random-string.ps1

#Random string generation for passwords etc
#defaults to all printable ascii
#works either inclusively, building a character palette up from zero with switches like -Numbers
#or exclusively, starting with all printable ascii and removing characters, as with -NoNumbers
#`Random-String -Numbers $False` and `Random-String -NoNumbers` work the same
function Random-String {
	[CmdletBinding()]
	Param(
		[Int]$Length = 16,
		[Switch]$Letters,
		[Switch]$NoLetters,
		[Switch]$Symbols,
		[Switch]$NoSymbols,
		[Switch]$Numbers,
		[Switch]$NoNumbers,
		[Switch]$Alphanumeric,
		[Switch]$Lowercase,
		[Switch]$Uppercase
	)
	If($Length -eq 0) {
		#?????
		return
	}
	#No preferences
	If(!$Letters -and
		!$Symbols -and
		!$Numbers -and
		!$Alphanumeric -and
		!$Lowercase -and !$Uppercase) {
		#Defaults
		$Letters = [Switch]::Present
		$Symbols = [Switch]::Present
		$Numbers = [Switch]::Present
	}
	If($Alphanumeric) {
		$Letters = [Switch]::Present
		$Numbers = [Switch]::Present
	}
	$Symbols = ($Symbols -and !$NoSymbols)
	$Numbers = ($Numbers -and !$NoNumbers)
	$Letters = ($Letters -and !$NoLetters)
	$Palette = ""
	If($Alphanumeric) {
		$Letters = [Switch]::Present
		$Numbers = [Switch]::Present
	}
	If($Letters) {
		If($Lowercase -and !$Uppercase) {
			$Palette += "abcdefghijklmnopqrstuvwxyz"
		} ElseIf($Uppercase -and !$Lowercase) {
			$Palette += "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
		} Else {
			$Palette += "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
		}
	}
	If($Numbers) { $Palette += "0123456789" }
	If($Symbols) { $Palette += "!`"#`$%&'()*+,-./:;<=>?@[\]^_``{|}~" }
	0..($Length - 1) | %{
		$str += $Palette[(Get-Random -Maximum $Palette.Length)]

	}
	return $str
}