4 Guest Additions To accomplish this, VirtualBox establishes a private communication channel between the VirtualBox Guest Additions and the host, and software on both sides can use this channel to exchange string data for arbitrary purposes. Guest properties are simply string keys to which a value is attached. They can be set (written to) by either the host and the guest, and they can also be read from both sides. In addition to establishing the general mechanism of reading and writing values, a set of predefined guest properties is automatically maintained by the VirtualBox Guest Additions to allow for retrieving interesting guest data such as the guest’s exact operating system and service pack level, the installed version of the Guest Additions, users that are currently logged into the guest OS, network statistics and more. These predefined properties are all prefixed with /VirtualBox/ and organized into a hierarchical tree of keys. Some of this runtime information is shown when you select “Session Information Dialog” from a virtual machine’s “Machine” menu. A more flexible way to use this channel is via the VBoxManage guestproperty command set see chapter 8.28, VBoxManage guestproperty, page 126 for details. For example, to have all the available guest properties for a given running VM listed with their respective values, use this: $ VBoxManage guestproperty enumerate "Windows Vista III" VirtualBox Command Line Management Interface Version 4.0.4 (C) 2005-2011 Oracle Corporation All rights reserved. Name: /VirtualBox/GuestInfo/OS/Product, value: Windows Vista Business Edition, timestamp: 1229098278843087000, flags: Name: /VirtualBox/GuestInfo/OS/Release, value: 6.0.6001, timestamp: 1229098278950553000, flags: Name: /VirtualBox/GuestInfo/OS/ServicePack, value: 1, timestamp: 1229098279122627000, flags: Name: /VirtualBox/GuestAdd/InstallDir, value: C:/Program Files/Oracle/VirtualBox Guest Additions, timestamp: 1229098279269739000, flags: Name: /VirtualBox/GuestAdd/Revision, value: 40720, timestamp: 1229098279345664000, flags: Name: /VirtualBox/GuestAdd/Version, value: 4.0.4, timestamp: 1229098279479515000, flags: Name: /VirtualBox/GuestAdd/Components/VBoxControl.exe, value: 4.0.4r40720, timestamp: 1229098279651731000, flags: Name: /VirtualBox/GuestAdd/Components/VBoxHook.dll, value: 4.0.4r40720, timestamp: 1229098279804835000, flags: Name: /VirtualBox/GuestAdd/Components/VBoxDisp.dll, value: 4.0.4r40720, timestamp: 1229098279880611000, flags: Name: /VirtualBox/GuestAdd/Components/VBoxMRXNP.dll, value: 4.0.4r40720, timestamp: 1229098279882618000, flags: Name: /VirtualBox/GuestAdd/Components/VBoxService.exe, value: 4.0.4r40720, timestamp: 1229098279883195000, flags: Name: /VirtualBox/GuestAdd/Components/VBoxTray.exe, value: 4.0.4r40720, timestamp: 1229098279885027000, flags: Name: /VirtualBox/GuestAdd/Components/VBoxGuest.sys, value: 4.0.4r40720, timestamp: 1229098279886838000, flags: Name: /VirtualBox/GuestAdd/Components/VBoxMouse.sys, value: 4.0.4r40720, timestamp: 1229098279890600000, flags: Name: /VirtualBox/GuestAdd/Components/VBoxSF.sys, value: 4.0.4r40720, timestamp: 1229098279893056000, flags: Name: /VirtualBox/GuestAdd/Components/VBoxVideo.sys, value: 4.0.4r40720, timestamp: 1229098279895767000, flags: Name: /VirtualBox/GuestInfo/OS/LoggedInUsers, value: 1, timestamp: 1229099826317660000, flags: Name: /VirtualBox/GuestInfo/OS/NoLoggedInUsers, value: false, timestamp: 1229098455580553000, flags: Name: /VirtualBox/GuestInfo/Net/Count, value: 1, timestamp: 1229099826299785000, flags: Name: /VirtualBox/HostInfo/GUI/LanguageID, value: C, timestamp: 1229098151272771000, flags: Name: /VirtualBox/GuestInfo/Net/0/V4/IP, value: 192.168.2.102, 67