How do I get the path of a directory where a file SQL backup is missing? - powershell

Question

The task is to track the execution of SQL backups. One of the tracking mechanisms is to browse the directory where the backups are saved and if the file is missing, you can send an email with the full address of the directory where the file is missing. This is what I am trying to implement with Powershell script, but for some reason my script doesn't work and doesn't give me the information I need.
$list = Get-ChildItem -Path network_path_to_share -Recurse -File | Where-Object {$_.DirectoryName -like '*FULL*' -and $_.LastWriteTime -ge (Get-Date).AddDays(-6)}
$fileExists = Test-Path $list
If ($fileExists)
{
#Do Nothing
}
Else
{
$list | Select DirectoryName
}
Can anyone help?

Answer 1

I suppose what you need is to test each file or path individually. You take Get-ChildItem with recurse, so it returns multiple files and stores them in $list.
If you do something like
Foreach ($item in $list) {
$fileexists = Test-Path $item
If ($fileexists -eq $false) {
do something }
}
You should be good to go. This would cycle through all items and does whatever you need to be done. If you compare against $false, you wouldn't need the else statement, and you could also just put "Test-Path" into the if-statement like
If (Test-Path $item -eq $false) {}
Edit: Sorry I accidentally posted the answer before finishing it lol
Also, as stackprotector correctly points out, Get-ChildItem can only retrieve items that exist, because how should it detect missing files.

Answer 2

If you're wanting to check for something that is missing or doesn't exist, you need to start with a known condition, e.g.: either the server names or expected file or directory names.
If you know that, then you can create a static list (or dynamically query a list from Active Directory for your SQL servers or something (assuming the backup file names correspond to the server names)) and then check the files that were created and output the missing ones for triage.
Here is a modification to your script (essentially the opposite of what you did) that might point you in the right direction:
## List of expected files
$ExpectedFiles = #(
'File1.bak',
'File2.bak',
'File3.bak',
'File4.bak'
'...'
)
## Get a list of created files
$list = Get-ChildItem -Path network_path_to_share -Recurse -File | Where-Object {$_.DirectoryName -like '*FULL*' -and $_.LastWriteTime -ge (Get-Date).AddDays(-6)} | Select -ExpandProperty Name
## Check whether each expected file exists in the array of backups that actually were created
foreach ($file in $ExpectedFiles) {
if (-not(Test-Path $list)) {
"$($file) is missing!"
}
}