Get Common Data

While judging entries in this year's Scripting Games I realized there were some common properties that were repeatedly used. This got me thinking about a simple way to retrieve that information with a single command Then you could access the data values from within your script. I've put together a relatively simply function called Get-Common that you might find helpful.

There's nothing fancy about this function.

Function Get-Common {

[cmdletbinding()]

Param()

Set-StrictMode -Version Latest

Write-Verbose "Starting $($myinvocation.mycommand)"

#test if user is an administrator
Write-Verbose "Testing for admin rights"
$currentUser = [Security.Principal.WindowsIdentity]::GetCurrent()
$IsAdmin=(New-Object Security.Principal.WindowsPrincipal $currentUser).IsInRole([Security.Principal.WindowsBuiltinRole]::Administrator)

Write-Verbose "Get Username"
#get username from the environmental variable
$username=$env:username

Write-Verbose "Get Computername"
#get computername from the environmental variable
$computername=$env:computername

Write-Verbose "Get Domain name"
#get domain name from the environmental variable
$domain=$env:userdomain

Write-Verbose "Get DNS Domain name"
#get domain DNS name from the environmental variable
#this may not be found on older computers
if ($env:userDNSDomain)
{
$dnsDomain=$env:userdnsdomain
}
else
{
$dnsDomain=$Null
}
Write-Verbose "Get Operating System"
#get operating system from WMI
$os=Get-WmiObject -Class Win32_OperatingSystem

Write-Verbose "Get last boot up time"
#use the WMI ConvertToDateTime method
$boot=$os.ConvertToDateTime($os.LastBootUpTime)

Write-Verbose "Write object"
#write custom object to the pipeline
New-Object -TypeName PSObject -Property @{
Username=$username
Computername=$computername
IsAdmin=$IsAdmin
Domain=$domain
DNSDomain=$DNSDomain
OperatingSystem=$os.caption
LastBoot=$boot
PSHost=$host.name
PSVersion=$host.version
}

Write-Verbose "Ending $($myinvocation.mycommand)"

} #end function

I gathers a number of what I think of as common values such as username, computername, PowerShell host and whether the user is running as an administrator. The function writes a custom object to the pipeline, using New-Object.

PS S:\> get-common

Computername : SERENITY
Username : Jeff
LastBoot : 4/15/2011 2:34:19 PM
IsAdmin : True
DNSDomain :
OperatingSystem : Microsoft Windows 7 Ultimate
PSHost : ConsoleHost
Domain : SERENITY
PSVersion : 2.0

Assuming you have dot sourced the function, you could use it in your script like this:

$data=Get-Common

if ($data.IsAdmin)
{
$wsmanPort=(dir WSMan:\localhost\Listener -rec | where {$_.name -eq "Port"}).value

$uptime=(Get-Date) - $data.lastBoot
if ($data.OperatingSystem -match "Windows 7")
{
$Win7=$True
}
else
{
$Win7=$False
}
New-Object -TypeName PSObject -Property @{
Computername=$data.computername
Uptime=$uptime
IsWin7=$Win7
WSManPort=$wsmanPort
}

}
else
{
Write-Warning "You must be an administrator"
}

Maybe this will help simplify your scripts or maybe it won't. Of course you can easily extend it to include other core or common data you use frequently in your scripts. If there's something you add, I'm curious to learn what it is.

Download Get-Common.

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