Linux – Size command in linux

netstat -lat gives the complete list of listening and established ports.

When a port is not on any of those states doesn't exist for the system, so you won't find a command that shows the list of unused ports.

Keep in mind that there are 65535 ports, so anything that isn't on netstat -lat is an unused port.

The following bash script will do a simple scan of tcp ports, and let you know which are open and which are closed :

#!/bin/bash
IP=$1
first_port=$2
last_port=$3
function scanner

{
for ((port=$first_port; port<=$last_port; port++))
        do
                (echo >/dev/tcp/$IP/$port)> /dev/null 2>&1 && echo $port open || echo "$port closed"
        done
}

scanner

If you save it as portscan.sh then it must be run as ./portscan.sh IP first_port last_port, for example: ./portscan 127.0.0.1 20 135 will scan the local equipment from ports 20 to 135

You cannot natively run a program for Linux under Windows. They are completely different operating systems.

However, there are methods you can try to run the program:

1. Recompile the program on Windows to get a native executable
2. Install the Windows Subsystem for Linux and run the program in that environment
3. Install Linux in a virtual machine and run the program in that environment
4. Install Cygwin or MinGW and recompile and run in that environment
5. Use a cross compiler

Granted, depending on the nature of the program and its dependencies, it might not be possible to run in another environment without additional software, modifications to the source code, or at all.