How can I check if printer is in some state longer than 30 minutes? - powershell

Question

I have a script, checking state of all printers from all print-servers through WMI. Result looks like this:
Name location Status
---- -------- ------
Xerox wc275.1 Offline
dnj-4000.1 Offline
6040.1 Offline
m225.02 Offline
5225.01 Offline
How can I check if printer is offline for 30 minutes? I can put an output in a text file for logging or smth? All I need is the "how it can be done". Later I will configure email notifications etc. But I don't know nothing about logging and parsing in powershell.

Answer 1

If you're outputting these results to a text file every half hour, you could use Compare-Object to report back on differences/similarities between 2 files:
$file1 = get-childitem -path "C:\Powershell\Test\Text" | sort LastWriteTime | select -ExpandProperty FullName -last 2 | Out-File C:\Powershell\path1.txt
$file2 = Get-Content -Path "C:\Powershell\path1.txt" | Select-Object -First 1
$file3 = Get-Content -Path "C:\Powershell\path1.txt" | Select-Object -Last 1
Compare-Object -ReferenceObject (Get-Content $file2) -DifferenceObject (Get-Content $file3) -IncludeEqual -ExcludeDifferent | sort InputObject
In this, List1.txt contains:
Xerox wc275.1 Offline
dnj-4000.1 Offline
6040.1 Offline
m225.02 Offline
5225.01 Offline
List2.txt contains:
Xerox wc275.1 Offline
dnj-4000.1 Online
6040.1 Offline
m225.02 Offline
5225.01 Online
So the result gives the lines that are the same as 30 minutes previously:
PS C:\WINDOWS\system32> C:\Powershell\Test\CompareMostRecentFiles.ps1
InputObject SideIndicator
----------- -------------
6040.1 Offline ==
m225.02 Offline ==
Xerox wc275.1 Offline ==
Notes:
This checks the 2 most recent files in a particular folder, so if you're running a printer check every 30 minutes and exporting to a text file, make sure the text files are being output to their own specific folder that do not contain anything else, otherwise you won't get correct results. You will also need to ensure your printer check script creates unique text files and doesn't keep overwriting the same one.

Answer 2

Done it using infinite loop.
$printers = #{}
Get-WmiObject -Class Win32_Printer |
ForEach-Object {
$printers[$_.Name] = $_ |
Select-Object Name,DetectedErrorState,#{Name='PreviousStatus';Expression={$_.DetectedErrorState}},#{Name='StatusTime';Expression={0}}
}
Do {
$check = Get-WMIObject -Class Win32_Printer
ForEach($printer in $check) {
If($printers[$printer.Name].DetectedErrorState -ne $printer.DetectedErrorState) {
$printers[$printer.Name].PreviousStatus = $printers[$printer.Name].DetectedErrorState
$printers[$printer.Name].DetectedErrorState = $printer.DetectedErrorState
$printers[$printer.Name].StatusTime = 0
} Else {
$printers[$printer.Name].StatusTime += 1
}
}
Start-Sleep 60
} While ($True)
Big thanks to mr.Cduff for this idea.