Script to load kernel extensions in order to allow `brew cask reinstall --force virtualbox`

kernel_extensions.sh

#!/bin/bash

unload() {
        if [ `ps -ef | grep -c VirtualBox$` -ne 0 ]
        then
                echo "VirtualBox still seems to be running. Please investigate!!"
                exit 1;
        elif [ `ps -ef | grep -c [V]ir` -gt 0 ]
        then
                echo "Stopping running processes before unloading Kernel Extensions"
                ps -ef | grep [V]ir | awk '{print $2}' | xargs kill
        fi
        echo "Unloading Kernel Extensions"
        kextstat | grep "org.virtualbox.kext.VBoxUSB" > /dev/null 2>&1 && sudo kextunload -b org.virtualbox.kext.VBoxUSB
        kextstat | grep "org.virtualbox.kext.VBoxNetFlt" > /dev/null 2>&1 && sudo kextunload -b org.virtualbox.kext.VBoxNetFlt
        kextstat | grep "org.virtualbox.kext.VBoxNetAdp" > /dev/null 2>&1 && sudo kextunload -b org.virtualbox.kext.VBoxNetAdp
        kextstat | grep "org.virtualbox.kext.VBoxDrv" > /dev/null 2>&1 && sudo kextunload -b org.virtualbox.kext.VBoxDrv
}

load() {
        echo "Loading Kernel Extentions"
        sudo kextload "/Library/Application Support/VirtualBox/VBoxDrv.kext" -r "/Library/Application Support/VirtualBox/"
        sudo kextload "/Library/Application Support/VirtualBox/VBoxNetAdp.kext" -r "/Library/Application Support/VirtualBox/"
        sudo kextload "/Library/Application Support/VirtualBox/VBoxNetFlt.kext" -r "/Library/Application Support/VirtualBox/"
        sudo kextload "/Library/Application Support/VirtualBox/VBoxUSB.kext" -r "/Library/Application Support/VirtualBox/"
}

case "$1" in
        unload|remove)
                unload
                ;;
        load)
                load
                ;;
        *|reload)
                unload
                load
                ;;
esac