man: fix incorrectly placed full stop

[thirdparty/systemd.git] / man / daemon.xml

diff --git a/man/daemon.xml b/man/daemon.xml
index 7724bb4e08d8efa25008bd9d0cd051b010c9f339..072529eeecbce9422e0a95c907c3dcf094020b57 100644 (file)
--- a/man/daemon.xml
+++ b/man/daemon.xml
@@ -1,10 +1,7 @@
 <?xml version='1.0'?> <!--*-nxml-*-->
-<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+<!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+
--->
+<!-- SPDX-License-Identifier: LGPL-2.1+ -->
 
 <refentry id="daemon">
 
@@ -77,9 +74,10 @@
         <function>setsid()</function> to detach from any terminal and
         create an independent session.</para></listitem>
 
-        <listitem><para>In the child, call <function>fork()</function>
-        again, to ensure that the daemon can never re-acquire a
-        terminal again.</para></listitem>
+        <listitem><para>In the child, call <function>fork()</function> again, to ensure that the daemon can
+        never re-acquire a terminal again. (This relevant if the program — and all its dependencies — does
+        not carefully specify `O_NOCTTY` on each and every single `open()` call that might potentially open a
+        TTY device node.)</para></listitem>
 
         <listitem><para>Call <function>exit()</function> in the first
         child, so that only the second child (the actual daemon
@@ -104,7 +102,7 @@
 
         <listitem><para>In the daemon process, write the daemon PID
         (as returned by <function>getpid()</function>) to a PID file,
-        for example <filename>/run/foobar.pid</filename> (for a
+        for example <filename index='false'>/run/foobar.pid</filename> (for a
         hypothetical daemon "foobar") to ensure that the daemon cannot
         be started more than once. This must be implemented in
         race-free fashion so that the PID file is only updated when it
@@ -244,6 +242,10 @@
         and
         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem>
 
+        <listitem><para>As new-style daemons are invoked without a controlling TTY (but as their own session
+        leaders) care should be taken to always specify `O_NOCTTY` on `open()` calls that possibly reference
+        a TTY device node, so that no controlling TTY is accidentally acquired.</para></listitem>
+
       </orderedlist>
 
       <para>These recommendations are similar but not identical to the
@@ -355,7 +357,7 @@
       special target unit <filename>sockets.target</filename>. It is
       recommended to place a
       <varname>WantedBy=sockets.target</varname> directive in the
-      <literal>[Install]</literal> section to automatically add such a
+      [Install] section to automatically add such a
       dependency on installation of a socket unit. Unless
       <varname>DefaultDependencies=no</varname> is set, the necessary
       ordering dependencies are implicitly created for all socket
@@ -518,7 +520,7 @@
         operating system-independent.</para></listitem>
 
         <listitem><para>Make sure to include an
-        <literal>[Install]</literal> section including installation
+        [Install] section including installation
         information for the unit file. See
         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
         for details. To activate your service on boot, make sure to