Iterate through folders and check if a certain file exists - file

Question

I was asked the following: Iterate through a list of folders, then iterate through a list of subfolders and finally check if there's a file named "can_erase.txt" on each subfolder. If the file exists, I must read it, save a parameter and delete the respective folder (not the main folder, but the subfolder which contains the file).
I started by using a for loop, but the names of the folders are random and I reached a dead end, so I thought I could use a foreach. Can anyone help me?
EDIT: My code is still pretty basic, since I know the names of the parent folders (they're named stream1, stream2, stream3 and stream4) but their subfolders are randomly named.
My current code:
For ($i=1; $i -le 4; $i++)
{
cd "stream$i"
Get-ChildItem -Recurse | ForEach (I don't know which parameters I should use)
{
#check if a certain file exists and read it
#delete folder if the file was present
}
cd ..
}

Answer 1

In this situation, you'll need multiple loops to get the stream folders, get those subfolders, then parse through all the files in the subfolders.
foreach ($folder in (Get-ChildItem -Path 'C:\streamscontainerfolder' -Directory)) {
foreach ($subFolder in (Get-ChildItem -Path $folder -Directory)) {
if ('filename' -in (Get-ChildItem -Path $subFolder -File).Name) {
Remove-Item -Path $subFolder -Recurse -Force
continue
}
}
}
The alternative to this is using the pipeline:
# This gets stream1, stream2, etc. added a filter to be safe in a situation where
# stream folders aren't the only folders in that directory
Get-ChildItem -Path C:\streamsContainerFolder -Directory -Filter stream* |
# This grabs subfolders from the previous command
Get-ChildItem -Directory |
# Finally we parse the subfolders for the file you're detecting
Where-Object { (Get-ChildItem -Path $_.FullName -File).Name -contains 'can_erase.txt' } |
ForEach-Object {
Get-Content -Path "$($_.FullName)\can_erase.txt" |
Stop-Process -Id { [int32]$_ } -Force # implicit foreach
Remove-Item -Path $_.FullName -Recurse -Force
}
As a default, I'd recommend using -WhatIf as a parameter to Remove-Item so you can see what it would do.
Bonus after more thinking:
$foldersToDelete = Get-ChildItem -Path C:\Streams -Directory | Get-ChildItem -Directory |
Where-Object { (Get-ChildItem -Path $_.FullName -File).Name -contains 'can_erase.txt' }
foreach ($folder in $foldersToDelete) {
# do what you need to do
}
Documentation:
Get-ChildItem
ForEach-Object
Where-Object
Remove-Item
about_Continue
about_ForEach
about_Comparison_Operators
System.IO.FileSystemInfo