Get-CPUUsage.ps1

# This script contains a function (Get-CPUUsage) that displays per-core CPU usage as a grid of blocks listing % value, 
 # with an associated color (green, yellow, red) at intervals of 500ms.

 
 Function Three-Chars ($Value){
    $N = 1..2

    If ([bool]($N -match ([string]$Value).Length)){
        
            $Y = ""
            (1..(3 - ([string]$Value).Length)).ForEach({$Y += " "})
            $Y += [string]$Value
        
            Return $Y
          
         } #Close If
         
    Else {Return $Value}

} #Close function

Function Get-CPUUsage {
    [CmdletBinding()] 
    param( 
        [Parameter(Mandatory=$False)][Alias('Poll')][int]$PollingIntervalMS,
        [Parameter(ParameterSetName='Logging')][string]$LogFile,
        [Parameter(ParameterSetName='Logging')][switch]$IncludeAverage,
        [Parameter(ParameterSetName='Logging')][switch]$UnixTime,
        [Parameter(Mandatory=$False)][switch]$Quiet
        
        )

begin {        

If ($null -eq $PollingIntervalMS -or $PollingIntervalMS.Length -eq 0){$PollingIntervalMS = 500}

If ($Quiet.IsPresent -and ($LogFile -eq $null -or $LogFile.Length -eq 0)){throw "PEBKAC error: It doesn't make sense to specify -Quiet and not specify an output logfile"}

If (!($Quiet.IsPresent)){

    If ($null -eq $Global:CPUParams){

        $Global:CPUParams = @{}
    
        $Global:CPUParams.Add("Cores",(Get-CimInstance Win32_ComputerSystem).NumberOfLogicalProcessors)
    
    #region 0. Identify preferred X/Y Grid mapping
    
        $SqRt = [system.math]::Sqrt($Global:CPUCores)
    
        If ($SqRt.GetType().Name -match "Int"){
        
                $Global:CPUParams.Add("X",$SqRt)
                $Global:CPUParams.Add("Y",$SqRt)
    
                } #Close if square root
        Else {
    
        $CoordTest = New-Object System.Collections.ArrayList
        $UpperLimit = ([system.math]::Ceiling([system.math]::Sqrt($Global:CPUParams.Cores))) * 2
    
        (2..$UpperLimit).ForEach({$CoordTest.Add([pscustomobject]@{"X"=$_; "Y"=($Global:CPUParams.Cores / $_); "Diff"=($null)}) | Out-Null})
        
        $CoordTest.ForEach({$_.Diff = [System.Math]::abs(($_.X - $_.Y))})
        $CoordTest = $CoordTest.Where({[string]($_.Diff) -notmatch '\.'}) | Sort-Object Diff
    
        $ChosenCoords = $CoordTest.Where({$_.Diff -eq ($CoordTest[0].Diff) -and ($_.X -ge $_.Y)})
    
        Try {$Global:CPUParams.Add("X",($ChosenCoords.X))}
        Catch {$Global:CPUParams.'X' = $ChosenCoords.X}
        
        Try {$Global:CPUParams.Add("Y",($ChosenCoords.Y))}
        Catch {$Global:CPUParams.'Y' = $ChosenCoords.Y}
    
        } #Close Else
    
    } #Close If $null eq $Global:CPUParams
    
    #endregion 0.
    
    #region 1. Build output template
    $ExecutionTemplate = New-Object System.Collections.ArrayList
    
    $BaseString = 'Write-Host "[CC]" -ForegroundColor FG -BackgroundColor BG -NoNewLine; '
    
    $CoreCounter = 0
    
    $CoreRowHash = @{}
    
    (0..($Global:CPUParams.Y - 1)).ForEach({
    
    $Row = $_
    
    $LineString = ""
    
        (0..($Global:CPUParams.X - 1)).ForEach({
    
        $Column = $_
    
        $ReplString = $BaseString -replace 'CC',"CC$($CoreCounter)" -replace 'FG',"FG$($CoreCounter)" -replace 'BG',"BG$($CoreCounter)"
    
        If ($Column -eq ($Global:CPUParams.X - 1)){$ReplString = $ReplString -replace '-NoNewLine',''}
    
        $LineString += $ReplString
    
        $CoreRowHash.Add($CoreCounter,$Row)
    
        $CoreCounter++
    
        }) #Close X
    
    $ExecutionTemplate.Add($LineString) | Out-Null
    
    }) #Close Y
    
    #endregion 1.
    
    #region 2. Build %/Color Hash Table
    $ColorHash = @{}
    
    (0..2).ForEach({$ColorHash.Add($_,[pscustomobject]@{"FG"="DarkCyan";"BG"="Cyan"})})
    (3..49).ForEach({$ColorHash.Add($_,[pscustomobject]@{"FG"="DarkGreen";"BG"="Green"})})
    (50..79).ForEach({$ColorHash.Add($_,[pscustomobject]@{"FG"="DarkYellow";"BG"="Yellow"})})
    (80..99).ForEach({$ColorHash.Add($_,[pscustomobject]@{"FG"="DarkRed";"BG"="Red"})})
    $ColorHash.Add(100,[pscustomobject]@{"FG"="White";"BG"="Red"})
    
    #endregion 2.

}

If ($LogFile.Length -gt 0){

    $LogOutput = $true

    try {$Cores = (Get-WmiObject -Query "SELECT Name, PercentProcessorTime FROM Win32_PerfFormattedData_PerfOS_Processor WHERE NOT Name LIKE '_Total'" -ErrorAction Stop)| Select-Object @{N="Name"; E={[int]($_.Name)}},PercentProcessorTime,@{N="PercentAsString";E={Three-Chars -Value ($_.PercentProcessorTime)}} | Sort-Object Name}
    catch {throw "Unable to execute Get-WmiObject"}

    $CSVHeader = '"Time",' + '"Core ' + ($Cores.Name -join '","Core ') + '"'   

    If ($IncludeAverage.IsPresent){$CSVHeader = $CSVHeader + ',"Average"'}

    Try {$CSVHeader | Out-File $LogFile -ErrorAction Stop}
    Catch {throw "Unable to write to logfile"}

} #Close if $LogFile.Length -gt 0

Else {$LogOutput = $false}

} #End Begin

process {
#region 3. Put it all together
Do {

    try {$Cores = (Get-WmiObject -Query "SELECT Name, PercentProcessorTime FROM Win32_PerfFormattedData_PerfOS_Processor WHERE NOT Name LIKE '_Total'" -ErrorAction Stop)| Select-Object @{N="Name"; E={[int]($_.Name)}},PercentProcessorTime,@{N="PercentAsString";E={Three-Chars -Value ($_.PercentProcessorTime)}} | Sort-Object Name}
    catch {throw "Unable to execute Get-WmiObject"}

    If ($LogOutput -eq $true){

        If ($UnixTime.IsPresent){$Time = [System.DateTimeOffset]::Now.ToUnixTimeMilliseconds()}
        Else {
        
            $Now = $Now = [System.DateTimeOffset]::Now
            $Time = $Now.Month.ToString() + '/' + $Now.Day.ToString() + '/' + $Now.Year.ToString() + ' ' + $Now.TimeOfDay.ToString()
        
        }
        
        $CSVLine = '"' + "$Time" + '","' + ($Cores.PercentProcessorTime -join '","') + '"'

        If ($IncludeAverage.IsPresent){$CSVLine = $CSVLine + ',"' + "$([int](($Cores.PercentProcessorTime | Measure-Object -Average).Average))" + '"'}
        
        $CSVLine | Out-File $LogFile -Append

         }

    If (!($Quiet.IsPresent)){

    $ExecutionStrings = New-Object System.Collections.ArrayList

    $ExecutionTemplate.ForEach({$ExecutionStrings.Add($_)})
    
    $Cores.ForEach({
     
     $C = $_
     [int]$CID = $C.Name
    
     $CoreLine = $CoreRowHash.($CID)
     $CoreColors = $ColorHash.[int]($C.PercentProcessorTime)
    
     $CoreUsedString = 'CC' + "$($CID)"
     $CoreFGString = 'FG' + "$($CID)"
     $CoreBGString = 'BG' + "$($CID)"
    
     $ExecutionStrings[$CoreLine] = $ExecutionStrings[$CoreLine] -replace "$CoreUsedString","$($C.PercentAsString)"
     $ExecutionStrings[$CoreLine] = $ExecutionStrings[$CoreLine] -replace "$CoreFGString","$($CoreColors.FG)"
     $ExecutionStrings[$CoreLine] = $ExecutionStrings[$CoreLine] -replace "$CoreBGString","$($CoreColors.BG)"
    
     }) #Close Cores.ForEach
    
    Clear-Host
    
    $ExecutionStrings.ForEach({Invoke-Expression $_})

} #Close If !$Quiet.IsPresent

    

Start-Sleep -Milliseconds $PollingIntervalMS

} #Close Do
Until ($null -eq $Cores)

#endregion 3.

} #close Process

end {}

} #Close Function