<#
.SYNOPSIS
	Wakes up a computer using Wake-on-LAN
.DESCRIPTION
	This PowerShell script sends a magic UDP packet to a computer to wake him up (requires the target computer to have Wake-on-LAN activated).
.PARAMETER macAddr
	Specifies the host's MAC address (e.g. 11:22:33:44:55:66)
.PARAMETER ipAddr
	Specifies the host's IP address or subnet address (e.g. 192.168.0.255)
.PARAMETER udpPort
	Specifies the UDP port (9 by default)
.PARAMETER numTimes
	Specifies # of times to send the packet (3 by default)
.EXAMPLE
	PS> ./wake-up.ps1 11:22:33:44:55:66 192.168.100.100
	✔️ Magic packet sent 3x to IP 192.168.100.100, UDP port 9 - wait a minute until the computer fully boots up.
.LINK
	https://github.com/fleschutz/PowerShell
.NOTES
	Author: Markus Fleschutz | License: CC0
#>

param([string]$macAddr = "", [string]$ipAddr = "", [int]$udpPort = 9, [int]$numTimes = 3)
	
function Send-WOL { param([string]$macAddr, [string]$ipAddr, [int]$udpPort) 
	$broadcastAddr = [Net.IPAddress]::Parse($ipAddr) 
  
	$macAddr = (($macAddr.replace(":","")).replace("-","")).replace(".","") 
	$target = 0,2,4,6,8,10 | % {[convert]::ToByte($macAddr.substring($_,2),16)} 
	$packet = (,[byte]255 * 6) + ($target * 16) 
  
	$UDPclient = New-Object System.Net.Sockets.UdpClient 
	$UDPclient.Connect($broadcastAddr, $udpPort) 
	[void]$UDPclient.Send($packet, 102)  
} 

try {
	if ($macAddr -eq "" ) { $macAddr = Read-Host "Enter the host's MAC address, e.g. 11:22:33:44:55:66" }
	if ($ipAddr -eq "" ) { $ipAddr = Read-Host "Enter the host's IP or subnet address, e.g. 192.168.0.255" }

	for ($i = 0; $i -lt $numTimes; $i++) {
		Send-WOL $macAddr.Trim() $ipAddr.Trim() $udpPort
		Start-Sleep -milliseconds 100	
	}
	"✔️ Magic packet sent $($numTimes)x to IP $ipAddr, UDP port $udpPort - wait a minute until the computer fully boots up."
	exit 0 # success
} catch {
	"⚠️ Error in line $($_.InvocationInfo.ScriptLineNumber): $($Error[0])"
	exit 1
}
