CODEWITHSUNDEEP
powershell
Hobbes
Hobbes

Reputation: 2115

Powershell doesn't fill variable

I've got a Powershell script which is called with an argument that contains a file name. I want to strip the extension from the filename. This is the script:

param([string]$input_filename)
$inputFileNameOnly = [System.IO.Path]::GetFileNameWithoutExtension($input_filename) | Out-file "myfile.log" -Append
Write-Output "input filename without extension: " $inputFileNameOnly | Out-file "myfile.log" -Append

When I run the file: .\myscript.ps1 "E:\Projectdata\Test book.html"

I can see that the call [System.IO.Path]::GetFileNameWithoutExtension($input_filename) works: the first line in my log file is "Test book".

But nothing is placed after "input filename without extension: ". No value is assigned to variable $inputFileNameOnly.

What am I doing wrong here? There doesn't seem to be a type mismatch: [System.IO.Path]::GetFileNameWithoutExtension outputs a string.

I'm using Powershell 5 in Windows 10.

Upvotes: 0

Views: 231

Answers (1)

T-Me
T-Me

Reputation: 1884

You are a little to fast with your pipes:

$inputFileNameOnly = [System.IO.Path]::GetFileNameWithoutExtension($input_filename) | Out-file "myfile.log" -Append

Those are two steps in one: [System.IO.Path]::GetFileNameWithoutExtension($input_filename) | Out-file... will get your value and write it to a file. However this action will not provide any output that can be captured in $inputFileNameOnly. $inputFileNameOnly is $Null.

Instead save the filename first in a variable and use that for the Out-File:

$inputFileNameOnly = [System.IO.Path]::GetFileNameWithoutExtension($input_filename) 
Out-file -InputObject $inputFileNameOnly -FilePath "myfile.log" -Append

Some cmdlets that don't provide output to the piple have the parameter -PassThru to force them sending something into the pipeline. Unfortunately Out-File doesn't.

Upvotes: 1

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