dbus-update-activation-environment man page

dbus-update-activation-environment — update environment used for D-Bus session services


dbus-update-activation-environment [--systemd] [--verbose] --all | VAR... | VAR=VAL...


dbus-update-activation-environment updates the list of environment variables used by dbus-daemon --session when it activates session services without using systemd.

With the --systemd option, if an instance of systemd --user is available on D-Bus, it also updates the list of environment variables used by systemd --user when it activates user services, including D-Bus session services for which dbus-daemon has been configured to delegate activation to systemd. This is very similar to the import-environment command provided by systemctl(1)).

Variables that are special to dbus-daemon or systemd may be set, but their values will be overridden when a service is started. For instance, it is not useful to add DBUS_SESSION_BUS_ADDRESS to dbus-daemon's activation environment, although it might still be useful to add it to systemd's activation environment.



Set all environment variables present in the environment used by dbus-update-activation-environment.


Set environment variables for systemd user services as well as for traditional D-Bus session services.


Output messages to standard error explaining what dbus-update-activation-environment is doing.


If VAR is present in the environment of dbus-update-activation-environment, set it to the same value for D-Bus services. Its value must be UTF-8 (if not, it is skipped with a warning). If VAR is not present in the environment, this argument is silently ignored.


Set VAR to VAL, which must be UTF-8.


dbus-update-activation-environment is primarily designed to be used in Linux distributions' X11 session startup scripts, in conjunction with the "user bus" design.

To propagate DISPLAY and XAUTHORITY to dbus-daemon and, if present, systemd, and propagate DBUS_SESSION_BUS_ADDRESS to systemd:

        dbus-update-activation-environment --systemd \

To propagate all environment variables except XDG_SEAT, XDG_SESSION_ID and XDG_VTNR to dbus-daemon (and, if present, systemd) for compatibility with legacy X11 session startup scripts:

        # in a subshell so the variables remain set in the
        # parent script
          unset XDG_SEAT
          unset XDG_SESSION_ID
          unset XDG_VTNR

          dbus-update-activation-environment --systemd --all

Exit Status

dbus-update-activation-environment exits with status 0 on success, EX_USAGE (64) on invalid command-line options, EX_OSERR (71) if unable to connect to the session bus, or EX_UNAVAILABLE (69) if unable to set the environment variables. Other nonzero exit codes might be added in future versions.


DBUS_SESSION_BUS_ADDRESS, XDG_RUNTIME_DIR and/or DISPLAY are used to find the address of the session bus.


dbus-daemon does not provide a way to unset environment variables after they have been set (although systemd does), so dbus-update-activation-environment does not offer this functionality either.

POSIX does not specify the encoding of non-ASCII environment variable names or values and allows them to contain any non-zero byte, but neither dbus-daemon nor systemd supports environment variables with non-UTF-8 names or values. Accordingly, dbus-update-activation-environment assumes that any name or value that appears to be valid UTF-8 is intended to be UTF-8, and ignores other names or values with a warning.


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

See Also

dbus-daemon(1), systemd(1), the import-environment command of systemctl(1)


04/07/2017 D-Bus 1.11.12 User Commands