Switch parameters and powershell.exe -File parameter

Question

According Microsoft:

In rare cases, you might need to provide a Boolean value for a switch parameter. To provide a Boolean value for a switch parameter in the value of the File parameter, enclose the parameter name and value in curly braces, such as the following: -File .\Get-Script.ps1 {-All:$False}

I have a simple script:

[CmdletBinding()] 
Param
(
    [switch] $testSwitch
)
$testSwitch.ToBool()

Next I am trying to run it this way:

powershell -file .\1.ps1 {-testSwitch:$false}

As result I receive an error: enter image description here

But if believe Microsoft it should work.

If I delete [CmdletBinding] attribute this error will not occur, but for some reasons $testSwitch.ToBool() returns False despite whether I pass $True or $False.

Why? What are the reasons of this behaviour?

This works for plain booleans, too.

Slogmeister Extraordinaire
– Slogmeister Extraordinaire

2018-09-07 18:14:06 +00:00
Commented Sep 7, 2018 at 18:14 — Slogmeister Extraordinaire
– Slogmeister Extraordinaire, Commented Sep 7, 2018 at 18:14

Johan de Haan · Accepted Answer · 2015-05-29 12:41:22Z

8

The workaround is to not use the -File parameter:

c:\scripts>powershell.exe .\test.ps1 -testswitch:$true
True
c:\scripts>powershell.exe .\test.ps1 -testswitch:$false
False

enter image description here

It is also an active bug on Microsoft Connect

edited May 29, 2015 at 12:41

answered May 29, 2015 at 9:01

Johan de Haan

1,0289 silver badges13 bronze badges

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

1 Comment

Pere Over a year ago

There is a difference between calling powershell from a powershell shell or from a cmd shell, and according to the screen capture and to the quoted text in the question the OP is calling it from a powershell, so this renders you answer almost unuseful.

Ansgar Wiechers · Accepted Answer · 2015-05-29 10:58:49Z

2

There are ways to make this work, for instance expanding the string:

[CmdletBinding()]
Param(
  [Parameter()]$testSwitch
)

$ExecutionContext.InvokeCommand.ExpandString($testSwitch)

However, you don't really need to do that. Simply run the script with or without the switch and check for the presence of the switch parameter:

[CmdletBinding()]
Param(
  [switch][bool]$testSwitch
)

$testSwitch.IsPresent

Demonstration:

C:\>powershell -File .\test.ps1 -testSwitch
True

C:\>powershell -File .\test.ps1
False

edited May 29, 2015 at 10:58

answered May 29, 2015 at 9:07

Ansgar Wiechers

202k27 gold badges286 silver badges363 bronze badges

3 Comments

olegk Over a year ago

I really need to specify $true or $false. There are a resons for this.

olegk Over a year ago

What this command actually do - $ExecutionContext.InvokeCommand.ExpandString($testSwitch)?

Ansgar Wiechers Over a year ago

@olegk Basically, it expands (PowerShell) expressions and variables in a string.

Collectives™ on Stack Overflow

Switch parameters and powershell.exe -File parameter

2 Answers 2

1 Comment

3 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

3 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related