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<topic xml:lang="en-us" id="guestadd-guestprops">
  <title>Guest Properties</title>
  
  <body>
    <p>
      <ph conkeyref="vbox-conkeyref-phrases/product-name"/> enables requests of some properties from a running
      guest, provided that the <ph conkeyref="vbox-conkeyref-phrases/product-name"/> Guest Additions are
      installed and the VM is running. This provides the following
      advantages:
    </p>
    <ul>
      <li>
        <p>
          A number of predefined VM characteristics are automatically
          maintained by <ph conkeyref="vbox-conkeyref-phrases/product-name"/> and can be retrieved on the host.
          For example, to monitor VM performance and statistics.
        </p>
      </li>
      <li>
        <p>
          Arbitrary string data can be exchanged between guest and host.
          This works in both directions.
        </p>
      </li>
    </ul>
    <p>
      To accomplish this, <ph conkeyref="vbox-conkeyref-phrases/product-name"/> establishes a private
      communication channel between the <ph conkeyref="vbox-conkeyref-phrases/product-name"/> 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,
      or written to, by either the host and the guest. They can also be
      read from both sides.
    </p>
    <p>
      In addition to establishing the general mechanism of reading and
      writing values, a set of predefined guest properties is
      automatically maintained by the <ph conkeyref="vbox-conkeyref-phrases/product-name"/> 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 <codeph>/VirtualBox/</codeph>
      and organized into a hierarchical tree of keys.
    </p>
    <p>
      Some of this runtime information is shown when you select
      <b outputclass="bold">Session Information Dialog</b> from a
      virtual machine's <b outputclass="bold">Machine</b> menu.
    </p>
    <p> A more flexible way to use this channel is with the <userinput>VBoxManage guestproperty</userinput> command. See <xref href="../cli_topics/vboxmanage-guestproperty.dita"/>. For example, to have <i>all</i> the available guest properties for a given running VM listed with their respective values, use this command: </p>
    <pre xml:space="preserve">$ VBoxManage guestproperty enumerate "Windows Vista III"
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: <varname>version-number</varname>,
    timestamp: 1229098279479515000, flags:
Name: /VirtualBox/GuestAdd/Components/VBoxControl.exe, value: <varname>version-number</varname>r40720,
    timestamp: 1229098279651731000, flags:
Name: /VirtualBox/GuestAdd/Components/VBoxHook.dll, value: <varname>version-number</varname>r40720,
    timestamp: 1229098279804835000, flags:
Name: /VirtualBox/GuestAdd/Components/VBoxDisp.dll, value: <varname>version-number</varname>r40720,
    timestamp: 1229098279880611000, flags:
Name: /VirtualBox/GuestAdd/Components/VBoxMRXNP.dll, value: <varname>version-number</varname>r40720,
    timestamp: 1229098279882618000, flags:
Name: /VirtualBox/GuestAdd/Components/VBoxService.exe, value: <varname>version-number</varname>r40720,
    timestamp: 1229098279883195000, flags:
Name: /VirtualBox/GuestAdd/Components/VBoxTray.exe, value: <varname>version-number</varname>r40720,
    timestamp: 1229098279885027000, flags:
Name: /VirtualBox/GuestAdd/Components/VBoxGuest.sys, value: <varname>version-number</varname>r40720,
    timestamp: 1229098279886838000, flags:
Name: /VirtualBox/GuestAdd/Components/VBoxMouse.sys, value: <varname>version-number</varname>r40720,
    timestamp: 1229098279890600000, flags:
Name: /VirtualBox/GuestAdd/Components/VBoxSF.sys, value: <varname>version-number</varname>r40720,
    timestamp: 1229098279893056000, flags:
Name: /VirtualBox/GuestAdd/Components/VBoxVideo.sys, value: <varname>version-number</varname>r40720,
    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,
    timestamp: 1229099826300088000, flags:
Name: /VirtualBox/GuestInfo/Net/0/V4/Broadcast, value: 255.255.255.255,
    timestamp: 1229099826300220000, flags:
Name: /VirtualBox/GuestInfo/Net/0/V4/Netmask, value: 255.255.255.0,
    timestamp: 1229099826300350000, flags:
Name: /VirtualBox/GuestInfo/Net/0/Status, value: Up,
    timestamp: 1229099826300524000, flags:
Name: /VirtualBox/GuestInfo/OS/LoggedInUsersList, value: username,
    timestamp: 1229099826317386000, flags:</pre>
    <p>
      To query the value of a single property, use the
      <userinput>get</userinput> subcommand as follows:
    </p>
    <pre xml:space="preserve">$ VBoxManage guestproperty get "Windows Vista III" "/VirtualBox/GuestInfo/OS/Product"
Value: Windows Vista Business Edition</pre>
    <p>
      To add or change guest properties from the guest, use the tool
      <userinput>VBoxControl</userinput>. This tool is included in the Guest
      Additions. When started from a Linux guest, this tool requires
      root privileges for security reasons.
    </p>
    <pre xml:space="preserve">$ sudo VBoxControl guestproperty enumerate
Oracle VirtualBox Guest Additions Command Line Management Interface Version <varname>version-number</varname>
Copyright (C) 2005-2025 Oracle and/or its affiliates

Name: /VirtualBox/GuestInfo/OS/Release, value: 2.6.28-18-generic,
    timestamp: 1265813265835667000, flags: &lt;NULL&gt;
Name: /VirtualBox/GuestInfo/OS/Version, value: #59-Ubuntu SMP Thu Jan 28 01:23:03 UTC 2010,
    timestamp: 1265813265836305000, flags: &lt;NULL&gt;
      ...</pre>
    <p>
      For more complex needs, you can use the <ph conkeyref="vbox-conkeyref-phrases/product-name"/> programming
      interfaces. See <xref href="VirtualBoxAPI.dita"><ph conkeyref="vbox-conkeyref-phrases/product-name"/> Programming Interfaces</xref>.
    </p>
  </body>
</topic>
