NAME

       dbus-uuidgen - Utility to generate UUIDs

SYNOPSIS

       dbus-uuidgen [--version] [--ensure[=FILENAME]] [--get[=FILENAME]]

DESCRIPTION

       The dbus-uuidgen command generates or reads a universally unique ID.

       Note that the D-Bus UUID has no relationship to RFC 4122 and does not generate UUIDs compatible with that
       spec. Many systems have a separate command for that (often called "uuidgen").

       See http://www.freedesktop.org/software/dbus/ for more information about D-Bus.

       The primary usage of dbus-uuidgen is to run in the post-install script of a D-Bus package like this:
         dbus-uuidgen --ensure

       This  will  ensure  that  /var/lib/dbus/machine-id  exists and has the uuid in it.  It won't overwrite an
       existing uuid, since this id should remain fixed for a single machine until the next reboot at least.

       The important properties of the machine UUID are that 1) it remains unchanged until the next  reboot  and
       2) it is different for any two running instances of the OS kernel. That is, if two processes see the same
       UUID,   they   should  also  see  the  same  shared  memory,  UNIX  domain  sockets,  local  X  displays,
       localhost.localdomain resolution, process IDs, and so forth.

       If you run dbus-uuidgen with no options it just prints a new uuid made up out of thin air.

       If you run it with --get, it prints the machine UUID by default, or the UUID in the specified file if you
       specify a file.

       If you try to change an existing machine-id on a running system, it will probably result  in  bad  things
       happening. Don't try to change this file. Also, don't make it the same on two different systems; it needs
       to be different anytime there are two different kernels running.

       The UUID should be different on two different virtual machines, because there are two different kernels.

OPTIONS

       The following options are supported:

       --get[=FILENAME]
              If  a  filename  is  not  given,  defaults  to localstatedir/lib/dbus/machine-id (localstatedir is
              usually /var). If this file exists and is valid, the uuid  in  the  file  is  printed  on  stdout.
              Otherwise, the command exits with a nonzero status.

       --ensure[=FILENAME]
              If  a  filename  is  not  given,  defaults  to localstatedir/lib/dbus/machine-id (localstatedir is
              usually /var). If this file exists then it will be validated, and a failure code  returned  if  it
              contains  the  wrong thing.  If the file does not exist, it will be created with a new uuid in it.
              On success, prints no output.

       --version
              Print the version of dbus-uuidgen

AUTHOR

       See http://www.freedesktop.org/software/dbus/doc/AUTHORS

BUGS

       Please    send    bug    reports    to    the    D-Bus    mailing    list    or    bug    tracker,    see
       http://www.freedesktop.org/software/dbus/

                                                                                                 dbus-uuidgen(1)