Get all ports you can access from inside of a network to the outside. Useful if ports are blocked by your sysadmin and you need to find out what ports you can put your services on to access them.

get-open-ports.sh

#!/bin/bash

function scan() {
    # stdin will be parsed by the script
    # stderr is just for debugging purposes and to see the process while running the script
    curl "http://portquiz.net:$1" &>/dev/null && echo "$i" && echo "$i" >&2
}

function scanAll() {
    for i in {0..69420}; do
        scan $i &
    done

    # wait for the started subshells to exit
    wait
}

RESULT="$(echo "$(scanAll)" | sort -n | tr '\n' ',')"
echo ${RESULT::-1}