mirror of
https://github.com/systemd/systemd.git
synced 2024-11-05 15:21:37 +03:00
cb07866b1b
This way we can include documentation about minor macros/inline function within the introducionary man page in a sane way.
218 lines
11 KiB
XML
218 lines
11 KiB
XML
<?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_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>
|
|
<refname>sd_is_mq</refname>
|
|
<refpurpose>Check the type of a file descriptor</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<funcsynopsis>
|
|
<funcsynopsisinfo>#include <systemd/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>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_is_mq</function></funcdef>
|
|
<paramdef>int <parameter>fd</parameter></paramdef>
|
|
<paramdef>const char *<parameter>path</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. If 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>
|
|
|
|
<para><function>sd_is_mq()</function> may be called to
|
|
check whether the specified file descriptor refers to
|
|
a POSIX message queue. If the
|
|
<parameter>path</parameter> parameter is not NULL, it
|
|
is checked whether the message queue is bound to the
|
|
specified name.</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 algorithms check the
|
|
liberally licensed reference implementation sources:
|
|
<ulink url="http://cgit.freedesktop.org/systemd/systemd/plain/src/sd-daemon.c"/>
|
|
resp. <ulink
|
|
url="http://cgit.freedesktop.org/systemd/systemd/plain/src/systemd/sd-daemon.h"/></para>
|
|
|
|
<para><function>sd_is_fifo()</function> and the
|
|
related functions are implemented in the reference
|
|
implementation's <filename>sd-daemon.c</filename> and
|
|
<filename>sd-daemon.h</filename> files. These
|
|
interfaces are available as shared library, which can
|
|
be compiled and linked to with the
|
|
<literal>libsystemd-daemon</literal>
|
|
<citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
|
file. Alternatively, applications consuming these APIs
|
|
may copy the implementation into their source
|
|
tree. For more details about the reference
|
|
implementation see
|
|
<citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</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>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>
|
|
</para>
|
|
</refsect1>
|
|
|
|
</refentry>
|