Refer: http://www.virtualbox.org/manual/ch08.html#vboxmanage-list
"C:\Program Files\Oracle\VirtualBox\vboxmanage" list vms
"C:\Program Files\Oracle\VirtualBox\vboxmanage" list runningvms
"C:\Program Files\Oracle\VirtualBox\VBoxHeadless.exe" --startvm "Ubuntu-13.04"
"C:\Program Files\Oracle\VirtualBox\vboxmanage" controlvm "Ubuntu-13.04" savestate
Ubuntu 14.04
$ /usr/bin/VBoxManage list vms
$ /usr/bin/VBoxManage list runningvms$ /usr/bin/VBoxHeadless -startvm "VBox-Win10"
$ /usr/bin/VBoxManage controlvm "VBox-Win10" savestate