Functions/Get-PSVersion.ps1

function Get-PSVersion 
{

<#
.SYNOPSIS
    Maps information from $PSVersionTable to a mapping table to retrieve friendly names for Windows PowerShell build numbers
  
.DESCRIPTION
    Get-PSVersion is a function to map information from $PSVersionTable to a mapping table in order to retrieve friendly names for Windows PowerShell build numbers.
    For example, if the build number is 5.0.10586.117, the returned friendly name will be 'Windows PowerShell 5 RTM 1512'.
    For remote computers, the function relies on PowerShell remoting.
    By default a mapping table bundled with the module is used a data source. The switch parameter -UpdatePSVersionData can be used to download the latest version.
  
A useful tip is to use a scheduled job to automatically update both the PSVersion module and the PSVersionData:
$ScheduledJobOption = New-ScheduledJobOption -RunElevated
$Trigger = New-JobTrigger -At 03:00:00 -Daily
 
Register-ScheduledJob -Name Update-PSVersion -ScriptBlock {
 
Update-Module -Name PSVersion -Force
Import-Module -Name PSVersion
Update-PSVersionData
 
} -Trigger $Trigger -ScheduledJobOption $ScheduledJobOption -RunNow
 
 
 
.PARAMETER ComputerName
    The remote computer(s) to retrieve PowerShell version information from.
 
.PARAMETER Credential
    Specifies a user account that has permission to perform this action. The default
    is the current user.
 
.PARAMETER UpdatePSVersionData
    Triggers the Update-PSVersionData function which will update the PowerShell version mapping table
 
.EXAMPLE
     Get-PSVersion
 
.EXAMPLE
     Get-PSVersion -UpdatePSVersionData
  
.EXAMPLE
     Get-PSVersion -ComputerName 'ComputerA','ComputerB'
 
.EXAMPLE
     'ComputerA','ComputerB | Get-PSVersion
 
.EXAMPLE
     Get-PSVersion -ComputerName 'ComputerA','ComputerB -Credential (Get-Credential)
 
.EXAMPLE
     Get-ADComputer -Filter 'operatingsystem -like "*Server*"' | Select-Object -ExpandProperty Name | Sort-Object -Property Name | Get-PSVersion
  
.INPUTS
    String
  
.OUTPUTS
    Selected.System.Collections.Hashtable
    System.Management.Automation.PSCustomObject
  
.NOTES
    Author: Jan Egil Ring
    Twitter: @JanEgilRing
#>


    [CmdletBinding()]
    param (
        [Parameter(Mandatory=$false,
                   ValueFromPipeline=$true,
                   ValueFromPipelineByPropertyName=$true
                   )]
        [string[]]$ComputerName=$env:computername,
        [System.Management.Automation.Credential()]$Credential = [System.Management.Automation.PSCredential]::Empty,
                [switch]$UpdatePSVersionData,
        [parameter(ParameterSetName = "ListVersion")]
        [switch]$ListVersion
    )

    BEGIN {        
        $Params = @{}


        If ($PSBoundParameters['Credential']) {
            $Params.Credential = $Credential
        }

        If ($PSBoundParameters['UpdatePSVersionData']) {
            Update-PSVersionData -ErrorAction SilentlyContinue
        }

            $functionpath = Split-Path -Path ${function:Get-PSVersion}.File
            $modulepath = Split-Path -Path $functionpath
            $mappingtablemodulepath = Join-Path -Path $modulepath -ChildPath 'PSVersionMappingTable.json'
            $mappingtableappdatapath = Join-Path -Path $env:LOCALAPPDATA\Microsoft\Windows\PowerShell -ChildPath 'PSVersionMappingTable.json'
            
            if (Test-Path -Path $mappingtableappdatapath) {

            Write-Verbose -Message "Found $mappingtableappdatapath, using this version..."
            $mappingtablepath = $mappingtableappdatapath

            } else {

            Write-Verbose -Message "$mappingtableappdatapath not found, using the mapping table which is bundled with the module..."
            $mappingtablepath = $mappingtablemodulepath

            }

            $mappingtable = Get-Content -Path $mappingtablepath -Raw | ConvertFrom-Json

            If ($PSBoundParameters['ListVersion']) {
            
            Write-Verbose -Message "Parameter Set: ListVersion"
            Write-Verbose -Message "mappingtablepath: $mappingtablepath"

            return $mappingtable
            break

             }

        
            $ComputerNames = @()

        }

    PROCESS {

        $ComputerNames += $ComputerName
   
   }
   END {

               If (-not ($PSBoundParameters['ComputerName']) -or $ComputerName -eq $env:computername -or $ComputerName -eq '127.0.0.1' -or $ComputerName -eq 'localhost' -or $ComputerName -eq '.') {
            
                 Write-Verbose -Message 'Parameter -ComputerName not specified, skipping PS Remoting and retriving information from localhost directly from $PSVersionTable'
                   
                   $PSVersion = $PSVersionTable.PSVersion.ToString()
                   $FriendlyName = ($mappingtable | Where-Object {$_.Name -eq $PSVersion}).FriendlyName
                  
                  
                  if (-not ($FriendlyName)) {
                  
                    Write-Verbose -Message 'FriendlyName not found in mappingtable, trying to update the local mapping table using Update-PSVersionData...'
                    
                    Update-PSVersionData -ErrorAction SilentlyContinue
                    
                    $mappingtable = Get-Content -Path $mappingtablepath -Raw | ConvertFrom-Json
                    $FriendlyName = ($mappingtable | Where-Object {$_.Name -eq $PSVersion}).FriendlyName

                    if (-not ($FriendlyName)) {

                      Write-Verbose -Message 'FriendlyName still not found in mappingtable, setting value to Unknown'

                      $FriendlyName = "Unknown $($_.PSVersion)"

                    } else {
                    
                      Write-Verbose -Message 'FriendlyName found after calling Update-PSVersionData'

                    }
                  }

                
                 $output =  [pscustomobject]@{
                   PSComputerName = $env:ComputerName
                   PSVersion = $PSVersionTable.PSVersion.ToString()
                   PSVersionFriendlyName = $FriendlyName
                 }

                 return $output

               }

   $Params.ComputerName = $ComputerNames
   
        
        Invoke-Command @Params {

             $PSVersionTable

            } -ErrorAction SilentlyContinue -ErrorVariable failed | Select-Object @{Name='PSComputerName';e={$_.PSComputerName}},@{Name='PSVersion';e={$_.PSVersion.ToString()}},@{Name='PSVersionFriendlyName';e={

                  $PSVersion = $_.PSVersion.ToString()
                  $FriendlyName = ($mappingtable | Where-Object {$_.Name -eq $PSVersion}).FriendlyName
                  
                  if ($FriendlyName) {

                  $FriendlyName

                  } else {

                  "Unknown $($_.PSVersion)"

                  }

                }
             }
        
       if ($failed) {

            foreach ($item in $failed)
            {

                [pscustomobject]@{
                PSComputerName = $item.TargetObject
                PSVersion = $null
                PSVersionFriendlyName = 'N/A - PS Remoting failed'

            }
            }


        }

   }
    
}