mirror of
https://github.com/systemd/systemd.git
synced 2024-12-21 08:03:49 +08:00
202 lines
9.2 KiB
XML
202 lines
9.2 KiB
XML
<?xml version='1.0'?> <!--*-nxml-*-->
|
|
<!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-or-later -->
|
|
|
|
<refentry id="sd_is_fifo"
|
|
xmlns:xi="http://www.w3.org/2001/XInclude">
|
|
|
|
<refentryinfo>
|
|
<title>sd_is_fifo</title>
|
|
<productname>systemd</productname>
|
|
</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_socket_sockaddr</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_sockaddr</function></funcdef>
|
|
<paramdef>int <parameter>fd</parameter></paramdef>
|
|
<paramdef>int <parameter>type</parameter></paramdef>
|
|
<paramdef>const struct sockaddr *<parameter>addr</parameter></paramdef>
|
|
<paramdef>unsigned <parameter>addr_len</parameter></paramdef>
|
|
<paramdef>int <parameter>listening</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 (<constant>AF_UNIX</constant>,
|
|
<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_sockaddr()</function> is similar to
|
|
<function>sd_is_socket_inet()</function>, but checks if the socket is bound to the
|
|
address specified by <parameter>addr</parameter>. The
|
|
<structfield>family</structfield> specified by <parameter>addr</parameter> must be
|
|
either <constant>AF_INET</constant> or <constant>AF_INET6</constant> and
|
|
<parameter>addr_len</parameter> must be large enough for that family. If
|
|
<parameter>addr</parameter> specifies a non-zero port, it is also checked if the
|
|
socket is bound to this port. In addition, for IPv6, if <parameter>addr</parameter>
|
|
specifies non-zero <structfield>sin6_flowinfo</structfield> or
|
|
<structfield>sin6_scope_id</structfield>, it is checked if the socket has the same
|
|
values.</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 filename. 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>
|
|
|
|
<xi:include href="libsystemd-pkgconfig.xml" xpointer="pkgconfig-text"/>
|
|
|
|
<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>,
|
|
<citerefentry project='man-pages'><refentrytitle>ip</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
|
|
<citerefentry project='man-pages'><refentrytitle>ipv6</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
|
|
<citerefentry project='man-pages'><refentrytitle>unix</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
|
|
<citerefentry project='man-pages'><refentrytitle>fifo</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
|
|
<citerefentry project='man-pages'><refentrytitle>mq_overview</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
|
|
<citerefentry project='man-pages'><refentrytitle>socket</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
|
|
</para>
|
|
</refsect1>
|
|
|
|
</refentry>
|