# run0

## 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. If not specified
               defaults to "root", unless **--area=** is used (see below), in
               which case this defaults to the invoking user.
    
               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.
    
           **--via-shell**
               Invokes the target user's login shell and runs the specified
               command (if any) via it.
    
               Added in version 258.
    
           **-i**
               Shortcut for **--via-shell --chdir='~'**.
    
               Added in version 258.
    
           **--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** , **--pty-late** , **--pipe**
               Request allocation of a pseudo TTY for the **run0** session (in
               case of **--pty** or **--pty-late**), or request passing the caller's
               STDIO file descriptors directly through (in case of **--pipe**).
               **--pty-late** is very similar to **--pty** but begins the TTY
               processing only once unit startup is complete, leaving input
               to any passwords/polkit agents until that time. If neither
               switch is specified, or if both **--pipe** and one of
               **--pty** /**--pty-late** 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 (in **--pty-late** mode unless **--no-ask-password**
               is specified in which case **--pty** is selected), otherwise the
               relevant file descriptors are passed through directly.
    
               **--pty** and **--pipe** were added in v257.
    
               **--pty-late** was added in v258.
    
           **--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_ environment
               variable pam_systemd(8) respects.
    
               Added in version 258.
    
           **--area=**_AREA_
               Controls the "area" of the target account to log into. Areas
               are secondary home directories within the primary home
               directory of the target user, i.e. logging into area "foobar"
               of an account translates to _$HOME_ being set to ~/Areas/foobar
               on login.
    
               If this option is used, the default user to transition to
               changes from root to the calling user's (but **--user=** takes
               precedence, see above). Or in other words, just specifying an
               area without a user is a mechanism to create a new session of
               the calling user, just with a different area.
    
               This ultimately controls the _$XDG_AREA_ environment variable
               pam_systemd(8) respects.
    
               For details on the area concept see pam_systemd_home(8).
    
               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 through **--via-shell** - when
           specified the target user's shell is used - or **--setenv=SHELL=...**.
           By default, the _originating user's_ shell is executed if operating
           locally, or /bin/sh when operating with **--machine=**.
    
           Note that unlike **sudo** , **run0** always spawns shells with login shell
           semantics, regardless of **-i**.
    


## 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.
    


## 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
    


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