run0(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXIT STATUS | ENVIRONMENT VARIABLES | SEE ALSO | NOTES | COLOPHON

RUN0(1)                            run0                           RUN0(1)

NAME         top

       run0 - Elevate privileges

SYNOPSIS         top


       run0 [OPTIONS...] [COMMAND...]

DESCRIPTION         top

       run0 may be used to temporarily and interactively acquire elevated
       or different privileges. It serves a similar purpose as sudo(8),
       but operates differently in a couple of key areas:

       •   No execution or security context credentials are inherited
           from the caller into the invoked commands, as they are invoked
           from a fresh, isolated service forked off by the service
           manager.

       •   Authentication takes place via polkit[1], thus isolating the
           authentication prompt from the terminal (if possible).

       •   An independent pseudo-tty is allocated for the invoked
           command, detaching its lifecycle and isolating it for
           security.

       •   No SetUID/SetGID file access bit functionality is used for the
           implementation.

       Altogether this should provide a safer and more robust alternative
       to the sudo mechanism, in particular in OS environments where
       SetUID/SetGID support is not available (for example by setting the
       NoNewPrivileges= variable in systemd-system.conf(5)).

       Any session invoked via run0 will run through the "systemd-run0"
       PAM stack.

       Note that run0 is implemented as an alternative multi-call
       invocation of systemd-run(1). That is, run0 is a symbolic link to
       systemd-run executable file, and it behaves as run0 if it is
       invoked through the symbolic link, otherwise behaves as
       systemd-run.

OPTIONS         top

       The following options are understood:

       --unit=
           Use this unit name instead of an automatically generated one.

           Added in version 256.

       --property=
           Sets a property of the service unit that is created. This
           option takes an assignment in the same format as
           systemctl(1)'s set-property command.

           Added in version 256.

       --description=
           Provide a description for the service unit that is invoked. If
           not specified, the command itself will be used as a
           description. See Description= in systemd.unit(5).

           Added in version 256.

       --slice=
           Make the new .service unit part of the specified slice,
           instead of user.slice.

           Added in version 256.

       --slice-inherit
           Make the new .service unit part of the slice the run0 itself
           has been invoked in. This option may be combined with
           --slice=, in which case the slice specified via --slice= is
           placed within the slice the run0 command is invoked in.

           Example: consider run0 being invoked in the slice foo.slice,
           and the --slice= argument is bar. The unit will then be placed
           under foo-bar.slice.

           Added in version 256.

       --user=, -u, --group=, -g
           Switches to the specified user/group instead of root.

           Added in version 256.

       --nice=
           Runs the invoked session with the specified nice level.

           Added in version 256.

       --chdir=, -D
           Runs the invoked session with the specified working directory.
           If not specified defaults to the client's current working
           directory if switching to the root user, or the target user's
           home directory otherwise.

           Added in version 256.

       --setenv=NAME[=VALUE]
           Runs the invoked session with the specified environment
           variable set. This parameter may be used more than once to set
           multiple variables. When "=" and VALUE are omitted, the value
           of the variable with the same name in the invoking environment
           will be used.

           Added in version 256.

       --background=COLOR
           Change the terminal background color to the specified ANSI
           color as long as the session lasts. If not specified, the
           background will be tinted in a reddish tone when operating as
           root, and in a yellowish tone when operating under another
           UID, as reminder of the changed privileges. The color
           specified should be an ANSI X3.64 SGR background color, i.e.
           strings such as "40", "41", ..., "47", "48;2;...", "48;5;...".
           See ANSI Escape Code (Wikipedia)[2] for details. Set to an
           empty string to disable.

           Example: "--background=44" for a blue background.

           Added in version 256.

       --pty, --pipe
           Request allocation of a pseudo TTY for the run0 session (in
           case of --pty), or request passing the caller's STDIO file
           descriptors directly through (in case of --pipe). If neither
           switch is specified, or if both switches are specified, the
           mode will be picked automatically: if standard input, standard
           output and standard error output are all connected to a TTY
           then a pseudo TTY is allocated, otherwise the relevant file
           descriptors are passed through directly.

           Added in version 257.

       --shell-prompt-prefix=STRING
           Set a shell prompt prefix string. This ultimately controls the
           $SHELL_PROMPT_PREFIX environment variable for the invoked
           program, which is typically imported into the shell prompt. By
           default – if emojis are supported –, a superhero emoji is
           shown (🦸). This default may also be changed (or turned off)
           by passing the $SYSTEMD_RUN_SHELL_PROMPT_PREFIX environment
           variable to run0, see below. Set to an empty string to disable
           shell prompt prefixing.

           Added in version 257.

       --lightweight=BOOLEAN
           Controls whether to activate the per-user service manager for
           the target user. By default if the target user is "root" or a
           system user the per-user service manager is not activated as
           effect of the run0 invocation, otherwise it is.

           This ultimately controls the $XDG_SESSION_CLASS variable
           pam_systemd(8) respects.

           Added in version 258.

       --machine=
           Execute operation in a local container. Specify a container
           name to connect to.

           Added in version 256.

       --no-ask-password
           Do not query the user for authentication for privileged
           operations.

       -h, --help
           Print a short help text and exit.

       --version
           Print a short version string and exit.

       All command line arguments after the first non-option argument
       become part of the command line of the launched process. If no
       command line is specified an interactive shell is invoked. The
       shell to invoke may be controlled via --setenv=SHELL=...  and
       currently defaults to the originating user's shell (i.e. not the
       target user's!) if operating locally, or /bin/sh when operating
       with --machine=.

EXIT STATUS         top

       On success, 0 is returned. If run0 failed to start the session or
       the specified command fails, a non-zero return value will be
       returned.

ENVIRONMENT VARIABLES         top

       As with systemd-run, the session will inherit the system
       environment from the service manager. In addition, the following
       environment variables will be set:

       $TERM
           Copied from the $TERM of the caller. Can be overridden with
           --setenv=

           Added in version 256.

       $SUDO_USER
           Set to the username of the originating user.

           Added in version 256.

       $SUDO_UID
           Set to the numeric UNIX user id of the originating user.

           Added in version 256.

       $SUDO_GID
           Set to the primary numeric UNIX group id of the originating
           session.

           Added in version 256.

       $SHELL_PROMPT_PREFIX
           By default, set to the superhero emoji (if supported), but may
           be overridden with the $SYSTEMD_RUN_SHELL_PROMPT_PREFIX
           environment variable (see below), or the
           --shell-prompt-prefix= switch (see above).

           Added in version 257.

       The following variables may be passed to run0:

       $SYSTEMD_RUN_SHELL_PROMPT_PREFIX
           If set, overrides the default shell prompt prefix that run0
           sets for the invoked shell (the superhero emoji). Set to an
           empty string to disable shell prompt prefixing.

           Added in version 257.

SEE ALSO         top

       systemd(1), systemd-run(1), sudo(8), machinectl(1), pam_systemd(8)

NOTES         top

        1. polkit
           https://www.freedesktop.org/wiki/Software/polkit

        2. ANSI Escape Code (Wikipedia)
           https://en.wikipedia.org/wiki/ANSI_escape_code#SGR_(Select_Graphic_Rendition)_parameters

COLOPHON         top

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systemd 258~devel                                                 RUN0(1)

Pages that refer to this page: systemd-ask-password(1)systemd-run(1)systemd.directives(7)systemd.index(7)