Output the total number of currently running VirtualBox VMs, along with their names. This has been written with Vagrant in mind, where VMs are named `hostname_default_xxxxxxxxx` where only the value of `hostname` is relevant/recognisable.

vbox-status-check.sh

#!/bin/bash

machines=()

for machine in `VBoxManage list runningvms|cut -d" " -f 1`; do
  machines+=("$machine")
done

if [ ${#machines[@]} -eq 1 ]; then
  machinename=$(echo ${machines[@]} | cut -d'_' -f 1)
  echo "1 VM running: $machinename"
elif [ ${#machines[@]} -gt 1 ]; then
  echo "${#machines[@]} VMs running:"
  for machine in ${machines[@]}; do
    machinename=$(echo ${machine} | cut -d'_' -f 1)
    echo "$machinename\""
  done
else
    echo "No VMs running"
fi

I'll soon be looking at implementing this alongside Vagrant 1.6's 'global status' feature (rather than relying on VBox): http://www.vagrantup.com/blog/feature-preview-vagrant-1-6-global-status.html