Added check-ipv6-address.ps1

Scripts/check-ipv6-address.ps1

@@ -0,0 +1,47 @@
+#!/bin/powershell
+<#
+.SYNTAX         ./check-ipv6-address.ps1 [<address>]
+.DESCRIPTION	checks the given IPv6 address for validity
+.LINK		https://github.com/fleschutz/PowerShell
+.NOTES		Author:	Markus Fleschutz / License: CC0
+#>
+
+param($Address = "")
+
+function IsIPv6AddressValid { param([string]$IP)
+    $IPv4Regex = '(((25[0-5]|2[0-4][0-9]|[0-1]?[0-9]{1,2})\.){3}(25[0-5]|2[0-4][0-9]|[0-1]?[0-9]{1,2}))'
+    $G = '[a-f\d]{1,4}'
+    $Tail = @(":",
+    "(:($G)?|$IPv4Regex)",
+    ":($IPv4Regex|$G(:$G)?|)",
+    "(:$IPv4Regex|:$G(:$IPv4Regex|(:$G){0,2})|:)",
+    "((:$G){0,2}(:$IPv4Regex|(:$G){1,2})|:)",
+    "((:$G){0,3}(:$IPv4Regex|(:$G){1,2})|:)",
+    "((:$G){0,4}(:$IPv4Regex|(:$G){1,2})|:)")
+    [string] $IPv6RegexString = $G
+    $Tail | foreach { $IPv6RegexString = "${G}:($IPv6RegexString|$_)" }
+    $IPv6RegexString = ":(:$G){0,5}((:$G){1,2}|:$IPv4Regex)|$IPv6RegexString"
+    $IPv6RegexString = $IPv6RegexString -replace '\(' , '(?:' # make all groups non-capturing
+    [regex] $IPv6Regex = $IPv6RegexString
+    if ($IP -imatch "^$IPv6Regex$") {
+    	return $true
+    } else {
+    	return $false
+    }
+}
+
+try {
+	if ($Address -eq "" ) {
+		$Address = read-host "Enter IPv6 address to validate"
+	}
+	if (IsIPv6AddressValid $Address) {
+		write-host -foregroundColor green "OK - IPv6 address $Address is valid"
+		exit 0
+	} else {
+		write-warning "Invalid IPv6 address: $Address"
+		exit 1
+	}
+} catch {
+	write-error "ERROR in line $($_.InvocationInfo.ScriptLineNumber): $($Error[0])"
+	exit 1
+}