Examples/DNSLookup.ps1
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<#PSScriptInfo
.NAME DNSLookup .VERSION 1.0.1 .DESCRIPTION Example PowerShell to Verify if an Internet Domain Name is Valid. .GUID 26e6e82b-7b29-4fa5-b56a-51ce0d1d1e80 .AUTHOR DecimalZero .COMPANYNAME NestLink .COPYRIGHT Copyright (C) DecimalZero. All rights reserved. .TAGS Test-InternetConnection InternetConnection Check Internet DNSLookup DNS Lookup PowerShell Console Install Module Parameters String Switch Function Help Error Azure REST API APIs DecimalZero .LICENSEURI https://github.com/DecimalZero/Dz.Test-InternetConnection/blob/main/LICENSE .PROJECTURI https://github.com/DecimalZero/Dz.Test-InternetConnection .ICONURI https://github.com/DecimalZero/Dz.Test-InternetConnection/tree/main/Images/Test-InternetConnection.png .RELEASENOTES https://github.com/DecimalZero/Dz.Test-InternetConnection/blob/main/README.md .REQUIRESMODULE N/A .EXTERNALMODULEDEPENDENCIES N/A .REQUIREDSCRIPTS N/A .EXTERNALSCRIPTDEPENDENCIES N/A .PRIVATEDATA N/A .PARAMETERS [[-DnsDomainName] <String>] [[-Help] <SwitchParameter>] [[-Debug] <SwitchParameter>] #> Param ( [String]$DnsDomainName, [Switch]$Help, [Switch]$Debug ) # Set powershell window title $Host.UI.RawUI.WindowTitle = 'DNS Lookup' # Check if dns domain name parameter is blank If ($DnsDomainName -eq ''){ # Set dns domain name variable $DnsDomainName = 'azure.microsoft.com' } Function WriteErrorDetails{# Write error details to powershell console # Write error message Write-Host ((' ') + ($error[0].ToString())) -ForegroundColor Red; Write-Host # Write powershell source code postition message Write-Host ((' ') + ($error[0].InvocationInfo.PositionMessage)) -ForegroundColor Red; Write-Host } Function Check-Modules{# Check if required powershell gallery modules are installed # Check to see if required powershell dz.write-message module is installed Write-Host;Write-Host ('Checking if Required PowerShell Module Dz.Write-Message is Installed...') -ForegroundColor Yellow If (Get-Module -ListAvailable -Name Dz.Write-Message) { # Import module dz.write-message Import-Module Dz.Write-Message # Write message utilizing the imported dz.write-message module Write-Message (('PowerShell Module |Dz.Write-Message v') + (((Get-Module -Name Dz.Write-Message -ListAvailable).ModuleBase).Split('\')[7]) + ('| is Installed...')) 'Cyan|Green|Cyan' -Indent1 }Else { # Install module dz.write-message Write-Host ' - Installing PowerShell Module Dz.Write-Message...' -ForegroundColor Cyan Try {# Try installing the required powershell module Install-Module -Name Dz.Write-Message -Force # Import module dz.write-message Import-Module Dz.Write-Message # Write message utilizing the imported dz.write-message module Write-Message (('PowerShell Function |Write-Message v') + (((Get-Module -Name Dz.Write-Message -ListAvailable).ModuleBase).Split('\')[7]) + ('| is Installed...')) 'Cyan|Green|Cyan' -Indent1 }Catch { # Display error message Write-Host Write-Host ' WARNING: Something Went Wrong. Unable to Install' -ForegroundColor Red Write-Host ' or Import PowerShell Module Dz.Write-Message!!' -ForegroundColor Red Write-Host # Check if debug switch equals true If ($Debug){ # Call function to write error details to powershell console WriteErrorDetails } # Break out of powershell script Break } } } Function Help-Message{# Custom help message # Display custom help message Write-Message 'DNSLookup.ps1 is a quick way to check if an Internet Domain Name is valid.' -Indent2 -AddLineBefore -AddLineAfter Write-Message '_____________________________________________________________________________________________' -Indent2 -AddLineAfter Write-Message 'New to PowerShell? This PowerShell example is a great way to learn the following...' -Indent2 -AddLineBefore -AddLineAfter Write-Message '1.) How to use Parameters' -Indent2 Write-Message '2.) How to use a PowerShell String' -Indent2 Write-Message '3.) How to use a PowerShell Switch' -Indent2 Write-Message '4.) How to Pass a Variable to a Function' -Indent2 Write-Message '5.) How to Write a PowerShell Help Function' -Indent2 Write-Message '6.) How to Write PowerShell Error Details' -Indent2 Write-Message '7.) How to Automatically Check for Installed Modules' -Indent2 Write-Message '8.) How to Automatically Install PowerShell Modules' -Indent2 Write-Message '9.) How to Perform an Internet DNS Lookup' -Indent2 -AddLineAfter Write-Message '_____________________________________________________________________________________________' -Indent2 -AddLineAfter Write-Message 'EXAMPLES:' -Indent2 -AddLineBefore Write-Message '.\Test-InternetConnection.ps1' -Indent2 Write-Message '.\Test-InternetConnection.ps1 -Help' -Indent2 Write-Message '.\Test-InternetConnection.ps1 Google.com' -Indent2 Write-Message '.\Test-InternetConnection.ps1 SomeFakeDomainName.com' -Indent2 Write-Message '.\Test-InternetConnection.ps1 SomeFakeDomainName.com -Debug' -Indent2 -AddLineAfter # Exit script Exit } Function TestInternetConnection{# Test internet connectivity Param ( [String]$DnsDomainName ) Try { # Test to see if dns domain name can be resolved Resolve-DnsName -Name $DnsDomainName -Type NS -DnsOnly -ErrorAction Stop | Where-Object Section -eq Additional }Catch { # Display error message Write-Host Write-Host ' WARNING: Something Went Wrong. No Internet Connection!!' -ForegroundColor Red Write-Host ' Please check your Network Cable or Wifi and Try Again.' -ForegroundColor Red Write-Host # Check if debug switch equals true If ($Debug){ # Call function to write error details to powershell console WriteErrorDetails } # Break out of powershell script Break } } # Check for help switch If ($Help){ # Call function to display custom help message Help-Message } # Call function to check if required powershell modules are installed Check-Modules # Call function to test internet connectivity TestInternetConnection $DnsDomainName # Display message if only successful Write-Message (('DNS Lookup for Domain Name |') + ($DnsDomainName) + ('| was Successful!')) 'Cyan|Green|Cyan' -Indent1 Write-Message ' For Help, Type .\Test-InternetConnection.ps1 -Help' -AddLineBefore -AddLineAfter |