLUSERSPROFILE                C:\ProgramData
APPDATA                        C:\Users\Prince\AppData\Roaming
COMPUTERNAME                   DESKTOP
ComSpec                        C:\Windows\system32\cmd.exe
HOMEDRIVE                      C:
NUMBER_OF_PROCESSORS           24
OS                             Windows_NT
PATH                           C:\Program Files\Common Files\Oracle\Java\javapath;C:\Program ...
...

A particular environment variable can also be specified by appending its name to the Env: drive:

PS > Get-Childitem Env:HOMEDRIVE

Name                           Value
----                           -----
HOMEDRIVE                      C:

Printing Environment Variables Values

An environment variable’s value can directly be printed by accessing the Value property:

PS > (Get-Childitem Env:HOMEDRIVE).Value
C:

Alternatively, a shorthand syntax can be used:

PS > $Env:HOMEDRIVE
C:

Creating Environment Variables

The syntax for creating environment variables is:

$Env:EXAMPLE_ENV_VAR = "custom value"

Note: Per convention, environment variable names are capitalized.