Provided by: systemd_257.2-3ubuntu1_amd64 
NAME
run0 - Elevate privileges
SYNOPSIS
run0 [OPTIONS...] [COMMAND...]
DESCRIPTION
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
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.
--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
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
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
systemd(1), systemd-run(1), sudo(8), machinectl(1)
NOTES
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