Recently, I discovered three PowerShell Core variables that could be very helpful when it comes to determining the operating system in PowerShell. PowerShell has become a cross-platfrom tool and can be installed on Linux or MacOs, too. So it could happen that you have to determine the operating system first before starting any other actions.

$IsWindows, $IsLinux, $IsMacOS

What I am talking about are these three PowerShell variables shipped with PowerShell Core 6 and PowerShell 7:

$IsLinux

$IsMacOS

$IsWindows

What can we do with it? For instance, if you want to implement a PowerShell script, it could make sense to determine the computers installed operating system first.

Here’s an example script that determines if the system is running Windows. The code is stored in $testos.

$testos = { If ($IsWindows)
{
Write-Warning 'System is running Windows. Script started.'
}
else
{
throw 'System is not Windows. Operation aborted.'
}
}

My local computer is running Windows, therefore the imaginary script would be executed.

&$testos

See you next time with PowerShell!