Powershell 'where' statement -notcontains - regex

Question

I have a simple excerpt form a larger script, basically I'm trying to do a recursive file search, including sub-directories (and any child of the exclude).
clear
$Exclude = "T:\temp\Archive\cst"
$list = Get-ChildItem -Path T:\temp\Archive -Recurse -Directory
$list | where {$_.fullname -notlike $Exclude} | ForEach-Object {
Write-Host "--------------------------------------"
$_.fullname
Write-Host "--------------------------------------"
$files = Get-ChildItem -Path $_.fullname -File
$files.count
}
At the moment this script will exclude the T:\temp\Archive\cst directory, but not the T:\temp\Archive\cst\artwork directory. I'm struggling to overcome this simple thing.
I've tried the -notlike (which I didn't really expect to work) but also the -notcontains which I was hopeful of.
Can anyone offer any advice, I'm thinking it would require a regex match which I'm reading up on now, but not very familiar with.
In the future the $exclude variable will be an array of strings (directories) but at the moment just trying to get it to work with a straight string.

Answer 1

Try:
where {$_.fullname -notlike "$Exclude*"}
You could also try
where {$_.fullname -notmatch [regex]::Escape($Exclude) }
but the notlike apporach is easier.

Answer 2

When used without wildcards the -like operator does the same as the -eq operator. If you want to exclude a folder T:\temp\Archive\cst and everything below it, you need something like this:
$Exclude = 'T:\temp\Archive\cst'
Get-ChildItem -Path T:\temp\Archive -Recurse -Directory | ? {
$_.FullName -ne $Exclude -and
$_.FullName -notlike "$Exclude\*"
} | ...
-notlike "$Exclude\*" would only exclude subfolders of $Exclude, not the folder itself, and -notlike "$Exclude*" would also exclude folders like T:\temp\Archive\cstring, which may be undesired.
The -contains operator is used to check if a list of values contains a particular value. It doesn't check if a string contains a particular substring.
See Get-Help about_Comparison_Operators for further information.

Answer 3

Try changing
$Exclude = "T:\temp\Archive\cst"
To:
$Exclude = "T:\temp\Archive\cst\*"
This will still return the folder CST as it is a child item of Archive, but will exclude anything under cst.
Or:
$Exclude = "T:\temp\Archive\cst*
But that will also exclude anyfiles that start with "cst" under Archive. Same goes for Graimer's answer, jsut be aware of the trailing \ and if it's important to what you are doing

Answer 4

For those looking for a similar answer, what I ended up going with (to parse an array paths for a wildcard match):
# Declare variables
[string]$rootdir = "T:\temp\Archive"
[String[]]$Exclude = "T:\temp\Archive\cst", "T:\temp\archive\as"
[int]$days = 90
# Create Directory list minus excluded directories and their children
$list = Get-ChildItem -Path $rootdir -Recurse -Directory | where {$path = $_.fullname; -not #($exclude | ? {$path -like $_ -or $path -like "$_\*" }) }
Provides what I needed.

Answer 5

Thought I would add to this as I recently had a similar problem answered. You can use the -notcontains condition, but the thing that is counter intuitive is that the $exclude array needs to be at the start of the expression.
Here is an example.
If I perform the following no items are excluded and it returns "a","b","c","d"
$result = #()
$ItemArray = #("a","b","c","d")
$exclusionArray = #("b","c")
$ItemArray | Where-Object { $_ -notcontains $exclusionArray }
If I switch the variables around in the expression then it works and returns "a","d".
$result = #()
$ItemArray = #("a","b","c","d")
$exclusionArray = #("b","c")
$ItemArray | Where-Object { $exclusionArray -notcontains $_ }
I am not sure why the arrays have to be this way around to work. If anyone else can explain that would be great.
EDITED 12/12/20 - I now know that the other operation to use is "-in" as in
$_ -notin $exclusionArray