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)