man: document sd-daemon.[ch]

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diff --git a/man/sd-daemon.xml b/man/sd-daemon.xml
new file mode 100644
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--- /dev/null
+++ b/man/sd-daemon.xml
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+<?xml version='1.0'?> <!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+        "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+
+<!--
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+-->
+
+<refentry id="sd-daemon">
+
+        <refentryinfo>
+                <title>sd-daemon</title>
+                <productname>systemd</productname>
+
+                <authorgroup>
+                        <author>
+                                <contrib>Developer</contrib>
+                                <firstname>Lennart</firstname>
+                                <surname>Poettering</surname>
+                                <email>lennart@poettering.net</email>
+                        </author>
+                </authorgroup>
+        </refentryinfo>
+
+        <refmeta>
+                <refentrytitle>sd-daemon</refentrytitle>
+                <manvolnum>7</manvolnum>
+        </refmeta>
+
+        <refnamediv>
+                <refname>sd-daemon</refname>
+                <refpurpose>Reference implementation of APIs for
+                new-style daemons</refpurpose>
+        </refnamediv>
+
+        <refsynopsisdiv>
+                <funcsynopsis>
+                        <funcsynopsisinfo>#include "sd-daemon.h"</funcsynopsisinfo>
+                </funcsynopsis>
+        </refsynopsisdiv>
+
+        <refsect1>
+                <title>Description</title>
+
+                <para><filename>sd-daemon.c</filename> and
+                <filename>sd-daemon.h</filename> provide a reference
+                implementation of various APIs for new-style daemons,
+                as implemented by the
+                <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+                init system.</para>
+
+                <para>See
+                <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>sd_booted</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>sd_is_fifo</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+                for more information about the functions
+                implemented. In addition to these functions a couple
+                of logging prefixes are defined as macros:</para>
+
+                <programlisting>#define SD_EMERG   "&lt;0&gt;"  /* system is unusable */
+#define SD_ALERT   "&lt;1&gt;"  /* action must be taken immediately */
+#define SD_CRIT    "&lt;2&gt;"  /* critical conditions */
+#define SD_ERR     "&lt;3&gt;"  /* error conditions */
+#define SD_WARNING "&lt;4&gt;"  /* warning conditions */
+#define SD_NOTICE  "&lt;5&gt;"  /* normal but significant condition */
+#define SD_INFO    "&lt;6&gt;"  /* informational */
+#define SD_DEBUG   "&lt;7&gt;"  /* debug-level messages */</programlisting>
+
+                <para>These prefixes are intended to be used in
+                conjunction with STDERR-based logging as implemented
+                by systemd. If a systemd service definition file is
+                configured with <varname>StandardError=syslog</varname>
+                or <varname>StandardError=kmsg</varname> these
+                prefixes can be used to encode a log level in lines
+                printed. This is similar to the kernel
+                <function>printk()</function>-style logging. See
+                <citerefentry><refentrytitle>klogctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+                for more information.</para>
+
+                <para>The log levels are identical to
+                <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>'s
+                log level system. To use these prefixes simply prefix
+                every line with one of these strings. A line that is
+                not prefixed will be logged at the default log level
+                SD_INFO.</para>
+
+                <example>
+                        <title>Hello World</title>
+
+                        <para>A daemon may log with the log level
+                        NOTICE by issuing this call:</para>
+
+                        <programlisting>fprintf(stderr, SD_NOTICE "Hello World!\n");</programlisting>
+                </example>
+        </refsect1>
+
+        <refsect1>
+                <title>Notes</title>
+
+                <para>These interfaces are provided by the reference
+                implementation of APIs for new-style daemons and
+                distributed with the systemd package. The algorithms
+                they implement are simple, and can easily be
+                reimplemented in daemons if it is important to support
+                this interface without using the reference
+                implementation. See the respective function man pages
+                for details.</para>
+
+                <para>In addition, for details about the algorithms
+                check the liberally licensed reference implementation
+                sources:
+                <ulink url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.c"/>
+                resp. <ulink url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.h"/></para>
+
+                <para>These APIs are implemented in the reference
+                implementation's drop-in
+                <filename>sd-daemon.c</filename> and
+                <filename>sd-daemon.h</filename> files. It is
+                recommended that applications consuming these APIs copy
+                the implementation into their source tree, either
+                verbatim or in excerpts. These interfaces are
+                currently not available in a dynamic library.</para>
+
+                <para>The functions directly related to new-style
+                daemons become NOPs when -DDISABLE_SYSTEMD is set
+                during compilation. In addition, if
+                <filename>sd-daemon.c</filename> is compiled on
+                non-Linux systems they become NOPs, too.</para>
+        </refsect1>
+
+        <refsect1>
+                <title>See Also</title>
+                <para>
+                        <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>sd_booted</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>sd_is_fifo</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>fprintf</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+                </para>
+        </refsect1>
+
+</refentry>
diff --git a/man/sd_booted.xml b/man/sd_booted.xml
new file mode 100644
index 0000000000..6129a777c2
--- /dev/null
+++ b/man/sd_booted.xml
@@ -0,0 +1,122 @@
+<?xml version='1.0'?> <!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+        "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+
+<!--
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+-->
+
+<refentry id="sd_booted">
+
+        <refentryinfo>
+                <title>sd_booted</title>
+                <productname>systemd</productname>
+
+                <authorgroup>
+                        <author>
+                                <contrib>Developer</contrib>
+                                <firstname>Lennart</firstname>
+                                <surname>Poettering</surname>
+                                <email>lennart@poettering.net</email>
+                        </author>
+                </authorgroup>
+        </refentryinfo>
+
+        <refmeta>
+                <refentrytitle>sd_booted</refentrytitle>
+                <manvolnum>3</manvolnum>
+        </refmeta>
+
+        <refnamediv>
+                <refname>sd_booted</refname>
+                <refpurpose>Test whether the system is running the systemd init system.</refpurpose>
+        </refnamediv>
+
+        <refsynopsisdiv>
+                <funcsynopsis>
+                        <funcsynopsisinfo>#include "sd-daemon.h"</funcsynopsisinfo>
+
+                        <funcprototype>
+                                <funcdef>int <function>sd_booted</function></funcdef>
+                                <paramdef>void</paramdef>
+                        </funcprototype>
+                </funcsynopsis>
+        </refsynopsisdiv>
+
+        <refsect1>
+                <title>Description</title>
+                <para><function>sd_booted()</function> checks whether
+                the system was booted up using the systemd init system.</para>
+        </refsect1>
+
+        <refsect1>
+                <title>Return Value</title>
+
+                <para>On failure, this call returns a negative
+                errno-style error code. If the system was booted up
+                with systemd as init system this call returns a
+                postive return value, zero otherwise.</para>
+        </refsect1>
+
+        <refsect1>
+                <title>Notes</title>
+
+                <para>This function is provided by the reference
+                implementation of APIs for new-style daemons and
+                distributed with the systemd package. The algorithm it
+                implements is simple, and can easily be reimplemented
+                in daemons if it is important to support this
+                interface without using the reference
+                implementation.</para>
+
+                <para>Internally, this function checks whether the
+                <filename>/cgroup/systemd</filename> virtual file
+                system is mounted, by comparing the st_dev value of
+                the <function>stat()</function> data of
+                <filename>/cgroup</filename> and
+                <filename>/cgroup/systemd</filename>.</para>
+
+                <para>For details about the algorithm check the
+                liberally licensed reference implementation sources:
+                <ulink url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.c"/>
+                resp. <ulink
+                url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.h"/></para>
+
+                <para><function>sd_booted()</function> is implemented
+                in the reference implementation's drop-in
+                <filename>sd-daemon.c</filename> and
+                <filename>sd-daemon.h</filename> files. It is
+                recommended that applications consuming these APIs
+                copy the implementation into their source tree. For
+                more details about the reference implementation see
+                <citerefentry><refentrytitle>sd_daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry></para>
+
+                <para>If -DDISABLE_SYSTEMD is set during compilation
+                this function will always return 0 and otherwise
+                become a NOP.</para>
+        </refsect1>
+
+        <refsect1>
+                <title>See Also</title>
+                <para>
+                        <citerefentry><refentrytitle>sd_daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+                </para>
+        </refsect1>
+
+</refentry>
diff --git a/man/sd_is_fifo.xml b/man/sd_is_fifo.xml
new file mode 100644
index 0000000000..2389546130
--- /dev/null
+++ b/man/sd_is_fifo.xml
@@ -0,0 +1,199 @@
+<?xml version='1.0'?> <!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+        "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+
+<!--
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+-->
+
+<refentry id="sd_is_fifo">
+
+        <refentryinfo>
+                <title>sd_is_fifo</title>
+                <productname>systemd</productname>
+
+                <authorgroup>
+                        <author>
+                                <contrib>Developer</contrib>
+                                <firstname>Lennart</firstname>
+                                <surname>Poettering</surname>
+                                <email>lennart@poettering.net</email>
+                        </author>
+                </authorgroup>
+        </refentryinfo>
+
+        <refmeta>
+                <refentrytitle>sd_is_fifo</refentrytitle>
+                <manvolnum>3</manvolnum>
+        </refmeta>
+
+        <refnamediv>
+                <refname>sd_is_fifo</refname>
+                <refname>sd_is_socket</refname>
+                <refname>sd_is_socket_inet</refname>
+                <refname>sd_is_socket_unix</refname>
+                <refpurpose>Check the type of a file descriptor</refpurpose>
+        </refnamediv>
+
+        <refsynopsisdiv>
+                <funcsynopsis>
+                        <funcsynopsisinfo>#include "sd-daemon.h"</funcsynopsisinfo>
+
+                        <funcprototype>
+                                <funcdef>int <function>sd_is_fifo</function></funcdef>
+                                <paramdef>int <parameter>fd</parameter></paramdef>
+                                <paramdef>const char *<parameter>path</parameter></paramdef>
+                        </funcprototype>
+
+                        <funcprototype>
+                                <funcdef>int <function>sd_is_socket</function></funcdef>
+                                <paramdef>int <parameter>fd</parameter></paramdef>
+                                <paramdef>int <parameter>family</parameter></paramdef>
+                                <paramdef>int <parameter>type</parameter></paramdef>
+                                <paramdef>int <parameter>listening</parameter></paramdef>
+                        </funcprototype>
+
+                        <funcprototype>
+                                <funcdef>int <function>sd_is_socket_inet</function></funcdef>
+                                <paramdef>int <parameter>fd</parameter></paramdef>
+                                <paramdef>int <parameter>family</parameter></paramdef>
+                                <paramdef>int <parameter>type</parameter></paramdef>
+                                <paramdef>int <parameter>listening</parameter></paramdef>
+                                <paramdef>uint16_t <parameter>port</parameter></paramdef>
+                        </funcprototype>
+
+                        <funcprototype>
+                                <funcdef>int <function>sd_is_socket_unix</function></funcdef>
+                                <paramdef>int <parameter>fd</parameter></paramdef>
+                                <paramdef>int <parameter>type</parameter></paramdef>
+                                <paramdef>int <parameter>listening</parameter></paramdef>
+                                <paramdef>const char* <parameter>path</parameter></paramdef>
+                                <paramdef>size_t <parameter>length</parameter></paramdef>
+                        </funcprototype>
+
+                </funcsynopsis>
+        </refsynopsisdiv>
+
+        <refsect1>
+                <title>Description</title>
+
+                <para><function>sd_is_fifo()</function> may be called
+                to check whether the specified file descriptor refers
+                to a FIFO or pipe. It the <parameter>path</parameter>
+                parameter is not NULL it is checked whether the FIFO
+                is bound to the specified file system path.</para>
+
+                <para><function>sd_is_socket()</function> may be
+                called to check whether the specified file descriptor
+                refers to a socket. It the
+                <parameter>family</parameter> parameter is not
+                AF_UNSPEC it is checked whether the socket is of the
+                specified family (AF_UNIX, AF_INET, ...). If the
+                <parameter>type</parameter> parameter is not 0 it is
+                checked whether the socket is of the specified type
+                (SOCK_STREAM, SOCK_DGRAM, ...). If the
+                <parameter>listening</parameter> parameter is positive
+                it is checked whether the socket is in accepting mode,
+                i.e. <function>listen()</function> has been called for
+                it. If <parameter>listening</parameter> is 0, it is
+                checked whether the socket is not in this mode. If the
+                parameter is negative, no such check is made. The
+                <parameter>listening</parameter> parameter should only
+                be used for stream sockets and should be set to a
+                negative value otherwise.</para>
+
+                <para><function>sd_is_socket_inet()</function> is
+                similar to <function>sd_is_socket()</function>, but
+                optionally checks the IPv4 or IPv6 port number the
+                socket is bound to, unless <parameter>port</parameter>
+                is zero. For this call <parameter>family</parameter>
+                must be passed as either AF_UNSPEC, AF_INET or
+                AF_INET6.</para>
+
+                <para><function>sd_is_socket_unix()</function> is
+                similar to <function>sd_is_socket()</function>, but
+                optionally checks the AF_UNIX path the socket is bound
+                to, unless the <parameter>path</parameter> parameter
+                is NULL. For normal file system AF_UNIX sockets set
+                the <parameter>length</parameter> parameter to 0. For
+                Linux abstract namespace sockets set the
+                <parameter>length</parameter> to the size of the
+                address, including the initial 0 byte and set
+                <parameter>path</parameter> to the initial 0 byte of
+                the socket address.</para>
+        </refsect1>
+
+        <refsect1>
+                <title>Return Value</title>
+
+                <para>On failure, these calls return a negative
+                errno-style error code. If the file descriptor is of
+                the specified type and bound to the specified address
+                a positive return value is returned, otherwise
+                zero.</para>
+        </refsect1>
+
+        <refsect1>
+                <title>Notes</title>
+
+                <para>These functions are provided by the reference
+                implementation of APIs for new-style daemons and
+                distributed with the systemd package. The algorithms
+                they implement are simple, and can easily be
+                reimplemented in daemons if it is important to support
+                this interface without using the reference
+                implementation.</para>
+
+                <para>Internally, these function use a combination of
+                <filename>fstat()</filename> and
+                <filename>getsockname()</filename> to check the file
+                descriptor type and where it is bound to.</para>
+
+                <para>For details about the algorithm check the
+                liberally licensed reference implementation sources:
+                <ulink url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.c"/>
+                resp. <ulink
+                url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.h"/></para>
+
+                <para><function>sd_is_fifo()</function> and the
+                related functions are implemented in the reference
+                implementation's drop-in
+                <filename>sd-daemon.c</filename> and
+                <filename>sd-daemon.h</filename> files. It is
+                recommended that applications consuming these APIs
+                copy the implementation into their source tree. For
+                more details about the reference implementation see
+                <citerefentry><refentrytitle>sd_daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry></para>
+
+                <para>These functions continue to work as described,
+                even if -DDISABLE_SYSTEMD is set during
+                compilation.</para>
+        </refsect1>
+
+        <refsect1>
+                <title>See Also</title>
+                <para>
+                        <citerefentry><refentrytitle>sd_daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+        </para>
+        </refsect1>
+
+</refentry>
diff --git a/man/sd_listen_fds.xml b/man/sd_listen_fds.xml
new file mode 100644
index 0000000000..10ea57c972
--- /dev/null
+++ b/man/sd_listen_fds.xml
@@ -0,0 +1,178 @@
+<?xml version='1.0'?> <!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+        "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+
+<!--
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+-->
+
+<refentry id="sd_listen_fds">
+
+        <refentryinfo>
+                <title>sd_listen_fds</title>
+                <productname>systemd</productname>
+
+                <authorgroup>
+                        <author>
+                                <contrib>Developer</contrib>
+                                <firstname>Lennart</firstname>
+                                <surname>Poettering</surname>
+                                <email>lennart@poettering.net</email>
+                        </author>
+                </authorgroup>
+        </refentryinfo>
+
+        <refmeta>
+                <refentrytitle>sd_listen_fds</refentrytitle>
+                <manvolnum>3</manvolnum>
+        </refmeta>
+
+        <refnamediv>
+                <refname>sd_listen_fds</refname>
+                <refpurpose>Check for file descriptors passed by the init system.</refpurpose>
+        </refnamediv>
+
+        <refsynopsisdiv>
+                <funcsynopsis>
+                        <funcsynopsisinfo>#include "sd-daemon.h"</funcsynopsisinfo>
+
+                        <funcsynopsisinfo>#define SD_LISTEN_FDS_START 3</funcsynopsisinfo>
+
+                        <funcprototype>
+                                <funcdef>int <function>sd_listen_fds</function></funcdef>
+                                <paramdef>int <parameter>unset_environment</parameter></paramdef>
+                        </funcprototype>
+                </funcsynopsis>
+        </refsynopsisdiv>
+
+        <refsect1>
+                <title>Description</title>
+
+                <para><function>sd_listen_fds()</function> shall be
+                called by a daemon to check for file descriptors
+                passed by the init system as part of the socket-based
+                activation logic.</para>
+
+                <para>If the <parameter>unset_environment</parameter>
+                parameter is non-zero
+                <function>sd_listen_fds()</function> will unset the
+                <varname>$LISTEN_FDS</varname>/<varname>$LISTEN_PID</varname>
+                environment variables before returning (regardless
+                whether the function call itself succeeded or
+                not). Further calls to
+                <function>sd_listen_fds()</function> will then fail,
+                but the variables are no longer inherited by child
+                processes.</para>
+
+                <para>If a daemon receives more than one file
+                descriptor, they will be passed in the same order as
+                configured in the systemd socket definition
+                file. Nonetheless it is recommended to verify the
+                correct socket types before using them. To simplify
+                this checking the functions
+                <citerefentry><refentrytitle>sd_is_fifo</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>sd_is_socket</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>sd_is_socket_inet</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                <citerefentry><refentrytitle>sd_is_socket_unix</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+                are provided. In order to maximize flexibility it is
+                recommened to make these checks as loose as possible
+                without allowing incorrect setups. i.e. often the
+                actual port number a socket is bound to matters little
+                for the service to work, hence it should not be
+                verified. On the other hand, whether a socket is a
+                datagram or stream socket matters a lot for the most
+                common program logics and should hence be
+                checked.</para>
+
+                <para>This function call will set the FD_CLOEXEC flag
+                for all passed file descriptors to avoid further
+                inheritance to children of the calling process.</para>
+        </refsect1>
+
+        <refsect1>
+                <title>Return Value</title>
+
+                <para>On failure, this call returns a negative
+                errno-style error code. If
+                <varname>$LISTEN_FDS</varname>/<varname>$LISTEN_PID</varname>
+                was not set or not correctly set for this daemon and
+                hence no file descriptors received 0 is
+                returned. Otherwise the number of file descriptors
+                passed is returned, the application may find them
+                starting with file descriptor SD_LISTEN_FDS_START,
+                i.e. file descriptor 3.</para>
+        </refsect1>
+
+        <refsect1>
+                <title>Notes</title>
+
+                <para>This function is provided by the reference
+                implementation of APIs for new-style daemons and
+                distributed with the systemd package. The algorithm it
+                implements is simple, and can easily be reimplemented
+                in daemons if it is important to support this
+                interface without using the reference
+                implementation.</para>
+
+                <para>Internally, this function checks whether the
+                <varname>$LISTEN_PID</varname> environment variable
+                equals the daemon PID. If not, it returns
+                immediately. Otherwise it parses the number passed in
+                the <varname>$LISTEN_FDS</varname> environment
+                variable, then sets the FD_CLOEXEC flag for the parsed
+                number of file descriptors starting from
+                SD_LISTEN_FDS_START. Finally it returns the parsed
+                number.</para>
+
+                <para>For details about the algorithm check the
+                liberally licensed reference implementation sources:
+                <ulink url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.c"/>
+                resp. <ulink
+                url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.h"/></para>
+
+                <para><function>sd_listen_fds()</function> is
+                implemented in the reference implementation's drop-in
+                <filename>sd-daemon.c</filename> and
+                <filename>sd-daemon.h</filename> files. It is
+                recommended that applications consuming these APIs
+                copy the implementation into their source tree. For
+                more details about the reference implementation see
+                <citerefentry><refentrytitle>sd_daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry></para>
+
+                <para>If -DDISABLE_SYSTEMD is set during compilation
+                this function will always return 0 and otherwise
+                become a NOP.</para>
+        </refsect1>
+
+        <refsect1>
+                <title>See Also</title>
+
+                <para>
+                        <citerefentry><refentrytitle>sd_daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>sd_is_fifo</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>sd_is_socket</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>sd_is_socket_inet</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>sd_is_socket_unix</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+                </para>
+        </refsect1>
+
+</refentry>
diff --git a/man/sd_notify.xml b/man/sd_notify.xml
new file mode 100644
index 0000000000..140e795979
--- /dev/null
+++ b/man/sd_notify.xml
@@ -0,0 +1,277 @@
+<?xml version='1.0'?> <!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+        "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+
+<!--
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+-->
+
+<refentry id="sd_notify">
+
+        <refentryinfo>
+                <title>sd_notify</title>
+                <productname>systemd</productname>
+
+                <authorgroup>
+                        <author>
+                                <contrib>Developer</contrib>
+                                <firstname>Lennart</firstname>
+                                <surname>Poettering</surname>
+                                <email>lennart@poettering.net</email>
+                        </author>
+                </authorgroup>
+        </refentryinfo>
+
+        <refmeta>
+                <refentrytitle>sd_notify</refentrytitle>
+                <manvolnum>3</manvolnum>
+        </refmeta>
+
+        <refnamediv>
+                <refname>sd_notify</refname>
+                <refname>sd_notifyf</refname>
+                <refpurpose>Notify init system about start-up completion and other daemon status changes</refpurpose>
+        </refnamediv>
+
+        <refsynopsisdiv>
+                <funcsynopsis>
+                        <funcsynopsisinfo>#include "sd-daemon.h"</funcsynopsisinfo>
+
+                        <funcprototype>
+                                <funcdef>int <function>sd_notify</function></funcdef>
+                                <paramdef>int <parameter>unset_environment</parameter></paramdef>
+                                <paramdef>const char *<parameter>state</parameter></paramdef>
+                        </funcprototype>
+
+                        <funcprototype>
+                                <funcdef>int <function>sd_notifyf</function></funcdef>
+                                <paramdef>int <parameter>unset_environment</parameter></paramdef>
+                                <paramdef>const char *<parameter>format</parameter></paramdef>
+                                <paramdef>...</paramdef>
+                        </funcprototype>
+                </funcsynopsis>
+        </refsynopsisdiv>
+
+        <refsect1>
+                <title>Description</title>
+                <para><function>sd_notify()</function> shall be called
+                by a daemon to notify the init system about status
+                changes. It can be used to send arbitrary information,
+                encoded in an environment-block-like string. Most
+                importantly it can be used for start-up completion
+                notification.</para>
+
+                <para>If the <parameter>unset_environment</parameter>
+                parameter is non-zero <function>sd_notify()</function>
+                will unset the <varname>$NOTIFY_SOCKET</varname>
+                environment variable before returning (regardless
+                whether the function call itself succeeded or
+                not). Further calls to
+                <function>sd_notify()</function> will then fail, but
+                the variable is no longer inherited by child
+                processes.</para>
+
+                <para>The <parameter>state</parameter> parameter
+                should contain an newline-seperated list of variable
+                assignments, similar in style to an environment
+                block. A trailing newline is implied if none is
+                specified. The string may contain any kind of variable
+                assignments, but the following shall be considered
+                well-known:</para>
+
+                <variablelist>
+                        <varlistentry>
+                                <term>READY=1</term>
+
+                                <listitem><para>Tells the init system
+                                that daemon startup is finished. This
+                                is only used by systemd if the service
+                                definition file has Type=notify
+                                set. The passed argument is a boolean
+                                "1" or "0". Since there is little
+                                value in signalling non-readiness the
+                                only value daemons should send is
+                                "READY=1".</para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term>STATUS=...</term>
+
+                                <listitem><para>Passes a single-line
+                                status string back to the init system
+                                that describes the daemon state. This
+                                is free-from and can be used for
+                                various purposes: general state
+                                feedback, fsck-like programs could
+                                pass completion percentages and
+                                failing programs could pass a human
+                                readable error message. Example:
+                                "STATUS=Completed 66% of file system
+                                check..."</para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term>ERRNO=...</term>
+
+                                <listitem><para>If a daemon fails, the
+                                errno-style error code, formatted as
+                                string. Example: "ERRNO=2" for
+                                ENOENT.</para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term>BUSERROR=...</term>
+
+                                <listitem><para>If a daemon fails, the
+                                D-Bus error-style error code. Example:
+                                "BUSERROR=org.freedesktop.DBus.Error.TimedOut"</para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
+                                <term>MAINPID=...</term>
+
+                                <listitem><para>The main pid of the
+                                daemon, in case the init system did
+                                not fork off the process
+                                itself. Example:
+                                "MAINPID=4711"</para></listitem>
+                        </varlistentry>
+                </variablelist>
+
+                <para>It is recommened to prefix variable names that
+                are not shown in the list above with
+                <varname>X_</varname> to avoid namespace
+                clashes.</para>
+
+                <para>Note that systemd will accept status data sent
+                from a daemon only if the
+                <varname>NotifyAccess=</varname> option is correctly
+                set in the service definition file. See
+                <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+                for details.</para>
+
+                <para><function>sd_notifyf()</function> is similar to
+                <function>sd_notifyf()</function> but takes a
+                <function>printf()</function>-like format string plus
+                arguments.</para>
+        </refsect1>
+
+        <refsect1>
+                <title>Return Value</title>
+
+                <para>On failure, these calls return a negative
+                errno-style error code. If
+                <varname>$NOTIFY_SOCKET</varname> was not set and
+                hence no status data could be sent 0 is returned. If
+                the status was sent these functions return with a
+                positive return value. In order to support both init
+                systems that implement this scheme and those which
+                don't it is generally recommended to ignore the return
+                value of this call.</para>
+        </refsect1>
+
+        <refsect1>
+                <title>Notes</title>
+
+                <para>These functions are provided by the reference
+                implementation of APIs for new-style daemons and
+                distributed with the systemd package. The algorithms
+                they implement are simple, and can easily be
+                reimplemented in daemons if it is important to support
+                this interface without using the reference
+                implementation.</para>
+
+                <para>Internally, these functions send a single
+                datagram with the state string as payload to the
+                AF_UNIX socket referenced in the
+                <varname>$NOTIFY_SOCKET</varname> environment
+                variable. If the first character of
+                <varname>$NOTIFY_SOCKET</varname> is @ the string is
+                understood as Linux abstract namespace socket. The
+                datagram is accompanied by the process credentials of
+                the sending daemon, using SCM_CREDENTIALS.</para>
+
+                <para>For details about the algorithm check the
+                liberally licensed reference implementation sources:
+                <ulink url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.c"/>
+                resp. <ulink
+                url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.h"/></para>
+
+                <para><function>sd_notify()</function> and
+                <function>sd_notifyf()</function> are implemented in
+                the reference implementation's drop-in
+                <filename>sd-daemon.c</filename> and
+                <filename>sd-daemon.h</filename> files. It is
+                recommended that applications consuming these APIs
+                copy the implementation into their source tree. For
+                more details about the reference implementation see
+                <citerefentry><refentrytitle>sd_daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry></para>
+
+                <para>If -DDISABLE_SYSTEMD is set during compilation
+                this function will always return 0 and otherwise
+                become a NOP.</para>
+        </refsect1>
+
+        <refsect1>
+                <title>Examples</title>
+
+                <example>
+                        <title>Start-up Notification</title>
+
+                        <para>When a daemon finished starting up, it
+                        might issue the following call call to notify
+                        the init system:</para>
+
+                        <programlisting>sd_notify(0, "READY=1");</programlisting>
+                </example>
+
+                <example>
+                        <title>Extended Start-up Notification</title>
+
+                        <para>A daemon could send the following after
+                        completing initialization:</para>
+
+                        <programlisting>sd_notifyf(0, "READY=1\n"
+              "STATUS=Processing requests...\n"
+              "MAINPID=%lu",
+              (unsigned long) getpid());</programlisting>
+                </example>
+
+                <example>
+                        <title>Error Cause Notification</title>
+
+                        <para>A daemon could send the following shortly before exiting, on failure</para>
+
+                        <programlisting>sd_notifyf(0, "STATUS=Failed to start up: %s\n"
+              "ERRNO=%i",
+              strerror(errno),
+              errno);</programlisting>
+                </example>
+        </refsect1>
+
+        <refsect1>
+                <title>See Also</title>
+                <para>
+                        <citerefentry><refentrytitle>sd_daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+                        <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+                </para>
+        </refsect1>
+
+</refentry>