CODEWITHSUNDEEP
powershellescapingstart-process
Eric Furspan
Eric Furspan

Reputation: 761

Start-Process and the Stop Parsing (--%) parameter

I am having trouble getting the --% parameter to work as expected. My $TaskParams variable has the character '<' which is interpreted as a redirection by powershell, therefore needs to be escaped.

However the following does not work:

$CreateTask = Start-Process PowerShell.exe "$ScriptLocation --% $TaskParams" -Wait -PassThru

Without the --%, and when I manually remove any '<' characters, it works:

$CreateTask = Start-Process PowerShell.exe "$ScriptLocation $TaskParams" -Wait -PassThru

error received:

 Start-Process : A positional parameter cannot be found that accepts argument 
'--%'.

note: I am using PS 5.0

Am I using the --% parameter wrong? Any help or pointers is appreciated. Thanks

Upvotes: 1

Views: 1913

Answers (3)

Bill_Stewart
Bill_Stewart

Reputation: 24535

You do not need to spin up a new copy of powershell.exe or use Start-Process to run a script from within another script. Just put the script command and its parameters as a line from within the other script. For example, suppose you have script2.ps1:

param(
  [String] $Name
)
Write-Host "Hello, $Name"

Now suppose you also have script1.ps1:

Write-Host "This is script1.ps1"
.\Script2.ps1 -Name "Bill Stewart"
Write-Host "script1.ps1 is finished"

If you now run script1.ps1:

PS C:\> .\Script1.ps1
This is script1.ps1
Hello, Bill Stewart
script1.ps1 is finished

Upvotes: 3

TheMadTechnician
TheMadTechnician

Reputation: 36297

If you really want to use Start-Process you could encode the argument, and run it as such. I use something similar to this when elevating past UAC:

$Code = ". '$ScriptLocation' $TaskParams"
$Encoded = [Convert]::ToBase64String([Text.Encoding]::Unicode.GetBytes($code))

Start-Process PowerShell.exe -ArgumentList "-EncodedCommand",$Encoded -Wait -PassThru

I'm fairly certain that would accomplish what you're looking for.

Upvotes: 3

briantist
briantist

Reputation: 47792

The stop-parsing symbol --% only works when calling executables directly or with the call operator &; it's not for use when calling PowerShell scripts / functions / cmdlets.

Upvotes: 4

Related Questions