mirror of
https://github.com/systemd/systemd.git
synced 2024-12-03 23:33:38 +08:00
211 lines
10 KiB
XML
211 lines
10 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>
|
||
<refname>sd_is_special</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>
|
||
|
||
<funcprototype>
|
||
<funcdef>int <function>sd_is_special</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 <constant>NULL</constant>, 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. If the
|
||
<parameter>family</parameter> parameter is not
|
||
<constant>AF_UNSPEC</constant>, it is checked whether
|
||
the socket is of the specified family (AF_UNIX,
|
||
<constant>AF_INET</constant>, ...). If the
|
||
<parameter>type</parameter> parameter is not 0, it is
|
||
checked whether the socket is of the specified type
|
||
(<constant>SOCK_STREAM</constant>,
|
||
<constant>SOCK_DGRAM</constant>, ...). 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 <constant>AF_UNSPEC</constant>, <constant>AF_INET</constant>, or
|
||
<constant>AF_INET6</constant>.</para>
|
||
|
||
<para><function>sd_is_socket_unix()</function> is
|
||
similar to <function>sd_is_socket()</function> but
|
||
optionally checks the <constant>AF_UNIX</constant> path the socket is bound
|
||
to, unless the <parameter>path</parameter> parameter
|
||
is <constant>NULL</constant>. For normal file system <constant>AF_UNIX</constant> 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 the
|
||
<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
|
||
<constant>NULL</constant>, it is checked whether the
|
||
message queue is bound to the specified name.</para>
|
||
|
||
<para><function>sd_is_special()</function> may be
|
||
called to check whether the specified file descriptor
|
||
refers to a special file. If the
|
||
<parameter>path</parameter> parameter is not
|
||
<constant>NULL</constant>, it is checked whether the file
|
||
descriptor is bound to the specified file
|
||
name. Special files in this context are character
|
||
device nodes and files in <filename>/proc</filename>
|
||
or <filename>/sys</filename>.</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 APIs are implemented as a shared library,
|
||
which can be compiled and linked to with the
|
||
<constant>libsystemd</constant> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
||
file.</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>
|
||
</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>
|