Excluding folders using Get-ChildItem -Exclude - powershell

Question

I require to exclude user profiles from \\Computer\c$\Users folder when using Get-ChildItem.
I potentially need to exclude 100 profiles from various machines so have created a variable that contains all user profiles from an AD security group that I want excluding but when I run the below command it doesn't work but if I list the profiles in plain text it does work.
Get-ChildItem "\\$computer\c$\Users" -Exclude $ListOfUsers
But works if I run Get-ChildItem "\\$computer\c$\Users" -Exclude Bob1,Bob2,Bob3,Bob4,Bob5
My code to obtain the users from AD security groups are below and the format it outputs to is like the above with commas.
## collects users from groups and adds to exlusion list.
$1stline = Get-ADGroupMember GG_1st_Line_Team | Select SamAccountName
$2ndline = Get-ADGroupMember GG_2nd_Line_Team | Select SamAccountName
$3rdline = Get-ADGroupMember GG_3rd_Line_Team | Select SamAccountName
$FieldTech = Get-ADGroupMember "Field tech" | select SamAccountname
$Excluded = $1stline + $2ndline + $3rdline + $Fieldtech | Out-File "C:\temp\Members.txt"
(get-content c:\temp\Members.txt) -join "," | out-file C:\temp\Format.txt
$format = get-content c:\temp\format.txt; $format = $format -replace '\s',''; $format = $format -replace ',SamAccountName,--------------,',''; $format = $format.trimend(",,") | Out-File "C:\temp\newFormat.txt"
$excluded = Get-Content C:\Temp\newFormat.txt
This will create a text file with 100 names with no spaces, only commas to seperate the users. If I Write-Host the variable $newformat the commas are White along with the text but if I put the Profile names in plain text then the commas are grey...

Answer 1

The excessive use of Out-File is unnecessary and will cause you issues as it changes objects into strings. You then have to use commands like Split and Join to turn the strings back into the object (arrays here) you require.
Out-File should only be used when you actually need the output as a file.
With a few simple changes to your script it'll do what you want, and be a lot simpler too!
You can use ExpandProperty to only return the value of SamAccountName itself as a string rather than an object.
You can then simply create an array of those strings and use this to exclude those accounts/folders from Get-ChildItem,
$1stline = Get-ADGroupMember GG_1st_Line_Team | Select-Object -ExpandProperty SamAccountName
$2ndline = Get-ADGroupMember GG_2nd_Line_Team | Select-Object -ExpandProperty SamAccountName
$3rdline = Get-ADGroupMember GG_3rd_Line_Team | Select-Object -ExpandProperty SamAccountName
$FieldTech = Get-ADGroupMember "Field tech" | Select-Object -ExpandProperty SamAccountname
$excluded = $1stline,$2ndline,$3rdline,$Fieldtech
Get-ChildItem "\\$computer\c$\Users" -Exclude $excluded
You could then look into using a foreach loop with Get-ADGroupMember to cut down on the duplicated Get-ADGroupMember code.

Answer 2

The problem here seems to be that you're using a [string] variable with a value of Tom,Dick,Harry.
I bet you've got no folders like this, have you?
Whilst you can pass a [string] in to the -Exclude parameter; that will be a singleton (a single, scalar value); and the best you'll get is a single exclusion.
What you really want to pass in is a string array: [string[]]!
[string]$excludedString = "Tom,Dick,Harry"
[string[]]$excludedArray = $excludedString -split ","
Get-ChildItem -Path "C:\users" -Exclude $excludedArray