chiark / gitweb /
namespace: include boot id in private tmp directories
[elogind.git] / man / sd_is_fifo.xml
index f1f6d37..4d9cd79 100644 (file)
@@ -8,16 +8,16 @@
   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
+  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
-  General Public License for more details.
+  Lesser General Public License for more details.
 
-  You should have received a copy of the GNU General Public License
+  You should have received a copy of the GNU Lesser General Public License
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 -->
 
                 <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 "sd-daemon.h"</funcsynopsisinfo>
+                        <funcsynopsisinfo>#include &lt;systemd/sd-daemon.h&gt;</funcsynopsisinfo>
 
                         <funcprototype>
                                 <funcdef>int <function>sd_is_fifo</function></funcdef>
                                 <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>
 
 
                 <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>
+                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. It the
+                refers to a socket. If 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
+                <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
-                (SOCK_STREAM, SOCK_DGRAM, ...). If the
-                <parameter>listening</parameter> parameter is positive
+                (<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
                 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>
+                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 AF_UNIX path the socket is bound
+                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 NULL. For normal file system AF_UNIX sockets set
-                the <parameter>length</parameter> parameter to 0. For
-                Linux abstract namespace sockets set the
+                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
+                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 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>
 
                 <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
+                the specified type and bound to the specified address,
                 a positive return value is returned, otherwise
                 zero.</para>
         </refsect1>
                 <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
+                they implement are simple, and they can easily be
                 reimplemented in daemons if it is important to support
                 this interface without using the reference
                 implementation.</para>
                 <filename>getsockname()</filename> to check the file
                 descriptor type and where it is bound to.</para>
 
-                <para>For details about the algorithm check the
+                <para>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>
+                <ulink url="http://cgit.freedesktop.org/systemd/systemd/plain/src/libsystemd-daemon/sd-daemon.c"/>
+                and <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 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>
+                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
+                <constant>libsystemd-daemon</constant> <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
                 <title>See Also</title>
                 <para>
                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
-                        <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>7</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>
+                </para>
         </refsect1>
 
 </refentry>