The showvminfo command shows information about a particular virtual machine. This is the same information as VBoxManage list vms would show for all virtual machines.

You will get information similar to the following:

$ VBoxManage showvminfo "Windows XP"
VirtualBox Command Line Management Interface Version 2.0.6
(C) 2005-2008 Sun Microsystems, Inc.
All rights reserved.

Name:            Windows XP
Guest OvS:        Other/Unknown
UUID:            1bf3464d-57c6-4d49-92a9-a5cc3816b7e7
Config file:     /home/username/.VirtualBox/Machines/Windows XP/Windows XP.xml
Memory size:     128MB
VRAM size:       8MB
Boot menu mode:  message and menu
ACPI:            on
IOAPIC:          off
Hardw. virt.ext: off
State:           powered off
Floppy:          empty
DVD:             empty
NIC 1:           disabled
NIC 2:           disabled
NIC 3:           disabled
NIC 4:           disabled
Audio:           disabled (Driver: Unknown)
VRDP:            disabled
USB:             disabled

USB Device Filters:
<none>

Shared folders:
<none>