Stepping up my Powershell Game

I watched a fascinating video about Powershell in the enterprise from a talk at TechEd given by Don Jones. It made me realize that it was time to step up my game a bit when it came to Powershell.

Two things I've decided to get more serious about are functions and version control. Version control doesn't look like it will be too hard to implement. We don't have any developers in-house so I don't have anything at-hand to use, but Sapien makes a version control system that I'm going to take a look at.

Most of the scripts I write automate certain things. What I've found over time is that I'm constantly stealing code from one script to use in another. Most of the time the syntax is even identical. I really should automate these snippets into full blown functions. I also think that it's time for me to make some tools for use by our helpdesk. We have a little command line batch file that predates me and is pretty popular within the department. So, for my first function, I'm going to create an uptime function, but I'm going to tie in a bunch of other handy information, too.

From the video, I gathered that [CmdletBinding()] is the cat's meow, and I can now confirm this. Using the Cmdletbinding tag allows me to use Write-Debug and Write-Verbose within my scripts, and then use -verbose and -debug options while calling the function to get that info (among a lot of other things).

Here's what I've come up with so far:

function Get-PCInfo {
  <#
  .SYNOPSIS
  Lists a number of useful pieces of information from a computer
  .DESCRIPTION
  Gets the following information:
  Logged on User
  Uptime
  CPU Usage
  Memory Usage
  C Drive Free Space
  .EXAMPLE
  Get-ComputerProperties <ComputerName>
  .PARAMETER computername
  The computer name to query. Just one.
  #>
  [CmdletBinding()]
  param
  (
    [Parameter(Mandatory=$True,
    ValueFromPipeline=$True,
    ValueFromPipelineByPropertyName=$True,
      HelpMessage='What computer name would you like to target?')]
    [Alias('host')]
    [ValidateLength(3,30)]
    [string[]]$computername

  )

  process {

    write-verbose "Beginning process loop"

    foreach ($computer in $computername) {
      Write-Verbose "Processing $computer"
      # use $computer to target a single computer

      #Ping Test
      $PingTest = test-connection $computer -quiet
      Write-Verbose "Ping Test Successful"

      If ($PingTest -eq $true){
          #Get Logged On User
          $LoggedOnUser = (Get-WMIObject -ComputerName $Computer -class Win32_ComputerSystem | select username).username

          #Get Uptime
          $lastboottime = (Get-WmiObject -Class Win32_OperatingSystem -computername $computer).LastBootUpTime
          $sysuptime = (Get-Date) – [System.Management.ManagementDateTimeconverter]::ToDateTime($lastboottime) 
          $Uptime = ($sysuptime.days).ToString() + " days, " + ($sysuptime.hours).ToString() + " hours, " + 
            ($sysuptime.minutes).ToString() + " minutes, " + ($sysuptime.seconds).ToString() + " seconds"
      
          #Get CPU Usage
          $AVGProc = (Get-WmiObject -computername $computer win32_processor | Measure-Object -property LoadPercentage -Average | Select Average).Average

          #Get Memory Usage
          $MemoryUsage = (Get-WMIObject -Class win32_operatingsystem -computername $computer | 
            Select-Object @{Name = "MemoryUsage"; Expression = {“{0:N2}” -f ((($_.TotalVisibleMemorySize - $_.FreePhysicalMemory)*100)/ $_.TotalVisibleMemorySize) }}).MemoryUsage

          #C Drive Free Space
          $CDriveFree = (Get-WMIObject -Class Win32_LogicalDisk -ComputerName $computer | where {$_.DeviceID -Like "C:"} | ForEach-Object {[math]::truncate($_.freespace / 1GB)}).ToString()

          # create an object with your output info
          $InfoItem = New-Object System.Object
          $InfoItem | Add-member -type NoteProperty -Name 'Logged On User' -value $LoggedOnUser
          $InfoItem | Add-member -type NoteProperty -Name 'Uptime' -value $Uptime
          $InfoItem | Add-member -type NoteProperty -Name 'CPU Usage (Load Percentage)' -value $AVGProc
          $InfoItem | Add-member -type NoteProperty -Name 'MemoryUsage (Percent)' -value $MemoryUsage
          $InfoItem | Add-member -type NoteProperty -Name 'C Drive Free (GB)' -value $CDriveFree
      
          #Display the Info
          $InfoItem
      } #End If
      Else {
        Write-Host "Unable to Ping Host"
      } #End Else
    } #End Foreach
  } #End Process
} #End Function