Uses portquiz to check outbound ports (you should check it out!)
note: abandoned and has bugs
go get github.com/nhooyr/outPorts
outPorts [-t n][-w n][-c] min[-max][sf]...
The flag -t allows you to change the timeout for each connection in seconds, default is 0. The flag -w allows you to change the number of workers used (concurrent TCP requests), so if you're getting false positives, use less. Default is 1024. The flag -c allows for color/bold output which makes it easier to see.
check from ports 1 to 65535
check from ports 20-30 and then 40-50
outPorts 20-30 40-50
check from ports 20-10 and then 40-10
outPorts 20-10 40-10
check port 25
check from ports 1-65535 and only display failure
check from ports 20-25 and only display success
check from ports 20-25 and only display success, then check from ports 30-35 and only display failure, then check from ports 40-50 and display both.
outPorts 20-25s 30-35f 40-50
to see documentation on the terminal
it works asynchronously so the output will not always be in order, but it is very fast.