derek Sun Jan 18 15:25:16 2004 EDT
Modified files:
/phpdoc/en/reference/sockets/functions socket-create-pair.xml
Log:
Adding documentation
Index: phpdoc/en/reference/sockets/functions/socket-create-pair.xml
diff -u phpdoc/en/reference/sockets/functions/socket-create-pair.xml:1.2
phpdoc/en/reference/sockets/functions/socket-create-pair.xml:1.3
--- phpdoc/en/reference/sockets/functions/socket-create-pair.xml:1.2 Wed Apr 17
02:44:07 2002
+++ phpdoc/en/reference/sockets/functions/socket-create-pair.xml Sun Jan 18
15:25:16 2004
@@ -1,5 +1,5 @@
<?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.2 $ -->
+<!-- $Revision: 1.3 $ -->
<!-- splitted from ./en/functions/sockets.xml, last change in rev 1.27 -->
<refentry id="function.socket-create-pair">
<refnamediv>
@@ -17,7 +17,223 @@
</methodsynopsis>
&warn.experimental.func;
<para>
- &warn.undocumented.func;
+ <function>socket_create_pair</function> creates two connected and
indistinguishable sockets, and stores
+ them in <parameter>&fd</parameter>. This function is common used in IPC
(InterProcess Communication).
+ </para>
+ <para>
+ The <parameter>domain</parameter> parameter specifies the protocol
+ family to be used by the socket.
+ </para>
+ <table>
+ <title>Available address/protocol families</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>Domain</entry>
+ <entry>Description</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>AF_INET</entry>
+ <entry>
+ IPv4 Internet based protocols. TCP and UDP are common protocols of
+ this protocol family. Supported only in windows.
+ </entry>
+ </row>
+ <row>
+ <entry>AF_INET6</entry>
+ <entry>
+ IPv6 Internet based protocols. TCP and UDP are common protocols of
+ this protocol family. Support added in <literal>PHP 5.0.0</literal>.
+ Supported only in windows.
+ </entry>
+ </row>
+ <row>
+ <entry>AF_UNIX</entry>
+ <entry>
+ Local communication protocol family. High efficiency and low
+ overhead make it a great form of IPC (Interprocess Communication).
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <para>
+ The <parameter>type</parameter> parameter selects the type of communication
+ to be used by the socket.
+ </para>
+ <table>
+ <title>Available socket types</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>Type</entry>
+ <entry>Description</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>SOCK_STREAM</entry>
+ <entry>
+ Provides sequenced, reliable, full-duplex, connection-based byte streams.
+ An out-of-band data transmission mechanism may be supported.
+ The TCP protocol is based on this socket type.
+ </entry>
+ </row>
+ <row>
+ <entry>SOCK_DGRAM</entry>
+ <entry>
+ Supports datagrams (connectionless, unreliable messages of a fixed maximum
length).
+ The UDP protocol is based on this socket type.
+ </entry>
+ </row>
+ <row>
+ <entry>SOCK_SEQPACKET</entry>
+ <entry>
+ Provides a sequenced, reliable, two-way connection-based data transmission
path for
+ datagrams of fixed maximum length; a consumer is required to read an
+ entire packet with each read call.
+ </entry>
+ </row>
+ <row>
+ <entry>SOCK_RAW</entry>
+ <entry>
+ Provides raw network protocol access. This special type of socket
+ can be used to manually construct any type of protocol. A common use
+ for this socket type is to perform ICMP requests (like ping,
+ traceroute, etc).
+ </entry>
+ </row>
+ <row>
+ <entry>SOCK_RDM</entry>
+ <entry>
+ Provides a reliable datagram layer that does not guarantee ordering.
+ This is most likely not implemented on your operating system.
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <para>
+ The <parameter>protocol</parameter> parameter sets the specific
+ protocol within the specified <parameter>domain</parameter> to be used
+ when communicating on the returned socket. The proper value can be retrieved by
+ name by using <function>getprotobyname</function>. If
+ the desired protocol is TCP, or UDP the corresponding constants
+ <constant>SOL_TCP</constant>, and <constant>SOL_UDP</constant>
+ can also be used.
+ </para>
+ <table>
+ <title>Common protocols</title>
+ <tgroup cols="2">
+ <thead>
+ <row>
+ <entry>Name</entry>
+ <entry>Description</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>icmp</entry>
+ <entry>
+ The Internet Control Message Protocol is used primarily by gateways
+ and hosts to report errors in datagram communication. The "ping"
+ command (present in most modern operating systems) is an example
+ application of ICMP.
+ </entry>
+ </row>
+ <row>
+ <entry>udp</entry>
+ <entry>
+ The User Datagram Protocol is a connectionless, unreliable,
+ protocol with fixed record lengths. Due to these aspects, UDP
+ requires a minimum amount of protocol overhead.
+ </entry>
+ </row>
+ <row>
+ <entry>tcp</entry>
+ <entry>
+ The Transmission Control Protocol is a reliable, connection based,
+ stream oriented, full duplex protocol. TCP guarantees that all data packets
+ will be received in the order in which they were sent. If any packet is
somehow
+ lost during communication, TCP will automatically retransmit the packet until
+ the destination host acknowledges that packet. For reliability and performance
+ reasons, the TCP implementation itself decides the appropriate octet
boundaries
+ of the underlying datagram communication layer. Therefore, TCP applications
must
+ allow for the possibility of partial record transmission.
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <para>
+ <example>
+ <title><function>socket_create_pair</function> example</title>
+ <programlisting role="php">
+<![CDATA[
+<?php
+$sockets = array();
+$uniqid = uniqid("");
+if (file_exists("/tmp/$uniqid.sock"))
+ die('Temporary socket already exists.');
+
+/* Setup socket pair */
+if(!socket_create_pair(AF_UNIX, SOCK_STREAM, 0, $sockets))
+ echo socket_strerror(socket_last_error());
+
+/* Send and Recieve Data */
+if(!socket_write($sockets[0], "ABCdef123\n", strlen("ABCdef123\n")))
+ echo socket_strerror(socket_last_error());
+
+if(!$data = socket_read($sockets[1], strlen("ABCdef123\n"), PHP_BINARY_READ))
+ echo socket_strerror(socket_last_error());
+
+var_dump($data);
+
+/* Close sockets */
+socket_close($sockets[0]);
+socket_close($sockets[1]);
+?>
+]]>
+ </programlisting>
+ </example>
+ </para>
+ <para>
+ <example>
+ <title><function>socket_create_pair</function> IPC example</title>
+ <programlisting role="php">
+<![CDATA[
+<?php
+$ary = array();
+$strone = 'Message From Parent.';
+$strtwo = 'Message From Child.';
+if(!socket_create_pair(AF_UNIX, SOCK_STREAM, 0, $ary))
+ echo socket_strerror(socket_last_error());
+
+$pid = pcntl_fork();
+if($pid == -1)
+{
+ echo 'Could not fork Process.';
+} elseif( $pid ) {
+ /*parent*/
+ socket_close($ary[0]);
+ if(!socket_write($ary[1], $strone, strlen($strone))
+ echo socket_strerror(socket_last_error());
+ if(socket_read($ary[1], strlen($strtwo), PHP_BINARY_READ) == $strtwo)
+ echo 'Recieved ', $strtwo;
+} else {
+ /*child*/
+ socket_close($ary[1]);
+ if(!socket_write($ary[0], $strtwo, strlen($strtwo))
+ echo socket_strerror(socket_last_error());
+ if(socket_read($ary[0], strlen($strone), PHP_BINARY_READ) == $strone)
+ echo 'Recieved ', $strone;
+}
+?>
+]]>
+ </programlisting>
+ </example>
</para>
</refsect1>
</refentry>
