Finds all running Vagrant instances, recursively, from with in the current folder. It then shuts them down, deletes the VM, and removes the .vagrant file.

destroy-vagrant.sh

#!/usr/bin/env bash
for config in `find . -type f -name .vagrant`
do
  uuid=`cat "$config" | php -r 'echo json_decode(fgets(STDIN))->active->default;'`
  if VBoxManage showvminfo $uuid > /dev/null 2>&1; then
    if VBoxManage showvminfo $uuid --machinereadable | egrep -q 'VMState="running|paused|stuck"'; then
      VBoxManage controlvm $uuid poweroff
    fi
    VBoxManage unregistervm $uuid --delete
    rm -f "$config"
  fi
done