What is the setlocal / endlocal equivalent for PowerShell?

Question

Objective

Isolate environmental variable changes to a code block.

Background

If I want to create a batch scrip

Answer 1

There is a way to achieve this in PowerShell:

Local Scope:

& { [System.Environment]::SetEnvironmentVariable('TEST', 'WORK Local', [System.EnvironmentVariableTarget]::Process)
[System.Environment]::GetEnvironmentVariable("TEST", [System.EnvironmentVariableTarget]::Process) }

This creates the environmental variable in the scope of the process same as above. Any call to it outside the scope will return nothing.

For a global one you just change the target to Machine:

& { [System.Environment]::SetEnvironmentVariable('TEST', 'WORK Global', [System.EnvironmentVariableTarget]::Machine) }

Any call to this outside the scope will return 'Work Global'

Putting it all together:

## create local variable and print
& { [System.Environment]::SetEnvironmentVariable('TEST', 'WORK Local', [System.EnvironmentVariableTarget]::Process)
[System.Environment]::GetEnvironmentVariable("TEST", [System.EnvironmentVariableTarget]::Process) }


function tt {
  ($env:TEST)
}

& { $TEST="EN"; $env:TEST="EN"; tt }
& { $TEST="change1"; $env:TEST="change1"; tt }
& { $TEST="change1"; $env:TEST="change2"; tt }

[System.Environment]::GetEnvironmentVariable("TEST", [System.EnvironmentVariableTarget]::Process)

& { [System.Environment]::SetEnvironmentVariable('TEST', 'WORK Global', [System.EnvironmentVariableTarget]::Machine) } ## create global variable

## Create local variable and print ( overrides global )
& { [System.Environment]::SetEnvironmentVariable('TEST', 'WORK Local', [System.EnvironmentVariableTarget]::Process)
[System.Environment]::GetEnvironmentVariable("TEST", [System.EnvironmentVariableTarget]::Process) }

[System.Environment]::GetEnvironmentVariable("TEST", [System.EnvironmentVariableTarget]::Machine) ## get global variable

[System.Environment]::SetEnvironmentVariable("TEST",$null,"USer") ## remove global variable

This gives us the following output:

WORK Local
EN
change1
change2
change2
WORK Local
WORK Global