man: deemphasize "halt"

Systemd documents "halt" as the primary shutdown mechanism, redirecting
"reboot" and "shutdown" to the halt(8), but halt is a really strange and
obsolete concept. Who would want to really keep their machine running after
shutdown? I expect that halting is almost unused. Let's at least make it less
prominent in the docs.

While at it, use "power off" for a verb and "power-off" for noun (but "poweroff"
of the actual command name).

1 files changed, 158 insertions, 0 deletions

diff --git a/man/poweroff.xml b/man/poweroff.xml
new file mode 100644
index 0000000000..2841dc7769
--- /dev/null
+++ b/man/poweroff.xml
@@ -0,0 +1,158 @@
+<?xml version='1.0'?> <!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
+  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
+
+<refentry id="poweroff"
+    xmlns:xi="http://www.w3.org/2001/XInclude">
+
+  <refentryinfo>
+    <title>poweroff</title>
+    <productname>systemd</productname>
+  </refentryinfo>
+
+  <refmeta>
+    <refentrytitle>poweroff</refentrytitle>
+    <manvolnum>8</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>poweroff</refname>
+    <refname>reboot</refname>
+    <refname>halt</refname>
+    <refpurpose>Power off, reboot, or halt the machine</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <cmdsynopsis>
+      <command>poweroff</command>
+      <arg choice="opt" rep="repeat">OPTIONS</arg>
+    </cmdsynopsis>
+    <cmdsynopsis>
+      <command>reboot</command>
+      <arg choice="opt" rep="repeat">OPTIONS</arg>
+    </cmdsynopsis>
+    <cmdsynopsis>
+      <command>halt</command>
+      <arg choice="opt" rep="repeat">OPTIONS</arg>
+    </cmdsynopsis>
+  </refsynopsisdiv>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para><command>poweroff</command>, <command>reboot</command>, and <command>halt</command> may be used to
+    power off, reboot, or halt the machine. All three commands take the same options.</para>
+
+  </refsect1>
+
+  <refsect1>
+    <title>Options</title>
+
+    <para>The following options are understood:</para>
+
+    <variablelist>
+      <varlistentry>
+        <term><option>--help</option></term>
+
+        <xi:include href="standard-options.xml" xpointer="help-text" />
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--halt</option></term>
+
+        <listitem><para>Halt the machine, regardless of which one of
+        the three commands is invoked.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-p</option></term>
+        <term><option>--poweroff</option></term>
+
+        <listitem><para>Power off the machine, when either <command>halt</command>
+        or <command>poweroff</command> is invoked. This option is ignored when
+        <command>reboot</command> is invoked.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--reboot</option></term>
+
+        <listitem><para>Reboot the machine, regardless of which one of
+        the three commands is invoked.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-f</option></term>
+        <term><option>--force</option></term>
+
+        <listitem>
+          <para>Force immediate power-off, halt, or reboot. If specified, the command does not contact the
+          init system. In most cases, filesystems are not properly unmounted before shutdown. For example,
+          the command <command>reboot -f</command> is mostly equivalent to
+          <command>systemctl reboot -ff</command>, instead of <command>systemctl reboot -f</command>.
+          </para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-w</option></term>
+        <term><option>--wtmp-only</option></term>
+
+        <listitem><para>Only write wtmp shutdown entry, do not actually power off, reboot, or halt.
+        </para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-d</option></term>
+        <term><option>--no-wtmp</option></term>
+
+        <listitem><para>Do not write wtmp shutdown entry.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>-n</option></term>
+        <term><option>--no-sync</option></term>
+
+        <listitem><para>Don't sync hard disks/storage media before power-off, reboot, or halt.
+        </para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><option>--no-wall</option></term>
+
+        <listitem><para>Do not send wall message before power-off, reboot, or halt.</para></listitem>
+      </varlistentry>
+    </variablelist>
+  </refsect1>
+
+  <refsect1>
+    <title>Exit status</title>
+
+    <para>On success, 0 is returned, a non-zero failure code otherwise.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>Notes</title>
+
+    <para>These commands are implemented in a way that preserves basic compatibility with the original SysV
+    commands. <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+    verbs <command>poweroff</command>, <command>reboot</command>, <command>halt</command> provide the same
+    functionality with some additional features.</para>
+
+    <para>Note that on many SysV systems <command>halt</command> used to be synonymous to
+    <command>poweroff</command>, i.e. both commands would equally result in powering the machine off. systemd
+    is more accurate here, and <command>halt</command> results in halting the machine only (leaving power
+    on), and <command>poweroff</command> is required to actually power it off.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>See Also</title>
+    <para>
+      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>shutdown</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+      <citerefentry project='man-pages'><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+    </para>
+  </refsect1>
+
+</refentry>