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+<?xml version="1.0" encoding="latin1" ?>
+<!DOCTYPE cref SYSTEM "cref.dtd">
+
+<cref>
+  <header>
+    <copyright>
+      <year>1996</year><year>2009</year>
+      <holder>Ericsson AB. All Rights Reserved.</holder>
+    </copyright>
+    <legalnotice>
+      The contents of this file are subject to the Erlang Public License,
+      Version 1.1, (the "License"); you may not use this file except in
+      compliance with the License. You should have received a copy of the
+      Erlang Public License along with this software. If not, it can be
+      retrieved online at http://www.erlang.org/.
+    
+      Software distributed under the License is distributed on an "AS IS"
+      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+      the License for the specific language governing rights and limitations
+      under the License.
+    
+    </legalnotice>
+
+    <title>erl_connect</title>
+    <prepared>Torbj&ouml;rn T&ouml;rnkvist</prepared>
+    <responsible>Torbj&ouml;rn T&ouml;rnkvist</responsible>
+    <docno></docno>
+    <approved>Bjarne D&auml;cker</approved>
+    <checked>Torbj&ouml;rn T&ouml;rnkvist</checked>
+    <date>980703</date>
+    <rev>A</rev>
+    <file>erl_connect.sgml</file>
+  </header>
+  <lib>erl_connect</lib>
+  <libsummary>Communicate with Distributed Erlang</libsummary>
+  <description>
+    <p>This module provides support for communication between distributed
+      Erlang nodes and C nodes, in a manner that is transparent to Erlang
+      processes.</p>
+    <p>A C node appears to Erlang as a
+      <em>hidden node</em>.
+      That is, Erlang processes that know the name of the
+      C node are able to communicate with it in a normal manner, but
+      the node name will not appear in the listing provided by the
+      Erlang function <c><![CDATA[nodes/0]]></c>.</p>
+  </description>
+  <funcs>
+    <func>
+      <name><ret>int</ret><nametext>erl_connect_init(number, cookie, creation)</nametext></name>
+      <name><ret>int</ret><nametext>erl_connect_xinit(host, alive, node, addr, cookie, creation)</nametext></name>
+      <fsummary>Initialize communication</fsummary>
+      <type>
+        <v>int number;</v>
+        <v>char *cookie;</v>
+        <v>short creation;</v>
+        <v>char *host,*alive,*node;</v>
+        <v>struct in_addr *addr;</v>
+      </type>
+      <desc>
+        <p>These functions initialize the <c><![CDATA[erl_connect]]></c>
+          module. In particular, they are used to identify the name of the
+          C-node from which they are called. One of these functions must
+          be called before any of the other functions in the erl_connect 
+          module are used.</p>
+        <p><c><![CDATA[erl_connect_xinit()]]></c> stores for later use information about
+          the node's host name <c><![CDATA[host]]></c>, alive name <c><![CDATA[alive]]></c>, node
+          name <c><![CDATA[node]]></c>, IP address <c><![CDATA[addr]]></c>, cookie <c><![CDATA[cookie]]></c>,
+          and creation number <c><![CDATA[creation]]></c>. <c><![CDATA[erl_connect_init()]]></c>
+          provides an alternative interface which does not require as much
+          information from the caller. Instead, <c><![CDATA[erl_connect_init()]]></c>
+          uses <c><![CDATA[gethostbyname()]]></c> to obtain default values. 
+          </p>
+        <p>If you use <c><![CDATA[erl_connect_init()]]></c> your node will have a
+          short name, i.e., it will not be fully qualified. If you need to
+          use fully qualified (a.k.a. long) names, use
+          <c><![CDATA[erl_connect_xinit()]]></c> instead. 
+          </p>
+        <p><c><![CDATA[host]]></c> is the name of the host on which the node is running.</p>
+        <p><c><![CDATA[alive]]></c> is the alivename of the node.</p>
+        <p><c><![CDATA[node]]></c> is the name of the node. The nodename should
+          be of the form <em>alivename@hostname</em>.</p>
+        <p><c><![CDATA[addr]]></c> is the 32-bit IP address of <c><![CDATA[host]]></c>.</p>
+        <p><c><![CDATA[cookie]]></c> is the authorization string required for access
+          to the remote node. If NULL the user HOME directory is
+          searched for a cookie file <c><![CDATA[.erlang.cookie]]></c>. The path to
+          the home directory is retrieved from the environment variable
+          <c><![CDATA[HOME]]></c> on Unix and from the <c><![CDATA[HOMEDRIVE]]></c> and
+          <c><![CDATA[HOMEPATH]]></c> variables on Windows. Refer to the <c><![CDATA[auth]]></c>
+          module for more details.</p>
+        <p><c><![CDATA[creation]]></c> helps identify a particular instance of a C
+          node. In particular, it can help prevent us from receiving
+          messages sent to an earlier process with the same registered
+          name.</p>
+        <p>A C node acting as a server will be assigned a creation number
+          when it calls <c><![CDATA[erl_publish()]]></c>.</p>
+        <p><c><![CDATA[number]]></c> is used by <c><![CDATA[erl_connect_init()]]></c> to
+          construct the actual node name. In the second example shown
+          below, <em>"[email protected]"</em> will be the resulting node
+          name.</p>
+        <p>Example 1:</p>
+        <code type="none"><![CDATA[
+struct in_addr addr;
+addr = inet_addr("150.236.14.75");
+if (!erl_connect_xinit("chivas",
+                       "madonna",
+                       "[email protected]",
+                       &addr;
+                       "samplecookiestring..."),
+                       0)
+  erl_err_quit("<ERROR> when initializing !");
+        ]]></code>
+        <p>Example 2:</p>
+        <code type="none"><![CDATA[
+if (!erl_connect_init(17, "samplecookiestring...", 0))
+  erl_err_quit("<ERROR> when initializing !");
+        ]]></code>
+      </desc>
+    </func>
+    <func>
+      <name><ret>int</ret><nametext>erl_connect(node)</nametext></name>
+      <name><ret>int</ret><nametext>erl_xconnect(addr, alive)</nametext></name>
+      <fsummary>Establishe a connection to an Erlang node</fsummary>
+      <type>
+        <v>char *node, *alive;</v>
+        <v>struct in_addr *addr;</v>
+      </type>
+      <desc>
+        <p>These functions set up a connection to an Erlang node.</p>
+        <p><c><![CDATA[erl_xconnect()]]></c> requires the IP address of the remote
+          host and the alive name of the remote node
+          to be specified. <c><![CDATA[erl_connect()]]></c> provides an alternative
+          interface, and determines the information from the node name
+          provided.</p>
+        <p><c><![CDATA[addr]]></c> is the 32-bit IP address of the remote host.</p>
+        <p><c><![CDATA[alive]]></c> is the alivename of the remote node.</p>
+        <p><c><![CDATA[node]]></c> is the name of the remote node.</p>
+        <p>These functions return an open file descriptor on success, or
+          a negative value indicating that an error occurred --- in
+          which case they will set <c><![CDATA[erl_errno]]></c> to one of:</p>
+        <taglist>
+          <tag><c><![CDATA[EHOSTUNREACH]]></c></tag>
+          <item>The remote host <c><![CDATA[node]]></c> is unreachable</item>
+          <tag><c><![CDATA[ENOMEM]]></c></tag>
+          <item>No more memory available.</item>
+          <tag><c><![CDATA[EIO]]></c></tag>
+          <item>I/O error.</item>
+        </taglist>
+        <p>Additionally, <c><![CDATA[errno]]></c> values from
+          <c><![CDATA[socket]]></c><em>(2)</em> and <c><![CDATA[connect]]></c><em>(2)</em>
+          system calls may be propagated into <c><![CDATA[erl_errno]]></c>.</p>
+        <code type="none"><![CDATA[
+#define NODE   "[email protected]"
+#define ALIVE  "madonna"
+#define IP_ADDR "150.236.14.75"
+
+/*** Variant 1 ***/
+erl_connect( NODE );
+
+/*** Variant 2 ***/
+struct in_addr addr;
+addr = inet_addr(IP_ADDR);
+erl_xconnect( &addr , ALIVE );
+        ]]></code>
+      </desc>
+    </func>
+    <func>
+      <name><ret>int</ret><nametext>erl_close_connection(fd)</nametext></name>
+      <fsummary>Close a connection to an Erlang node</fsummary>
+      <type>
+        <v>int fd;</v>
+      </type>
+      <desc>
+        <p>This function closes an open connection to an Erlang node.</p>
+        <p><c><![CDATA[Fd]]></c> is a file descriptor obtained from
+          <c><![CDATA[erl_connect()]]></c> or <c><![CDATA[erl_xconnect()]]></c>.</p>
+        <p>On success, 0 is returned. If the call fails, a non-zero value
+          is returned, and the reason for
+          the error can be obtained with the appropriate platform-dependent
+          call.</p>
+      </desc>
+    </func>
+    <func>
+      <name><ret>int</ret><nametext>erl_receive(fd, bufp, bufsize)</nametext></name>
+      <fsummary>Receive a message</fsummary>
+      <type>
+        <v>int fd;</v>
+        <v>char *bufp;</v>
+        <v>int bufsize;</v>
+      </type>
+      <desc>
+        <p>This function receives a message consisting of a sequence
+          of bytes in the Erlang external format.</p>
+        <p><c><![CDATA[fd]]></c> is an open descriptor to an Erlang connection.</p>
+        <p><c><![CDATA[bufp]]></c> is a buffer large enough to hold the expected
+          message. </p>
+        <p><c><![CDATA[bufsize]]></c> indicates the size of <c><![CDATA[bufp]]></c>.</p>
+        <p>If a <em>tick</em> occurs, i.e., the Erlang node on the
+          other end of the connection has polled this node to see if it
+          is still alive, the function will return <c><![CDATA[ERL_TICK]]></c> and
+          no message will be placed in the buffer. Also,
+          <c><![CDATA[erl_errno]]></c> will be set to <c><![CDATA[EAGAIN]]></c>.</p>
+        <p>On success, the message is placed in the specified buffer
+          and the function returns the number of bytes actually read. On
+          failure, the function returns a negative value and will set
+          <c><![CDATA[erl_errno]]></c> to one of:</p>
+        <taglist>
+          <tag><c><![CDATA[EAGAIN]]></c></tag>
+          <item>Temporary error: Try again.</item>
+          <tag><c><![CDATA[EMSGSIZE]]></c></tag>
+          <item>Buffer too small.</item>
+          <tag><c><![CDATA[EIO]]></c></tag>
+          <item>I/O error.</item>
+        </taglist>
+      </desc>
+    </func>
+    <func>
+      <name><ret>int</ret><nametext>erl_receive_msg(fd, bufp, bufsize, emsg)</nametext></name>
+      <fsummary>Receive and decodes a message</fsummary>
+      <type>
+        <v>int fd;</v>
+        <v>unsigned char *bufp;</v>
+        <v>int bufsize;</v>
+        <v>ErlMessage *emsg;</v>
+      </type>
+      <desc>
+        <p>This function receives the message into the specified buffer, 
+          and decodes into the <c><![CDATA[(ErlMessage *) emsg]]></c>.</p>
+        <p><c><![CDATA[fd]]></c> is an open descriptor to an Erlang connection.</p>
+        <p><c><![CDATA[bufp]]></c> is a buffer large enough to hold the expected message.</p>
+        <p><c><![CDATA[bufsize]]></c> indicates the size of <c><![CDATA[bufp]]></c>.</p>
+        <p><c><![CDATA[emsg]]></c> is a pointer to an <c><![CDATA[ErlMessage]]></c> structure,
+          into which the message will be decoded. <c><![CDATA[ErlMessage]]></c> is
+          defined as follows:</p>
+        <code type="none"><![CDATA[
+typedef struct {
+  int type;
+  ETERM *msg;
+  ETERM *to;
+  ETERM *from;
+  char to_name[MAXREGLEN];
+} ErlMessage;
+        ]]></code>
+        <note>
+          <p>The definition of <c><![CDATA[ErlMessage]]></c> has changed since
+            earlier versions of Erl_Interface.</p>
+        </note>
+        <p><c><![CDATA[type]]></c> identifies the type of message, one of 
+          <c><![CDATA[ERL_SEND]]></c>, <c><![CDATA[ERL_REG_SEND]]></c>, <c><![CDATA[ERL_LINK]]></c>,
+          <c><![CDATA[ERL_UNLINK]]></c> and <c><![CDATA[ERL_EXIT]]></c>. 
+          </p>
+        <p>If <c><![CDATA[type]]></c> contains <c><![CDATA[ERL_SEND]]></c>
+          this indicates that an ordinary send operation has taken
+          place, and <c><![CDATA[emsg->to]]></c> contains the Pid of the
+          recipient. If <c><![CDATA[type]]></c> contains <c><![CDATA[ERL_REG_SEND]]></c> then a
+          registered send operation took place, and <c><![CDATA[emsg->from]]></c>
+          contains the Pid of the sender. In both cases, the actual
+          message will be in <c><![CDATA[emsg->msg]]></c>.
+          </p>
+        <p>If <c><![CDATA[type]]></c> contains one of <c><![CDATA[ERL_LINK]]></c> or
+          <c><![CDATA[ERL_UNLINK]]></c>, then <c><![CDATA[emsg->to]]></c> and <c><![CDATA[emsg->from]]></c>
+          contain the pids of the sender and recipient of the link or unlink.
+          <c><![CDATA[emsg->msg]]></c> is not used in these cases.
+          </p>
+        <p>If <c><![CDATA[type]]></c> contains <c><![CDATA[ERL_EXIT]]></c>, then this
+          indicates that a link has been broken. In this case,
+          <c><![CDATA[emsg->to]]></c> and <c><![CDATA[emsg->from]]></c> contain the pids of the
+          linked processes, and <c><![CDATA[emsg->msg]]></c> contains the reason for
+          the exit.
+          </p>
+        <note>
+          <p>It is the caller's responsibility to release the
+            memory pointed to by <c><![CDATA[emsg->msg]]></c>, <c><![CDATA[emsg->to]]></c> and
+            <c><![CDATA[emsg->from]]></c>.</p>
+        </note>
+        <p>If a <em>tick</em> occurs, i.e., the Erlang node on the
+          other end of the connection has polled this node to see if it
+          is still alive, the function will return <c><![CDATA[ERL_TICK]]></c>
+          indicating that the tick has been received and responded to,
+          but no message will be placed in the buffer. In this case you
+          should call <c><![CDATA[erl_receive_msg()]]></c> again.</p>
+        <p>On success, the function returns <c><![CDATA[ERL_MSG]]></c> and the
+          <c><![CDATA[Emsg]]></c> struct will be initialized as described above, or
+          <c><![CDATA[ERL_TICK]]></c>, in which case no message is returned. On
+          failure, the function returns <c><![CDATA[ERL_ERROR]]></c> and will set
+          <c><![CDATA[erl_errno]]></c> to one of:</p>
+        <taglist>
+          <tag><c><![CDATA[EMSGSIZE]]></c></tag>
+          <item>Buffer too small.</item>
+          <tag><c><![CDATA[ENOMEM]]></c></tag>
+          <item>No more memory available.</item>
+          <tag><c><![CDATA[EIO]]></c></tag>
+          <item>I/O error.</item>
+        </taglist>
+      </desc>
+    </func>
+    <func>
+      <name><ret>int</ret><nametext>erl_xreceive_msg(fd, bufpp, bufsizep, emsg)</nametext></name>
+      <fsummary>Receive and decodes a message</fsummary>
+      <type>
+        <v>int fd;</v>
+        <v>unsigned char **bufpp;</v>
+        <v>int *bufsizep;</v>
+        <v>ErlMessage *emsg;</v>
+      </type>
+      <desc>
+        <p>This function is similar to <c><![CDATA[erl_receive_msg]]></c>. The
+          difference is that <c><![CDATA[erl_xreceive_msg]]></c> expects the buffer to
+          have been allocated by <c><![CDATA[malloc]]></c>, and reallocates it if the received
+          message does not fit into the original buffer. For that reason,
+          both buffer and buffer length are given as pointers - their values
+          may change by the call.
+          </p>
+        <p>On success, the function returns <c><![CDATA[ERL_MSG]]></c> and the
+          <c><![CDATA[Emsg]]></c> struct will be initialized as described above, or
+          <c><![CDATA[ERL_TICK]]></c>, in which case no message is returned. On
+          failure, the function returns <c><![CDATA[ERL_ERROR]]></c> and will set
+          <c><![CDATA[erl_errno]]></c> to one of:</p>
+        <taglist>
+          <tag><c><![CDATA[EMSGSIZE]]></c></tag>
+          <item>Buffer too small.</item>
+          <tag><c><![CDATA[ENOMEM]]></c></tag>
+          <item>No more memory available.</item>
+          <tag><c><![CDATA[EIO]]></c></tag>
+          <item>I/O error.</item>
+        </taglist>
+      </desc>
+    </func>
+    <func>
+      <name><ret>int</ret><nametext>erl_send(fd, to, msg)</nametext></name>
+      <fsummary>Send a message</fsummary>
+      <type>
+        <v>int fd;</v>
+        <v>ETERM *to, *msg;</v>
+      </type>
+      <desc>
+        <p>This function sends an Erlang term to a process.</p>
+        <p><c><![CDATA[fd]]></c> is an open descriptor to an Erlang connection.</p>
+        <p><c><![CDATA[to]]></c> is an Erlang term containing the Pid of the
+          intended recipient of the message.</p>
+        <p><c><![CDATA[msg]]></c> is the Erlang term to be sent.</p>
+        <p>The function returns 1 if successful, otherwise 0 --- in
+          which case it will set <c><![CDATA[erl_errno]]></c> to one of:</p>
+        <taglist>
+          <tag><c><![CDATA[EINVAL]]></c></tag>
+          <item>Invalid argument: <c><![CDATA[to]]></c> is not a valid Erlang pid.</item>
+          <tag><c><![CDATA[ENOMEM]]></c></tag>
+          <item>No more memory available.</item>
+          <tag><c><![CDATA[EIO]]></c></tag>
+          <item>I/O error.</item>
+        </taglist>
+      </desc>
+    </func>
+    <func>
+      <name><ret>int</ret><nametext>erl_reg_send(fd, to, msg)</nametext></name>
+      <fsummary>Send a message to a registered name</fsummary>
+      <type>
+        <v>int fd;</v>
+        <v>char *to;</v>
+        <v>ETERM *msg;</v>
+      </type>
+      <desc>
+        <p>This function sends an Erlang term to a registered process.</p>
+        <p><c><![CDATA[fd]]></c> is an open descriptor to an Erlang connection.</p>
+        <p><c><![CDATA[to]]></c> is a string containing the registered name of
+          the intended recipient of the message.</p>
+        <p><c><![CDATA[msg]]></c> is the Erlang term to be sent.</p>
+        <p>The function returns 1 if successful, otherwise 0 --- in
+          which case it will set <c><![CDATA[erl_errno]]></c> to one of:</p>
+        <taglist>
+          <tag><c><![CDATA[ENOMEM]]></c></tag>
+          <item>No more memory available.</item>
+          <tag><c><![CDATA[EIO]]></c></tag>
+          <item>I/O error.</item>
+        </taglist>
+      </desc>
+    </func>
+    <func>
+      <name><ret>ETERM *</ret><nametext>erl_rpc(fd, mod, fun, args)</nametext></name>
+      <name><ret>int</ret><nametext>erl_rpc_to(fd, mod, fun, args)</nametext></name>
+      <name><ret>int</ret><nametext>erl_rpc_from(fd, timeout, emsg)</nametext></name>
+      <fsummary>Remote Procedure Call</fsummary>
+      <type>
+        <v>int fd, timeout;</v>
+        <v>char *mod, *fun;</v>
+        <v>ETERM *args;</v>
+        <v>ErlMessage *emsg;</v>
+      </type>
+      <desc>
+        <p>These functions support calling Erlang functions on remote nodes.
+          <c><![CDATA[erl_rpc_to()]]></c> sends an rpc request to a remote node and
+          <c><![CDATA[erl_rpc_from()]]></c> receives the results of such a call.
+          <c><![CDATA[erl_rpc()]]></c> combines the functionality of these two functions
+          by sending an rpc request and waiting for the results. See also
+          <c><![CDATA[rpc:call/4]]></c>. </p>
+        <p><c><![CDATA[fd]]></c> is an open descriptor to an Erlang connection.</p>
+        <p><c><![CDATA[timeout]]></c> is the maximum time (in ms) to wait for
+          results. Specify <c><![CDATA[ERL_NO_TIMEOUT]]></c> to wait forever.
+          When erl_rpc() calls erl_rpc_from(), the call will never
+          timeout.</p>
+        <p><c><![CDATA[mod]]></c> is the name of the module containing the function
+          to be run on the remote node.</p>
+        <p><c><![CDATA[fun]]></c> is the name of the function to run.</p>
+        <p><c><![CDATA[args]]></c> is an Erlang list, containing the arguments to be
+          passed to the function. </p>
+        <p><c><![CDATA[emsg]]></c> is a message containing the result of the
+          function call.</p>
+        <p>The actual message returned by the rpc server
+          is a 2-tuple <c><![CDATA[{rex,Reply}]]></c>. If you are using
+          <c><![CDATA[erl_rpc_from()]]></c> in your code then this is the message you
+          will need to parse. If you are using <c><![CDATA[erl_rpc()]]></c> then the
+          tuple itself is parsed for you, and the message returned to your
+          program is the erlang term containing <c><![CDATA[Reply]]></c> only. Replies
+          to rpc requests are always ERL_SEND messages.
+          </p>
+        <note>
+          <p>It is the caller's responsibility to free the returned
+            <c><![CDATA[ETERM]]></c> structure as well as the memory pointed to by
+            <c><![CDATA[emsg->msg]]></c> and <c><![CDATA[emsg->to]]></c>.  </p>
+        </note>
+        <p><c><![CDATA[erl_rpc()]]></c> returns the remote function's return value (or
+          <c><![CDATA[NULL]]></c> if it failed). <c><![CDATA[erl_rpc_to()]]></c> returns 0 on
+          success, and a negative number on failure. <c><![CDATA[erl_rcp_from()]]></c>
+          returns <c><![CDATA[ERL_MSG]]></c> when successful (with <c><![CDATA[Emsg]]></c> now
+          containing the reply tuple), and one of <c><![CDATA[ERL_TICK]]></c>,
+          <c><![CDATA[ERL_TIMEOUT]]></c> and <c><![CDATA[ERL_ERROR]]></c> otherwise. When failing,
+          all three functions set <c><![CDATA[erl_errno]]></c> to one of:</p>
+        <taglist>
+          <tag><c><![CDATA[ENOMEM]]></c></tag>
+          <item>No more memory available.</item>
+          <tag><c><![CDATA[EIO]]></c></tag>
+          <item>I/O error.</item>
+          <tag><c><![CDATA[ETIMEDOUT]]></c></tag>
+          <item>Timeout expired.</item>
+          <tag><c><![CDATA[EAGAIN]]></c></tag>
+          <item>Temporary error: Try again.</item>
+        </taglist>
+      </desc>
+    </func>
+    <func>
+      <name><ret>int</ret><nametext>erl_publish(port)</nametext></name>
+      <fsummary>Publish a node name</fsummary>
+      <type>
+        <v>int port;</v>
+      </type>
+      <desc>
+        <p>These functions are used by a server process to register
+          with the local name server <em>epmd</em>, thereby allowing
+          other processes to send messages by using the registered name.
+          Before calling either of these functions, the process should
+          have called <c><![CDATA[bind()]]></c> and <c><![CDATA[listen()]]></c> on an open socket.</p>
+        <p><c><![CDATA[port]]></c> is the local name to register, and should be the
+          same as the port number that was previously bound to the socket.</p>
+        <p>To unregister with epmd, simply close the returned
+          descriptor. See also <c><![CDATA[erl_unpublish()]]></c>.
+          </p>
+        <p>On success, the functions return a descriptor connecting the
+          calling process to epmd. On failure, they return -1 and set
+          <c><![CDATA[erl_errno]]></c> to:</p>
+        <taglist>
+          <tag><c><![CDATA[EIO]]></c></tag>
+          <item>I/O error</item>
+        </taglist>
+        <p>Additionally, <c><![CDATA[errno]]></c> values from <c><![CDATA[socket]]></c><em>(2)</em>
+          and <c><![CDATA[connect]]></c><em>(2)</em> system calls may be propagated
+          into <c><![CDATA[erl_errno]]></c>.
+          </p>
+      </desc>
+    </func>
+    <func>
+      <name><ret>int</ret><nametext>erl_accept(listensock, conp)</nametext></name>
+      <fsummary>Accept a connection</fsummary>
+      <type>
+        <v>int listensock;</v>
+        <v>ErlConnect *conp;</v>
+      </type>
+      <desc>
+        <p>This function is used by a server process to accept a
+          connection from a client process.</p>
+        <p><c><![CDATA[listensock]]></c> is an open socket descriptor on which
+          <c><![CDATA[listen()]]></c> has previously been called.</p>
+        <p><c><![CDATA[conp]]></c> is a pointer to an <c><![CDATA[ErlConnect]]></c> struct,
+          described as follows:</p>
+        <code type="none"><![CDATA[
+typedef struct {
+  char ipadr[4];             
+  char nodename[MAXNODELEN];
+} ErlConnect;
+        ]]></code>
+        <p>On success, <c><![CDATA[conp]]></c> is filled in with the address and
+          node name of the connecting client and a file descriptor is
+          returned. On failure, <c><![CDATA[ERL_ERROR]]></c> is returned and
+          <c><![CDATA[erl_errno]]></c> is set to <c><![CDATA[EIO]]></c>.</p>
+      </desc>
+    </func>
+    <func>
+      <name><ret>const char *</ret><nametext>erl_thiscookie()</nametext></name>
+      <name><ret>const char *</ret><nametext>erl_thisnodename()</nametext></name>
+      <name><ret>const char *</ret><nametext>erl_thishostname()</nametext></name>
+      <name><ret>const char *</ret><nametext>erl_thisalivename()</nametext></name>
+      <name><ret>short</ret><nametext>erl_thiscreation()</nametext></name>
+      <fsummary>Retrieve some values</fsummary>
+      <desc>
+        <p>These functions can be used to retrieve information about
+          the C Node. These values are initially set with
+          <c><![CDATA[erl_connect_init()]]></c> or <c><![CDATA[erl_connect_xinit()]]></c>.</p>
+      </desc>
+    </func>
+    <func>
+      <name><ret>int</ret><nametext>erl_unpublish(alive)</nametext></name>
+      <fsummary>Unpublish a node name</fsummary>
+      <type>
+        <v>char *alive;</v>
+      </type>
+      <desc>
+        <p>This function can be called by a process to unregister a
+          specified node name from epmd on the localhost. This may be
+          useful, for example, when epmd has not detected the failure of a
+          node, and will not allow the name to be reused. If you use this
+          function to unregister your own process, be sure to also close
+          the descriptor that was returned by <c><![CDATA[erl_publish()]]></c>.</p>
+        <note>
+          <p>Careless use of this function may have unpredictable
+            results, if the registered node is in fact still running.</p>
+        </note>
+        <p><c><![CDATA[alive]]></c> is the name of the node to unregister, i.e., the
+          first component of the nodename, without the <c><![CDATA[@hostname]]></c>.</p>
+        <p>If the node was successfully unregistered from epmd, the
+          function returns 0. Otherwise, it returns -1 and sets
+          <c><![CDATA[erl_errno]]></c> is to <c><![CDATA[EIO]]></c>.</p>
+      </desc>
+    </func>
+    <func>
+      <name><ret>struct hostent</ret><nametext>*erl_gethostbyname(name)</nametext></name>
+      <name><ret>struct hostent</ret><nametext>*erl_gethostbyaddr(addr, length, type)</nametext></name>
+      <name><ret>struct hostent</ret><nametext>*erl_gethostbyname_r(name, hostp, buffer, buflen, h_errnop)</nametext></name>
+      <name><ret>struct hostent</ret><nametext>*erl_gethostbyaddr_r(addr, length, type, hostp, buffer, buflen, h_errnop)</nametext></name>
+      <fsummary>Name lookup functions</fsummary>
+      <type>
+        <v>const char *name;</v>
+        <v>const char *addr;</v>
+        <v>int length;</v>
+        <v>int type;</v>
+        <v>struct hostent *hostp;</v>
+        <v>char *buffer;</v>
+        <v>int buflen;</v>
+        <v>int *h_errnop;</v>
+      </type>
+      <desc>
+        <p>These are convenience functions for some common name lookup functions.</p>
+      </desc>
+    </func>
+  </funcs>
+
+  <section>
+    <title>Debug Information</title>
+    <p>If a connection attempt fails, the following can be checked:</p>
+    <list type="bulleted">
+      <item><c><![CDATA[erl_errno]]></c></item>
+      <item>that the right cookie was used</item>
+      <item>that <em>epmd</em> is running</item>
+      <item>the remote Erlang node on the other side is running the same
+       version of Erlang as the <c><![CDATA[erl_interface]]></c> library.</item>
+    </list>
+  </section>
+</cref>
+