Fixing VirtualBox verr_supdrv_component_not_found when selecting bridged networking on OS X 10.9

While installing CentOS in VirtualBox (version 4.2.4) on OS X (version 10.9.1) I came across the following error message when selecting bridged networking

virtualbox verr_supdrv_component_not_found

The solution I found to this is to reload the VirtualBox kexts on the host operating system. To do this I used a script which I found here, I’ve put it on GitHub as a gist for future reference.

#!/bin/bash
# Reload Virtual Box Kexts

unload() {
        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() {
        sudo kextload /Library/Extensions/VBoxDrv.kext -r /Library/Extensions/
        sudo kextload /Library/Extensions/VBoxNetFlt.kext -r /Library/Extensions/
        sudo kextload /Library/Extensions/VBoxNetAdp.kext -r /Library/Extensions/
        sudo kextload /Library/Extensions/VBoxUSB.kext -r /Library/Extensions/
}

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