1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
|
<?xml version="1.0" encoding="latin1" ?>
<!DOCTYPE erlref SYSTEM "erlref.dtd">
<erlref>
<header>
<copyright>
<year>1997</year><year>2011</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>gen_udp</title>
<prepared>[email protected]</prepared>
<docno></docno>
<date>1997-12-03</date>
<rev>A</rev>
</header>
<module>gen_udp</module>
<modulesummary>Interface to UDP sockets</modulesummary>
<description>
<p>The <c>gen_udp</c> module provides functions for communicating
with sockets using the UDP protocol.</p>
</description>
<datatypes>
<datatype>
<name name="option"/>
</datatype>
<datatype>
<name name="option_name"/>
</datatype>
<datatype>
<name><marker id="type-socket">socket()</marker></name>
<desc>
<p>As returned by open/1,2.</p>
</desc>
</datatype>
</datatypes>
<funcs>
<func>
<name name="open" arity="1"/>
<name name="open" arity="2"/>
<fsummary>Associate a UDP port number with the process calling it</fsummary>
<desc>
<p>Associates a UDP port number (<c><anno>Port</anno></c>) with the calling
process.</p>
<p>The available options are:</p>
<taglist>
<tag><c>list</c></tag>
<item>
<p>Received <c>Packet</c> is delivered as a list.</p>
</item>
<tag><c>binary</c></tag>
<item>
<p>Received <c>Packet</c> is delivered as a binary.</p>
</item>
<tag><c>{ip, ip_address()}</c></tag>
<item>
<p>If the host has several network interfaces, this option
specifies which one to use.</p>
</item>
<tag><c>{fd, integer() >= 0}</c></tag>
<item>
<p>If a socket has somehow been opened without using
<c>gen_udp</c>, use this option to pass the file
descriptor for it.</p>
</item>
<tag><c>inet6</c></tag>
<item>
<p>Set up the socket for IPv6.</p>
</item>
<tag><c>inet</c></tag>
<item>
<p>Set up the socket for IPv4.</p>
</item>
<tag><c>Opt</c></tag>
<item>
<p>See
<seealso marker="inet#setopts/2">inet:setopts/2</seealso>.</p>
</item>
</taglist>
<p>The returned socket <c><anno>Socket</anno></c> is used to send packets
from this port with <c>send/4</c>. When UDP packets arrive at
the opened port, they are delivered as messages:</p>
<code type="none">
{udp, Socket, IP, InPortNo, Packet}</code>
<p>Note that arriving UDP packets that are longer than
the receive buffer option specifies, might be truncated
without warning.</p>
<p><c>IP</c> and <c>InPortNo</c> define the address from which
<c>Packet</c> came. <c>Packet</c> is a list of bytes if
the option <c>list</c> was specified. <c>Packet</c> is a
binary if the option <c>binary</c> was specified.</p>
<p>Default value for the receive buffer option is
<c>{recbuf, 8192}</c>.</p>
<p>If <c><anno>Port</anno> == 0</c>, the underlying OS assigns a free UDP
port, use <c>inet:port/1</c> to retrieve it.</p>
</desc>
</func>
<func>
<name name="send" arity="4"/>
<fsummary>Send a packet</fsummary>
<desc>
<p>Sends a packet to the specified address and port.
The <c><anno>Address</anno></c> argument can be either a hostname, or an
IP address.</p>
</desc>
</func>
<func>
<name name="recv" arity="2"/>
<name name="recv" arity="3"/>
<fsummary>Receive a packet from a passive socket</fsummary>
<desc>
<p>This function receives a packet from a socket in passive
mode.</p>
<p>The optional <c><anno>Timeout</anno></c> parameter specifies a timeout in
milliseconds. The default value is <c>infinity</c>.</p>
</desc>
</func>
<func>
<name name="controlling_process" arity="2"/>
<fsummary>Change controlling process of a socket</fsummary>
<desc>
<p>Assigns a new controlling process <c><anno>Pid</anno></c> to
<c><anno>Socket</anno></c>. The controlling process is the process which
receives messages from the socket. If called by any other
process than the current controlling process,
<c>{error, not_owner}</c> is returned.</p>
</desc>
</func>
<func>
<name name="close" arity="1"/>
<fsummary>Close a UDP socket</fsummary>
<desc>
<p>Closes a UDP socket.</p>
</desc>
</func>
</funcs>
</erlref>
|
