Checks if the Extension Pack version matches the installed VirtualBox version and if not, delete the Extension Pack, downloads and installs the new one.

updatevirtualboxextions

#! /bin/bash
#
#: Title       : updateVboxExt
#: Date Created: Fri May 13 13:54:26 PDT 2011 
#: Last Edit   : Fri May 13 14:34:37 PDT 201
#: Author      : please_try_again 
#: Version     : 1.0
#: Description : Install or update VirtualBox Extension pack

pkg_sit="http://download.virtualbox.org/virtualbox/"
ext_nam="Oracle VM VirtualBox Extension Pack"
pkg_ext="vbox-extpack"
#

which vboxmanage > /dev/null 2>&1 || exec echo "vboxmanage not found"
ver=$(vboxmanage -v)

pkg_nam="${ext_nam// /_}"
pkg_tgz="${pkg_nam}.tgz"
pkg_ver="${ver%%r*}"
pkg_blt="${ver##*r}"
pkg_url="${pkg_sit}${pkg_ver}/${pkg_nam}-${pkg_ver}-${pkg_blt}.${pkg_ext}"

# check if ExtensionPack for current VirtualBox version already install
N=$(vboxmanage list extpacks | grep -c -e "$pkg_ver" -e "$pkg_blt")
[ $N -ge 2 ] && exec echo "Extension Pack already installed"

# Deinstall older versions ExtensionPack if any
vboxmanage list extpacks | grep -q "$ext_nam" && { 
  oldver=$(vboxmanage list extpacks | awk 'BEGIN {ORS="r"} ; /Version:|Revision/ { print $2 }' | sed 's|r$||')
	echo "- uninstalling $ext_nam $oldver"
	vboxmanage extpack uninstall "$ext_nam"
}

# download VirtualBox Extension Pack
echo "- Downloading $pkg_url ..."
wget $pkg_url -O $pkg_tgz

# Install newer ExtensionPack version
if [ -f ./$pkg_tgz ] ; then
	echo "- installing $ext_nam $ver"
	vboxmanage extpack install $pkg_tgz
else
	echo "No extension pack found"
fi