How to use Get-ChildItem with excluding a list of items with an array in Powershell?

Question

I want to use an array for the exclusion:

Remove-Item -Path "$InstallDir\Lang\*" -Exclude "de.txt", "en.txt"

or

Get-ChildItem "$InstallDir\Lang"  -EXCLUDE "es.txt", "de.txt"| Remove-Item

These both work fine.

Whereas

Get-ChildItem "$InstallDir\Lang\*" -Exclude "$Language" | remove-item

does not work.

I tried several ways ( e.g. How to use Get-ChildItem with filter array in Powershell? or How to exclude list of items from Get-ChildItem result in powershell?) but I can´t find a solution. It seems as if $Language can't be interpreted by the command.

This is how $language is built:

[string]$Language = @('"de.txt"')
If ($PackageConfigFile.Language -notlike $Null) {
    foreach ($LIP in $PackageConfigFile.Language) {
        $Language += ",`n ""$LIP.txt"""
    }
}

$language has e.g. the following content

"de.txt",

"en.txt",

"es.txt"

Has anybody an idea?

Answer 1

$Language = @('de.txt')
If ($PackageConfigFile.Language -notlike $Null) {
    foreach ($LIP in $PackageConfigFile.Language) {
        $Language += "$LIP.txt" 
    } 
}

Answer 2

First:

Construct your $Language argument as an actual PowerShell array; what you attempted creates a multil-line string instead.

Creating that array should be as simple as:

$Language = $PackageConfigFile.Language -replace '$', '.txt'

-replace, with a collection (array) as the LHS, operates on each item in the collection individually; '$', '.txt' effectively appends .txt to the end ($) of each input item, and the resulting modified elements are collected in $Language as an array, of .NET type System.Object[].

Second:

Do not enclose $Language, your array argument, in "...".

Get-ChildItem $InstallDir\Lang\* -Exclude $Language | Remove-Item -WhatIf

---

If you enclose an array variable in "...", PowerShell converts it to a single string, composed of the array elements concatenated with the value of preference variable $OFS, which defaults to a space; e.g.:

PS> $arr = 'a', 'b', 'c'; "[$arr]"
[a b c]

---

For readers coming from a UNIX / bash background:

PowerShell variables do NOT need to be double-quoted when they're passed to other commands, whatever they may contain (spaces or other shell metacharacters).

When calling PowerShell-native functionality (cmdlets, functions, scripts), the variable's original type is preserved as-is (the ability to use the .NET Framework's rich type system is the core feature that exemplifies PowerShell's evolutionary quantum leap in the world of shells).

Only use "..." if you explicitly want to pass a string to the target command.