Mercurial > luasocket

annotate doc/introduction.html @ 0:4b915342e2a8

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
LuaSocket 2.0.2 + CMake build description.
author Eric Wing <ewing . public |-at-| gmail . com>
date Tue, 26 Aug 2008 18:40:01 -0700
parents
children
rev   line source
0
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
2 "http://www.w3.org/TR/html4/strict.dtd">
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
3 <html>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
4
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
5 <head>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
6 <meta name="description" content="LuaSocket: Introduction to the core">
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
7 <meta name="keywords" content="Lua, LuaSocket, TCP, UDP, Network,
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
8 Library, Support">
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
9 <title>LuaSocket: Introduction to the core</title>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
10 <link rel="stylesheet" href="reference.css" type="text/css">
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
11 </head>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
12
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
13 <body>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
14
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
15 <!-- header +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
16
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
17 <div class=header>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
18 <hr>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
19 <center>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
20 <table summary="LuaSocket logo">
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
21 <tr><td align=center><a href="http://www.lua.org">
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
22 <img width=128 height=128 border=0 alt="LuaSocket" src="luasocket.png">
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
23 </a></td></tr>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
24 <tr><td align=center valign=top>Network support for the Lua language
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
25 </td></tr>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
26 </table>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
27 <p class=bar>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
28 <a href="home.html">home</a> &middot;
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
29 <a href="home.html#download">download</a> &middot;
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
30 <a href="installation.html">installation</a> &middot;
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
31 <a href="introduction.html">introduction</a> &middot;
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
32 <a href="reference.html">reference</a>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
33 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
34 </center>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
35 <hr>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
36 </div>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
37
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
38 <!-- introduction +++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
39
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
40 <h2>Introduction</h2>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
41
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
42 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
43 LuaSocket is a <a href="http://www.lua.org">Lua</a> extension library
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
44 that is composed by two parts: a C core that provides support for the TCP
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
45 and UDP transport layers, and a set of Lua modules that add support for
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
46 the SMTP (sending e-mails), HTTP (WWW access) and FTP (uploading and
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
47 downloading files) protocols and other functionality commonly needed by
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
48 applications that deal with the Internet. This introduction is about the C
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
49 core.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
50 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
51
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
52 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
53 Communication in LuaSocket is performed via I/O objects. These can
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
54 represent different network domains. Currently, support is provided for TCP
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
55 and UDP, but nothing prevents other developers from implementing SSL, Local
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
56 Domain, Pipes, File Descriptors etc. I/O objects provide a standard
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
57 interface to I/O across different domains and operating systems.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
58 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
59
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
60 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
61 The API design had two goals in mind. First, users
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
62 experienced with the C API to sockets should feel comfortable using LuaSocket.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
63 Second, the simplicity and the feel of the Lua language should be
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
64 preserved. To achieve these goals, the LuaSocket API keeps the function names and semantics the C API whenever possible, but their usage in Lua has been greatly simplified.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
65 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
66
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
67
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
68 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
69 One of the simplifications is the receive pattern capability.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
70 Applications can read data from stream domains (such as TCP)
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
71 line by line, block by block, or until the connection is closed.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
72 All I/O reads are buffered and the performance differences between
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
73 different receive patterns are negligible.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
74 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
75
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
76 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
77 Another advantage is the flexible timeout control
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
78 mechanism. As in C, all I/O operations are blocking by default. For
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
79 example, the <a href=tcp.html#send><tt>send</tt></a>,
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
80 <a href=tcp.html#receive><tt>receive</tt></a> and
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
81 <a href=tcp.html#accept><tt>accept</tt></a> methods
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
82 of the TCP domain will block the caller application until
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
83 the operation is completed (if ever!). However, with a call to the
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
84 <a href=tcp.html#settimeout><tt>settimeout</tt></a>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
85 method, an application can specify upper limits on
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
86 the time it can be blocked by LuaSocket (the "<tt>total</tt>" timeout), on
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
87 the time LuaSocket can internally be blocked by any OS call (the
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
88 "<tt>block</tt>" timeout) or a combination of the two. Each LuaSocket
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
89 call might perform several OS calls, so that the two timeout values are
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
90 <em>not</em> equivalent.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
91 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
92
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
93 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
94 Finally, the host name resolution is transparent, meaning that most
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
95 functions and methods accept both IP addresses and host names. In case a
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
96 host name is given, the library queries the system's resolver and
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
97 tries the main IP address returned. Note that direct use of IP addresses
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
98 is more efficient, of course. The
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
99 <a href=dns.html#toip><tt>toip</tt></a>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
100 and <a href=dns.html#tohostname><tt>tohostname</tt></a>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
101 functions from the DNS module are provided to convert between host names and IP addresses.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
102 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
103
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
104 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
105 Together, these changes make network programming in LuaSocket much simpler
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
106 than it is in C, as the following sections will show.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
107 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
108
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
109 <!-- tcp ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
110
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
111 <h3 id=tcp>TCP</h3>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
112
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
113 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
114 TCP (Transfer Control Protocol) is reliable stream protocol. In other
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
115 words, applications communicating through TCP can send and receive data as
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
116 an error free stream of bytes. Data is split in one end and
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
117 reassembled transparently on the other end. There are no boundaries in
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
118 the data transfers. The library allows users to read data from the
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
119 sockets in several different granularities: patterns are available for
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
120 lines, arbitrary sized blocks or "read up to connection closed", all with
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
121 good performance.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
122 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
123
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
124 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
125 The library distinguishes three types of TCP sockets: <em>master</em>,
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
126 <em>client</em> and <em>server</em> sockets.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
127 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
128
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
129 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
130 Master sockets are newly created TCP sockets returned by the function
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
131 <a href=tcp.html#tcp><tt>socket.tcp</tt></a>. A master socket is
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
132 transformed into a server socket
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
133 after it is associated with a <em>local</em> address by a call to the
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
134 <a href=tcp.html#bind><tt>bind</tt></a> method followed by a call to the
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
135 <a href=tcp.html#listen><tt>listen</tt></a>. Conversely, a master socket
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
136 can be changed into a client socket with the method
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
137 <a href=tcp.html#connect><tt>connect</tt></a>,
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
138 which associates it with a <em>remote</em> address.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
139 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
140
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
141 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
142 On server sockets, applications can use the
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
143 <a href=tcp.html#accept><tt>accept</tt></a> method
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
144 to wait for a client connection. Once a connection is established, a
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
145 client socket object is returned representing this connection. The
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
146 other methods available for server socket objects are
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
147 <a href=tcp.html#getsockname><tt>getsockname</tt></a>,
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
148 <a href=tcp.html#setoption><tt>setoption</tt></a>,
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
149 <a href=tcp.html#settimeout><tt>settimeout</tt></a>, and
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
150 <a href=tcp.html#close><tt>close</tt></a>.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
151 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
152
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
153 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
154 Client sockets are used to exchange data between two applications over
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
155 the Internet. Applications can call the methods
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
156 <a href=tcp.html#send><tt>send</tt></a> and
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
157 <a href=tcp.html#receive><tt>receive</tt></a>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
158 to send and receive data. The other methods
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
159 available for client socket objects are
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
160 <a href=tcp.html#getsockname><tt>getsockname</tt></a>,
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
161 <a href=tcp.html#getpeername><tt>getpeername</tt></a>,
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
162 <a href=tcp.html#setoption><tt>setoption</tt></a>,
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
163 <a href=tcp.html#settimeout><tt>settimeout</tt></a>,
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
164 <a href=tcp.html#shutdown><tt>shutdown</tt></a>, and
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
165 <a href=tcp.html#close><tt>close</tt></a>.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
166 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
167
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
168 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
169 Example:
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
170 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
171 <blockquote>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
172 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
173 A simple echo server, using LuaSocket. The program binds to an ephemeral
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
174 port (one that is chosen by the operating system) on the local host and
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
175 awaits client connections on that port. When a connection is established,
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
176 the program reads a line from the remote end and sends it back, closing
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
177 the connection immediately. You can test it using the telnet
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
178 program.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
179 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
180
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
181 <pre class=example>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
182 -- load namespace
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
183 local socket = require("socket")
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
184 -- create a TCP socket and bind it to the local host, at any port
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
185 local server = assert(socket.bind("*", 0))
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
186 -- find out which port the OS chose for us
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
187 local ip, port = server:getsockname()
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
188 -- print a message informing what's up
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
189 print("Please telnet to localhost on port " .. port)
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
190 print("After connecting, you have 10s to enter a line to be echoed")
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
191 -- loop forever waiting for clients
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
192 while 1 do
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
193 -- wait for a connection from any client
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
194 local client = server:accept()
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
195 -- make sure we don't block waiting for this client's line
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
196 client:settimeout(10)
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
197 -- receive the line
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
198 local line, err = client:receive()
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
199 -- if there was no error, send it back to the client
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
200 if not err then client:send(line .. "\n") end
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
201 -- done with client, close the object
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
202 client:close()
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
203 end
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
204 </pre>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
205 </blockquote>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
206
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
207 <!-- udp ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
208
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
209 <h3 id=udp>UDP</h3>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
210
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
211 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
212 UDP (User Datagram Protocol) is a non-reliable datagram protocol. In
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
213 other words, applications communicating through UDP send and receive
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
214 data as independent blocks, which are not guaranteed to reach the other
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
215 end. Even when they do reach the other end, they are not guaranteed to be
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
216 error free. Data transfers are atomic, one datagram at a time. Reading
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
217 only part of a datagram discards the rest, so that the following read
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
218 operation will act on the next datagram. The advantages are in
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
219 simplicity (no connection setup) and performance (no error checking or
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
220 error correction).
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
221 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
222
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
223 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
224 Note that although no guarantees are made, these days
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
225 networks are so good that, under normal circumstances, few errors
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
226 happen in practice.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
227 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
228
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
229 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
230 An UDP socket object is created by the
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
231 <a href=udp.html#udp><tt>socket.udp</tt></a> function. UDP
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
232 sockets do not need to be connected before use. The method
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
233 <a href=udp.html#sendto><tt>sendto</tt></a>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
234 can be used immediately after creation to
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
235 send a datagram to IP address and port. Host names are not allowed
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
236 because performing name resolution for each packet would be forbiddingly
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
237 slow. Methods
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
238 <a href=udp.html#receive><tt>receive</tt></a> and
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
239 <a href=udp.html#receivefrom><tt>receivefrom</tt></a>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
240 can be used to retrieve datagrams, the latter returning the IP and port of
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
241 the sender as extra return values (thus being slightly less
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
242 efficient).
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
243 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
244
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
245 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
246 When communication is performed repeatedly with a single peer, an
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
247 application should call the
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
248 <a href=udp.html#setpeername><tt>setpeername</tt></a> method to specify a
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
249 permanent partner. Methods
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
250 <a href=udp.html#sendto><tt>sendto</tt></a> and
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
251 <a href=udp.html#receivefrom><tt>receivefrom</tt></a>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
252 can no longer be used, but the method
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
253 <a href=udp.html#send><tt>send</tt></a> can be used to send data
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
254 directly to the peer, and the method
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
255 <a href=udp.html#receive><tt>receive</tt></a>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
256 will only return datagrams originating
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
257 from that peer. There is about 30% performance gain due to this practice.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
258 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
259
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
260 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
261 To associate an UDP socket with a local address, an application calls the
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
262 <a href=udp.html#setsockname><tt>setsockname</tt></a>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
263 method <em>before</em> sending any datagrams. Otherwise, the socket is
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
264 automatically bound to an ephemeral address before the first data
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
265 transmission and once bound the local address cannot be changed.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
266 The other methods available for UDP sockets are
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
267 <a href=udp.html#getpeername><tt>getpeername</tt></a>,
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
268 <a href=udp.html#getsockname><tt>getsockname</tt></a>,
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
269 <a href=udp.html#settimeout><tt>settimeout</tt></a>,
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
270 <a href=udp.html#setoption><tt>setoption</tt></a> and
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
271 <a href=udp.html#close><tt>close</tt></a>.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
272 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
273
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
274 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
275 Example:
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
276 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
277 <blockquote>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
278 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
279 A simple daytime client, using LuaSocket. The program connects to a remote
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
280 server and tries to retrieve the daytime, printing the answer it got or an
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
281 error message.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
282 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
283
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
284 <pre class=example>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
285 -- change here to the host an port you want to contact
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
286 local host, port = "localhost", 13
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
287 -- load namespace
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
288 local socket = require("socket")
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
289 -- convert host name to ip address
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
290 local ip = assert(socket.dns.toip(host))
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
291 -- create a new UDP object
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
292 local udp = assert(socket.udp())
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
293 -- contact daytime host
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
294 assert(udp:sendto("anything", ip, port))
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
295 -- retrieve the answer and print results
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
296 io.write(assert(udp:receive()))
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
297 </pre>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
298 </blockquote>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
299
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
300 <!-- More +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
301
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
302 <h3 id=more>Support modules</h3>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
303
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
304 <p> Although not covered in the introduction, LuaSocket offers
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
305 much more than TCP and UDP functionality. As the library
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
306 evolved, support for <a href=http.html>HTTP</a>, <a href=ftp.html>FTP</a>,
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
307 and <a href=smtp.html>SMTP</a> were built on top of these. These modules
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
308 and many others are covered by the <a href=reference.html>reference manual</a>.
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
309 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
310
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
311 <!-- footer +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
312
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
313 <div class=footer>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
314 <hr>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
315 <center>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
316 <p class=bar>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
317 <a href="home.html">home</a> &middot;
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
318 <a href="home.html#down">download</a> &middot;
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
319 <a href="installation.html">installation</a> &middot;
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
320 <a href="introduction.html">introduction</a> &middot;
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
321 <a href="reference.html">reference</a>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
322 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
323 <p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
324 <small>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
325 Last modified by Diego Nehab on <br>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
326 Thu Apr 20 00:25:36 EDT 2006
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
327 </small>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
328 </p>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
329 </center>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
330 </div>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
331
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
332 </body>
4b915342e2a8 LuaSocket 2.0.2 + CMake build description.
Eric Wing <ewing . public |-at-| gmail . com>
parents:
diff changeset
333 </html>