Run Powershell script from inside other Powershell script with dynamic redirection to file

Question

I have been struggling with this problem and researching around but can't get a solution

My problem: I need to run a Powershell script from inside another Powershell script and redirect the output stream to a file. So far so good. The real issue comes when I need to control the amount of logging through a variable (e.g. write only errors or only error + warning + success output streams).

I can get around it by hard-coding the command as in:

Powershell -File "\path\myscript.ps1" 2>&1> $logFilePathAndName

However, I want to give the user a couple of options for the redirect operator and want to avoid hardcoding each one of them. For that, I was thinking to just code something similar to :

$logStreams = "2>&1>"
Powershell -File "\path\myscript.ps1" $logStreams $logFilePathAndName

The last command does run my script (myscript.ps1 has no input params) but it does not write anything to the file at $logFilePathAndName.

I tried various syntax with Invoke-Command, Invoke-Expression, the call operator and Powershell -Command with no luck.

Looked at this post, had several tries but I can't just get it to work. For example this runs my script but does not write anything to the output log:

$logStreams = "2>&1>"
$command = '"C:\myscript.ps1" $_logStreams "C:\outputlog.txt"'
iex "& $command"

Is there a way to pass a variable string for the redirect operator OR run a string containing the entire command with a variable interpolated for the output redirector ?

Answer 1

Your last bit there is very close, but I'm not sure why you have the underscore in there, and you need to escape your dollar sign, and close the entire thing in double quotes to cause string extrapolation.

$logStreams = "2>&1>"
$command = "'C:\myscript.ps1' $logStreams 'C:\outputlog.txt'"
iex "& $command"

I just tested that locally and it works fine.