Brad Wilson

get-isadmin.ps1

Here's a simple way to tell if you're running as an administrator from within PowerShell:

$windowsIdentity = [System.Security.Principal.WindowsIdentity]::GetCurrent()
$windowsPrincipal = new-object 'System.Security.Principal.WindowsPrincipal' $windowsIdentity

return $windowsPrincipal.IsInRole("Administrators")

I like to use this right at the top of my startup profile to turn my window background dark red:

if ((get-isadmin) -and (-not $psISE)) {
    $Host.UI.RawUI.BackgroundColor = "DarkRed"
    clear
}

Since the raw UI can only use colors from the console, I also tweak my console's interpretation of dark red into (48,0,0) so that it's very dark, nearly black but still recognizably red. I also change my prompt color from green to yellow. It's very obvious looking at green on black vs. yellow on red that I'm in an admin prompt.

I check to make sure we're not running in the ISE, because the ISE runs a dark on light color scheme and doesn't paint the same way as the console version of PowerShell.

Calculating SHA1 in PowerShell

I can never remember where (or the name of) the random .EXE that I usually keep around for calculating SHA1 hashes is, and it seemed silly not to just spend the 10 minutes to write it in PowerShell. After all, everything you need is in .NET, right?

param([switch]$csv, [switch]$recurse)

[Reflection.Assembly]::LoadWithPartialName("System.Security") | out-null
$sha1 = new-Object System.Security.Cryptography.SHA1Managed
$pathLength = (get-location).Path.Length + 1

$args | %{
    if ($recurse) {
        $files = get-childitem -recurse -include $_
    }
    else {
        $files = get-childitem -include $_
    }

    if ($files.Count -gt 0) {
        $files | %{
            $filename = $_.FullName
            $filenameDisplay = $filename.Substring($pathLength)
            
            if ($csv) {
                write-host -NoNewLine ($filenameDisplay + ",")
            } else {
                write-host $filenameDisplay
            }

            $file = [System.IO.File]::Open($filename, "open", "read")
            $sha1.ComputeHash($file) | %{
                write-host -NoNewLine $_.ToString("x2")
            }
            $file.Dispose()

            write-host
            if ($csv -eq $false) {
                write-host
            }
        }
    }
}

pause.ps1

I needed a "pause" command for some of my PowerShell scripts, so this is what I ended up with. Enjoy.

param(
  [string]$message = "Press any key to continue..."
)

Write-Host -NoNewLine $Message

$Host.UI.RawUI.FlushInputBuffer()
do { $key = $Host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown").Character } while ([int]$key -eq 0)

Write-Host ""