man/run0.xml - main - niceSOFT/systemd

man/run0.xml
467 строк21 KB
Ronan Pigott
run: make custom slice imply XDG_SESSION_CLASS=none
28 июн 2026, 07:48
28 июн 2026, 07:48313e2a3
<?xml version='1.0'?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->

<refentry id="run0"
          xmlns:xi="http://www.w3.org/2001/XInclude">

  <refentryinfo>
    <title>run0</title>
    <productname>systemd</productname>
  </refentryinfo>

  <refmeta>
    <refentrytitle>run0</refentrytitle>
    <manvolnum>1</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>run0</refname>
    <refpurpose>Elevate privileges</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <cmdsynopsis>
      <command>run0</command>
      <arg choice="opt" rep="repeat">OPTIONS</arg>
      <arg choice="opt" rep="repeat">COMMAND</arg>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para><command>run0</command> may be used to temporarily and interactively acquire elevated or different
    privileges. It serves a similar purpose as <citerefentry
    project='man-pages'><refentrytitle>sudo</refentrytitle><manvolnum>8</manvolnum></citerefentry>, but
    operates differently in a couple of key areas:</para>

    <itemizedlist>
      <listitem><para>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.
      </para></listitem>

      <listitem><para>Authentication takes place via <ulink
      url="https://www.freedesktop.org/wiki/Software/polkit">polkit</ulink>, thus isolating the
      authentication prompt from the terminal (if possible).</para></listitem>

      <listitem><para>An independent pseudo-tty is allocated for the invoked command, detaching its lifecycle and
      isolating it for security.</para></listitem>

      <listitem><para>No SetUID/SetGID file access bit functionality is used for the implementation.</para></listitem>
    </itemizedlist>

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

    <para>Any session invoked via <command>run0</command> will run through the
    <literal>systemd-run0</literal> PAM stack.</para>

    <para>Note that <command>run0</command> is implemented as an alternative multi-call invocation of
    <citerefentry><refentrytitle>systemd-run</refentrytitle><manvolnum>1</manvolnum></citerefentry>. That is,
    <command>run0</command> is a symbolic link to <command>systemd-run</command> executable file, and it
    behaves as <command>run0</command> if it is invoked through the symbolic link, otherwise behaves as
    <command>systemd-run</command>.</para>
  </refsect1>

  <refsect1>
    <title>Options</title>

    <para>The following options are understood:</para>

    <variablelist>
      <varlistentry>
        <term><option>--unit=</option></term>

        <listitem><para>Use this unit name instead of an automatically generated one.</para>

        <xi:include href="version-info.xml" xpointer="v256"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--property=</option></term>

        <listitem><para>Sets a property of the service unit that is created. This option takes an assignment
        in the same format as
        <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
        <command>set-property</command> command.</para>

        <xi:include href="version-info.xml" xpointer="v256"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--description=</option></term>

        <listitem><para>Provide a description for the service unit that is invoked. If not specified,
        the command itself will be used as a description. See <varname>Description=</varname> in
        <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
        </para>

        <xi:include href="version-info.xml" xpointer="v256"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--slice=</option></term>

        <listitem><para>Make the new <filename>.service</filename> unit part of the specified slice, instead
        of <filename>user.slice</filename>. This option conflicts with <option>--lightweight=</option> and
        <option>--area=</option>, and implies <literal>XDG_SESSION_CLASS=none</literal>,
        to keep the new process within the specified slice instead of a new session scope.</para>

        <xi:include href="version-info.xml" xpointer="v256"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--slice-inherit</option></term>

        <listitem><para>Make the new <filename>.service</filename> unit part of the slice the
        <command>run0</command> itself has been invoked in. This option may be combined with
        <option>--slice=</option>, in which case the slice specified via <option>--slice=</option> is placed
        within the slice the <command>run0</command> command is invoked in. Also conflicts with
        <option>--lightweight=</option> and <option>--area=</option> and implies
        <literal>XDG_SESSION_CLASS=none</literal>, similar to <option>--slice=</option>.</para>

        <para>Example: consider <command>run0</command> being invoked in the slice
        <filename>foo.slice</filename>, and the <option>--slice=</option> argument is
        <filename>bar</filename>. The unit will then be placed under
        <filename>foo-bar.slice</filename>.</para>

        <xi:include href="version-info.xml" xpointer="v256"/>

        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--user=</option></term>
        <term><option>-u</option></term>
        <term><option>--group=</option></term>
        <term><option>-g</option></term>

        <listitem><para>Switches to the specified user/group. If not specified defaults to
        <literal>root</literal>, unless <option>--area=</option> or <option>--empower</option> are used (see
        below), in which case this defaults to the invoking user.</para>

        <xi:include href="version-info.xml" xpointer="v256"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--nice=</option></term>

        <listitem><para>Runs the invoked session with the specified nice level.</para>

        <xi:include href="version-info.xml" xpointer="v256"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--chdir=</option></term>
        <term><option>-D</option></term>

        <listitem><para>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.</para>

        <xi:include href="version-info.xml" xpointer="v256"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-k</option></term>
        <term><option>--reset-timestamp</option></term>

        <listitem><para>Revokes temporary polkit authorization for this terminal, if present.</para>

        <xi:include href="version-info.xml" xpointer="v262"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-K</option></term>
        <term><option>--remove-timestamp</option></term>

        <listitem><para>Revokes all temporary polkit authorizations for this user session.</para>

        <xi:include href="version-info.xml" xpointer="v262"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-v</option></term>
        <term><option>--validate</option></term>

        <listitem><para>Request authorization from polkit. Can be used to create a temporary authorization
        without running a command.</para>

        <xi:include href="version-info.xml" xpointer="v262"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--via-shell</option></term>

        <listitem><para>Invokes the target user's login shell and runs the specified command (if any) via it.</para>

        <xi:include href="version-info.xml" xpointer="v258"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-i</option></term>

        <listitem><para>Shortcut for <option>--via-shell --chdir='~'</option>.</para>

        <xi:include href="version-info.xml" xpointer="v258"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--setenv=<replaceable>NAME</replaceable>[=<replaceable>VALUE</replaceable>]</option></term>

        <listitem><para>Runs the invoked session with the specified environment variable set. This parameter
        may be used more than once to set multiple variables. When <literal>=</literal> and
        <replaceable>VALUE</replaceable> are omitted, the value of the variable with the same name in the
        invoking environment will be used.</para>

        <xi:include href="version-info.xml" xpointer="v256"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--background=<replaceable>COLOR</replaceable></option></term>

        <listitem><para>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
        <literal>40</literal>, <literal>41</literal>, …, <literal>47</literal>, <literal>48;2;…</literal>,
        <literal>48;5;…</literal>. See <ulink
        url="https://en.wikipedia.org/wiki/ANSI_escape_code#SGR_(Select_Graphic_Rendition)_parameters">ANSI
        Escape Code (Wikipedia)</ulink> for details. Set to an empty string to disable.</para>

        <para>Example: <literal>--background=44</literal> for a blue background.</para>

        <xi:include href="version-info.xml" xpointer="v256"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--pty</option></term>
        <term><option>--pty-late</option></term>
        <term><option>--pipe</option></term>

        <listitem><para>Request allocation of a pseudo TTY for the <command>run0</command> session (in case
        of <option>--pty</option> or <option>--pty-late</option>), or request passing the caller's STDIO file
        descriptors directly through (in case of <option>--pipe</option>). <option>--pty-late</option> is
        very similar to <option>--pty</option> 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 <option>--pipe</option> and one of
        <option>--pty</option>/<option>--pty-late</option> 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 <option>--pty-late</option> mode unless
        <option>--no-ask-password</option> is specified in which case <option>--pty</option> is selected),
        otherwise the relevant file descriptors are passed through directly.</para>

        <para id="v257"><option>--pty</option> and <option>--pipe</option> were added in v257.</para>
        <para id="v258"><option>--pty-late</option> was added in v258.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--shell-prompt-prefix=<replaceable>STRING</replaceable></option></term>

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

        <xi:include href="version-info.xml" xpointer="v257"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--lightweight=<replaceable>BOOLEAN</replaceable></option></term>

        <listitem><para>Controls whether to activate the per-user service manager for the target user. By
        default (unset or set to <option>auto</option>), if the target user is <literal>root</literal> or
        a system user the per-user service manager is not activated as effect of the <command>run0</command>
        invocation, otherwise it is.</para>

        <para>This ultimately controls the <varname>$XDG_SESSION_CLASS</varname> environment variable
        <citerefentry><refentrytitle>pam_systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
        respects.</para>

        <xi:include href="version-info.xml" xpointer="v258"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--area=<replaceable>AREA</replaceable></option></term>

        <listitem><para>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
        <literal>foobar</literal> of an account translates to <varname>$HOME</varname> being set to
        <filename>~/Areas/foobar</filename> on login.</para>

        <para>If this option is used, the default user to transition to changes from root to the calling
        user's (but <option>--user=</option> 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.</para>

        <para>This ultimately controls the <varname>$XDG_AREA</varname> environment variable
        <citerefentry><refentrytitle>pam_systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
        respects.</para>

        <para>For details on the area concept see
        <citerefentry><refentrytitle>pam_systemd_home</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>

        <xi:include href="version-info.xml" xpointer="v258"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--empower</option></term>

        <listitem><para>If specified, run0 will elevate the privileges of the selected user (using
        <option>--user=</option>) or the current user if no user is explicitly selected. Currently this means
        we give the invoked process all available capabilities and add the <literal>empower</literal>
        group as a supplemental group (for which all polkit actions are allowed by default), but other
        privileges may be granted in the future as well when using this option.</para>

        <para>Note that other (unprivileged) processes of the selected user will have privileges over the
        invoked process. Consider not using this option in an environment where there might be malicious
        processes running as the selected user.</para>

        <xi:include href="version-info.xml" xpointer="v259"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--same-root-dir</option></term>

        <listitem><para>Execute the <command>run0</command> session in the same root directory that the
        <command>run0</command> command is executed in.</para>

        <xi:include href="version-info.xml" xpointer="v259"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><option>--machine=</option></term>

        <listitem>
          <para>Execute operation in a local container. Specify a container name to connect to.</para>

          <xi:include href="version-info.xml" xpointer="v256"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><option>-n</option></term>
        <term><option>--non-interactive</option></term>

        <listitem><para>Equivalent to <option>--no-ask-password</option>.</para>

        <xi:include href="version-info.xml" xpointer="v262"/></listitem>
      </varlistentry>

      <xi:include href="standard-options.xml" xpointer="no-ask-password" />
      <xi:include href="standard-options.xml" xpointer="help" />
      <xi:include href="standard-options.xml" xpointer="version" />
    </variablelist>

    <para>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 <option>--via-shell</option> - when specified the target user's shell
    is used - or <option>--setenv=SHELL=…</option>. By default, the <emphasis>originating user's</emphasis> shell
    is executed if operating locally, or <filename>/bin/sh</filename> when operating with <option>--machine=</option>.</para>

    <para>Note that unlike <command>sudo</command>, <command>run0</command> always spawns shells with login shell
    semantics, regardless of <option>-i</option>.</para>
  </refsect1>

  <refsect1>
    <title>Exit status</title>

    <para>On success, 0 is returned. If <command>run0</command> failed to start the session or the specified command fails, a
    non-zero return value will be returned.</para>
  </refsect1>

  <refsect1>
    <title>Environment Variables</title>

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

    <variablelist>
      <varlistentry>
        <term><varname>$TERM</varname></term>
        <listitem><para>Copied from the <varname>$TERM</varname> of the caller. Can be overridden with
        <option>--setenv=</option></para>

        <xi:include href="version-info.xml" xpointer="v256"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>$SUDO_USER</varname></term>
        <listitem><para>Set to the username of the originating user.</para>

        <xi:include href="version-info.xml" xpointer="v256"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>$SUDO_UID</varname></term>
        <listitem><para>Set to the numeric UNIX user id of the originating user.</para>

        <xi:include href="version-info.xml" xpointer="v256"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>$SUDO_GID</varname></term>
        <listitem><para>Set to the primary numeric UNIX group id of the originating session.</para>

        <xi:include href="version-info.xml" xpointer="v256"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>$SHELL_PROMPT_PREFIX</varname></term>
        <listitem><para>By default, set to the superhero emoji (if supported), but may be overridden with the
        <varname>$SYSTEMD_RUN_SHELL_PROMPT_PREFIX</varname> environment variable (see below), or the
        <option>--shell-prompt-prefix=</option> switch (see above).</para>

        <xi:include href="version-info.xml" xpointer="v257"/></listitem>
      </varlistentry>
    </variablelist>

    <para>The following variables may be passed to <command>run0</command>:</para>

    <variablelist>
      <varlistentry>
        <term><varname>$SYSTEMD_RUN_SHELL_PROMPT_PREFIX</varname></term>
        <listitem><para>If set, overrides the default shell prompt prefix that <command>run0</command> sets
        for the invoked shell (the superhero emoji). Set to an empty string to disable shell prompt
        prefixing.</para>

        <xi:include href="version-info.xml" xpointer="v257"/></listitem>
      </varlistentry>
    </variablelist>

  </refsect1>

  <refsect1>
    <title>See Also</title>
    <para><simplelist type="inline">
      <member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
      <member><citerefentry><refentrytitle>systemd-run</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
      <member><citerefentry project='man-pages'><refentrytitle>sudo</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
      <member><citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
      <member><citerefentry><refentrytitle>pam_systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry></member>
    </simplelist></para>
  </refsect1>

</refentry>