Return value of environment variable with powershell

Question

I have the name of an environment variable in a variable and I want to get the value. How do I do that? I've tried:

PS C:\Users\Joe> $v="USERDOMAIN"
PS C:\Users\Joe> "$env:$v"
At line:1 char:2
+ "$env:$v"
+  ~~~~~
Variable reference is not valid. ':' was not followed by a valid variable name character. Consider using ${} to
delimit the name.
    + CategoryInfo          : ParserError: (:) [], ParentContainsErrorRecordException
    + FullyQualifiedErrorId : InvalidVariableReferenceWithDrive

PS C:\Users\Joe> "$env:$($v)"
At line:1 char:2
+ "$env:$($v)"
+  ~~~~~
Variable reference is not valid. ':' was not followed by a valid variable name character. Consider using ${} to
delimit the name.
    + CategoryInfo          : ParserError: (:) [], ParentContainsErrorRecordException
    + FullyQualifiedErrorId : InvalidVariableReferenceWithDrive

Vladmir · Accepted Answer · 2014-08-13 11:34:44Z

12

Two lines

$v = "Path"
(get-item env:$v).Value

One line

iex ('$env:' + $x)

answered Aug 13, 2014 at 11:34

Vladmir

1,2659 silver badges13 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

Jason Shirk Over a year ago

iex is a bad idea, e.g. if you have $x = '$(del -re -force c:\; "Path")' (say from an attacker) - then you'll be unhappy you used Invoke-Expression.

Vladmir Over a year ago

I agree with you. But plenty of scenarios allow to do it when no user input allowed

Mark Allison Over a year ago

Thanks @JasonShirk do you have an alternative injection-proof solution?

Jason Shirk Over a year ago

The first example here is safe from injection.

Jason Shirk Over a year ago

@Vladmir - I know iex is safe for some scenarios, but people learn about it and misuse it so I try to steer people towards safer solutions and there usually are better/safer solutions.

|

mklement0 · Accepted Answer · 2018-03-21 02:49:34Z

1

To complement Vladimir's helpful answer with a solution that makes direct use of the .NET framework:

$v="USERDOMAIN"
[Environment]::GetEnvironmentVariable($v)

answered Mar 21, 2018 at 2:49

mklement0

452k68 gold badges727 silver badges986 bronze badges

Collectives™ on Stack Overflow

Return value of environment variable with powershell

2 Answers 2

6 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

6 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related