quick VBox (headless) admin script

vm_admin.sh

#!/bin/bash
# cedric
# XXX: this is how I prefer to stop a VM, change this at will
PREFERRED_STOP_METHOD="acpipowerbutton"

function perror() { echo -e $@ 1>&2; }
function vm_exists() {
	local VM=$1
	VBoxManage showvminfo "${VM}"  >/dev/null 2>&1
	return $?
}

#Â ACTIONS
function start() {
	echo "[INFO] Starting \`${VMNAME}\`..."
	(
		cd /tmp && \
			nohup VBoxHeadless -startvm "${VMNAME}" &
	) > /dev/null 2>&1
	return 0
}
function stop() {
	echo "[INFO] Stopping \`${VMNAME}\`..."
	VBoxManage controlvm "${VMNAME}" ${PREFERRED_STOP_METHOD}
	return 0
}
function pause() {
	echo "[INFO] Pausing \`${VMNAME}\`..."
	VBoxManage controlvm "${VMNAME}" pause
	return 0
}
function resume() {
	echo "[INFO] Resuming \`${VMNAME}\`..."
	VBoxManage controlvm "${VMNAME}" resume
	return 0
}
function status() {
	local STATUS=$( VBoxManage showvminfo "${VMNAME}"|egrep '^State:'|sed -E 's/State:\s+//g' )
	printf "[INFO] %s\n" "$STATUS"
	return 0
}
function _is_status() {
	local DESIRED=$1
	status | grep -q "${DESIRED}" >/dev/null
	return $?
}


if [[ ${#@} -lt 2 ]];then
	if [ ${#@} -eq 1 ] && [ "$1" == "list" ];then
		VBoxManage list vms
		exit 0
	fi
	perror "Usage:\t$0 <vm> <start|stop|pause|resume|status>"
	perror "\t$0 list"
	exit 1
fi

VMNAME=$1
ACTION=$2

if ! vm_exists "$VMNAME";then
	perror "[ERROR] VM \`${VMNAME}\` doesn't exists."
	exit 2
fi

case $ACTION in
	stop)
		_is_status "running"
		if [ $? -ne 0 ];then
			perror "[ERROR] VM is not running!"
			exit 3
		fi
		stop
		;;
	start)
		_is_status "powered off"
		if [ $? -ne 0 ];then
			perror "[ERROR] VM is not powered off!"
			exit 3
		fi
		start
		;;
	pause)
		_is_status "running"
		if [ $? -ne 0 ];then
			perror "[ERROR] VM is not running!"
			exit 3
		fi
		pause
		;;
	resume)
		_is_status "paused"
		if [ $? -ne 0 ];then
			perror "[ERROR] VM is not paused!"
			exit 3
		fi
		resume
		;;
	status)
		status
		;;
	*)
		perror "[ERROR] Unexistent action."
		exit 3
		;;
esac
exit 0

vm_status_all.sh

#!/bin/bash
VMS=$( ./vm_admin.sh list | grep -Eo "\"(.+?)\"" | tr -d '"')
IFS=$'\n' 
for vm in ${VMS[*]};do
	echo -en "VM: $vm\n\t"
	./vm_admin.sh "${vm}" status
done