Writing a null value in red

Question

I have a basic command I'm using to check around 100 servers for the last 5 updates and return their installed date. I'd like to get the script to return the line in red if the installed date is blank.

The command is

 Get-WmiObject -Class Win32_QuickFixEngineering -ComputerName $ComputerName | Select-object -Property PSComputerName, @{n='HotFix ID';e={$_.hotfixid}}, @{n='Installation Date';e={$_.installedon}} | select -Last 05

I tried to use format-color but it wouldn't work. The output of the command looks like this

PSComputerName HotFix ID Installation Date
-------------- --------- -----------------
DC1            KB4132216 10/6/2021 12:00:00 AM

DC1            KB4535680 11/3/2021 12:00:00 AM

DC1            KB4589210

DC1            KB5005698 10/6/2021 12:00:00 AM

DC1            KB5007192 11/16/2021 12:00:00 AM

The line without a date I'd like to be red. Is this possible?

Thank you!

user_934946 · Answer

A couple of comments regarding your script

You are using Select -last 05 but the wmi command you ran won't gave you the items in an InstalledOn ascending order. The 5 items you get are the last 5, but not from a sorted perspective.
You can combine your 2 select statements for efficiency purposes (eg: Select -Last 5 -Property ...

Now, for your actual problem, I would go with an ANSI escape sequence. Using the escape character then specifying a virtual terminal sequence will allow you to modify the color of text and other text attributes such as bolding and underlining.

Here's a modified script that account for the previous comments and integrate an escape sequence to format your output as you want it.

$ComputerName = 'localhost'
$HotFixes = Get-WmiObject -Class Win32_QuickFixEngineering -ComputerName $ComputerName 


$ColoringCondition = { 
    Param($Value)
    $e = [char]27 # For PS 5.1 ... In PS 7.0+, this can be removed and occurences of $e below replaced by `e
    if ([String]::IsNullOrEmpty($_.'InstalledOn')) { 
        return "$e[5;31m$($Value)$e[0m"; 
    }
    return $Value 
}


$Last5 = $HotFixes | Sort-Object -Property installedon -Descending | 
Select -First 5 -Property @{'Name' = 'PSComputerName' ; 'Expression' = { . $ColoringCondition $_.PSComputerName  } }, 
@{n = 'HotFix ID'; e = {. $ColoringCondition $_.hotfixid } }, 
installedon

$Last5 # Print output

Output

Updates have been sorted by InstalledOn property (Descending so that the most recent is displayed first) and because of that sort, we select the 5 first item (5 most recent)
A coloring condition is checked against all the properties and if the installation date is missing, the coloring is added to the cell value of the line.

Note: If you are using Powershell 7+, you do not have to declare $e = [char]27 and you can simply use `e (backtick + e) instead.

Note 2:

As a byproduct of the initial sorting (sort by installation date, descending), this mean that all the updates with an empty installation date will go to the bottom and likely never get selected by the top 5. I'd think that if they have an empty installation date, they might be updates that came in with the system and can safely be ignored but that is something to keep in mind.

References:

Console Virtual Terminal Sequences - Text formatting

Using ANSI Escape Sequences in Powershell

Powershell - About special Characters (For PS 7.0+)

Writing a null value in red

1 Answers