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Diffstat (limited to 'man/sd_listen_fds.xml')
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diff --git a/man/sd_listen_fds.xml b/man/sd_listen_fds.xml deleted file mode 100644 index 9b9705eb2..000000000 --- a/man/sd_listen_fds.xml +++ /dev/null @@ -1,176 +0,0 @@ -<?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 Lesser General Public License as published by - the Free Software Foundation; either version 2.1 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 - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. ---> - -<refentry id="sd_listen_fds" - xmlns:xi="http://www.w3.org/2001/XInclude"> - - <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> - <refname>SD_LISTEN_FDS_START</refname> - <refpurpose>Check for file descriptors passed by the system manager</refpurpose> - </refnamediv> - - <refsynopsisdiv> - <funcsynopsis> - <funcsynopsisinfo>#include <systemd/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>$LISTEN_FDS</varname> and <varname>$LISTEN_PID</varname> - environment variables before returning (regardless of 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 unit file (see - <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry> - for details). 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 recommended - 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 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> - - <para>If multiple socket units activate the same service the order - of the file descriptors passed to its main process is undefined. - If additional file descriptors have been passed to the service - manager using - <citerefentry><refentrytitle>sd_pid_notify_with_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>'s - <literal>FDSTORE=1</literal> messages, these file descriptors are - passed last, in arbitrary order, and with duplicates - removed.</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 was not correctly set for this daemon and hence no file - descriptors were 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> - - <xi:include href="libsystemd-pkgconfig.xml" xpointer="pkgconfig-text"/> - - <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> - </refsect1> - - <refsect1> - <title>Environment</title> - - <variablelist class='environment-variables'> - <varlistentry> - <term><varname>$LISTEN_PID</varname></term> - <term><varname>$LISTEN_FDS</varname></term> - - <listitem><para>Set by the init system - for supervised processes that use - socket-based activation. This - environment variable specifies the - data - <function>sd_listen_fds()</function> - parses. See above for - details.</para></listitem> - </varlistentry> - </variablelist> - </refsect1> - - <refsect1> - <title>See Also</title> - - <para> - <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</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.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>, - <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry> - </para> - </refsect1> - -</refentry> |