aboutsummaryrefslogtreecommitdiff
path: root/docs/http.html
diff options
context:
space:
mode:
authorCaleb Maclennan <caleb@alerque.com>2023-11-10 09:12:04 +0300
committerCaleb Maclennan <caleb@alerque.com>2023-11-10 09:12:04 +0300
commit5c4fc93d5f4137bf4c22ddf1a048c907a4a26727 (patch)
treea9a68e1f6a9c3bfe2b64fa1c3a4098865b7d3b5d /docs/http.html
parentccef3bc4e2aa6ee5b997a80aabb58f4ff0b0e98f (diff)
parent43a97b7f0053313b43906371dbdc226271e6c8ab (diff)
downloadluasocket-hjelmeland-patch-1.tar.gz
luasocket-hjelmeland-patch-1.tar.bz2
luasocket-hjelmeland-patch-1.zip
Merge branch 'master' into hjelmeland-patch-1hjelmeland-patch-1
Diffstat (limited to 'docs/http.html')
-rw-r--r--docs/http.html339
1 files changed, 339 insertions, 0 deletions
diff --git a/docs/http.html b/docs/http.html
new file mode 100644
index 0000000..52b8a30
--- /dev/null
+++ b/docs/http.html
@@ -0,0 +1,339 @@
1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
2 "http://www.w3.org/TR/html4/strict.dtd">
3<html>
4
5<head>
6<meta name="description" content="LuaSocket: HTTP support">
7<meta name="keywords" content="Lua, HTTP, Library, WWW, Browser, Network, Support">
8<title>LuaSocket: HTTP support</title>
9<link rel="stylesheet" href="reference.css" type="text/css">
10</head>
11
12<body>
13
14<!-- header ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
15
16<div class="header">
17<hr>
18<center>
19<table summary="LuaSocket logo">
20<tr><td align="center"><a href="http://www.lua.org">
21<img width="128" height="128" border="0" alt="LuaSocket" src="luasocket.png">
22</a></td></tr>
23<tr><td align="center" valign="top">Network support for the Lua language
24</td></tr>
25</table>
26<p class="bar">
27<a href="index.html">home</a> &middot;
28<a href="index.html#download">download</a> &middot;
29<a href="introduction.html">introduction</a> &middot;
30<a href="introduction.html">introduction</a> &middot;
31<a href="reference.html">reference</a>
32</p>
33</center>
34<hr>
35</div>
36
37<!-- http +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
38
39<h2 id="http">HTTP</h2>
40
41<p>
42HTTP (Hyper Text Transfer Protocol) is the protocol used to exchange
43information between web-browsers and servers. The <tt>http</tt>
44namespace offers full support for the client side of the HTTP
45protocol (i.e.,
46the facilities that would be used by a web-browser implementation). The
47implementation conforms to the HTTP/1.1 standard,
48<a href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616</a>.
49</p>
50
51<p>
52The module exports functions that provide HTTP functionality in different
53levels of abstraction. From the simple
54string oriented requests, through generic
55<a href="http://lua-users.org/wiki/FiltersSourcesAndSinks">LTN12</a> based, down to even lower-level if you bother to look through the source code.
56</p>
57
58<p>
59To obtain the <tt>http</tt> namespace, run:
60</p>
61
62<pre class="example">
63-- loads the HTTP module and any libraries it requires
64local http = require("socket.http")
65</pre>
66
67<p>
68URLs must conform to
69<a href="http://www.ietf.org/rfc/rfc1738.txt">RFC 1738</a>,
70that is, an URL is a string in the form:
71</p>
72
73<blockquote>
74<pre>
75[http://][&lt;user&gt;[:&lt;password&gt;]@]&lt;host&gt;[:&lt;port&gt;][/&lt;path&gt;]
76</pre>
77</blockquote>
78
79<p>
80MIME headers are represented as a Lua table in the form:
81</p>
82
83<blockquote>
84<table summary="MIME headers in Lua table">
85<tr><td><tt>
86headers = {<br>
87&nbsp;&nbsp;field-1-name = <i>field-1-value</i>,<br>
88&nbsp;&nbsp;field-2-name = <i>field-2-value</i>,<br>
89&nbsp;&nbsp;field-3-name = <i>field-3-value</i>,<br>
90&nbsp;&nbsp;...<br>
91&nbsp;&nbsp;field-n-name = <i>field-n-value</i><br>
92}
93</tt></td></tr>
94</table>
95</blockquote>
96
97<p>
98Field names are case insensitive (as specified by the standard) and all
99functions work with lowercase field names (but see
100<a href="socket.html#headers.canonic"><tt>socket.headers.canonic</tt></a>).
101Field values are left unmodified.
102</p>
103
104<p class="note">
105Note: MIME headers are independent of order. Therefore, there is no problem
106in representing them in a Lua table.
107</p>
108
109<p>
110The following constants can be set to control the default behavior of
111the HTTP module:
112</p>
113
114<ul>
115<li> <tt>PROXY</tt>: default proxy used for connections;</li>
116<li> <tt>TIMEOUT</tt>: sets the timeout for all I/O operations;</li>
117<li> <tt>USERAGENT</tt>: default user agent reported to server.</li>
118</ul>
119
120<p class="note">
121Note: These constants are global. Changing them will also
122change the behavior other code that might be using LuaSocket.
123</p>
124
125<!-- http.request ++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
126
127<p class="name" id="request">
128http.<b>request(</b>url [, body]<b>)</b><br>
129http.<b>request{</b><br>
130&nbsp;&nbsp;url = <i>string</i>,<br>
131&nbsp;&nbsp;[sink = <i>LTN12 sink</i>,]<br>
132&nbsp;&nbsp;[method = <i>string</i>,]<br>
133&nbsp;&nbsp;[headers = <i>header-table</i>,]<br>
134&nbsp;&nbsp;[source = <i>LTN12 source</i>],<br>
135&nbsp;&nbsp;[step = <i>LTN12 pump step</i>,]<br>
136&nbsp;&nbsp;[proxy = <i>string</i>,]<br>
137&nbsp;&nbsp;[redirect = <i>boolean</i>,]<br>
138&nbsp;&nbsp;[create = <i>function</i>,]<br>
139&nbsp;&nbsp;[maxredirects = <i>number</i>]<br>
140<b>}</b>
141</p>
142
143<p class="description">
144The request function has two forms. The simple form downloads
145a URL using the <tt>GET</tt> or <tt>POST</tt> method and is based
146on strings. The generic form performs any HTTP method and is
147<a href="http://lua-users.org/wiki/FiltersSourcesAndSinks">LTN12</a> based.
148</p>
149
150<p class="parameters">
151If the first argument of the <tt>request</tt> function is a string, it
152should be an <tt>url</tt>. In that case, if a <tt>body</tt>
153is provided as a string, the function will perform a <tt>POST</tt> method
154in the <tt>url</tt>. Otherwise, it performs a <tt>GET</tt> in the
155<tt>url</tt>
156</p>
157
158<p class="parameters">
159If the first argument is instead a table, the most important fields are
160the <tt>url</tt> and the <em>simple</em>
161<a href="http://lua-users.org/wiki/FiltersSourcesAndSinks">LTN12</a>
162<tt>sink</tt> that will receive the downloaded content.
163Any part of the <tt>url</tt> can be overridden by including
164the appropriate field in the request table.
165If authentication information is provided, the function
166uses the Basic Authentication Scheme (see <a href="#authentication">note</a>)
167to retrieve the document. If <tt>sink</tt> is <tt><b>nil</b></tt>, the
168function discards the downloaded data. The optional parameters are the
169following:
170</p>
171<ul>
172<li><tt>method</tt>: The HTTP request method. Defaults to "GET";</li>
173<li><tt>headers</tt>: Any additional HTTP headers to send with the request;</li>
174<li><tt>source</tt>: <em>simple</em>
175<a href="http://lua-users.org/wiki/FiltersSourcesAndSinks">LTN12</a>
176source to provide the request body. If there
177is a body, you need to provide an appropriate "<tt>content-length</tt>"
178request header field, or the function will attempt to send the body as
179"<tt>chunked</tt>" (something few servers support). Defaults to the empty source;</li>
180<li><tt>step</tt>:
181<a href="http://lua-users.org/wiki/FiltersSourcesAndSinks">LTN12</a>
182pump step function used to move data.
183Defaults to the LTN12 <tt>pump.step</tt> function.</li>
184<li><tt>proxy</tt>: The URL of a proxy server to use. Defaults to no proxy;</li>
185<li><tt>redirect</tt>: Set to <tt><b>false</b></tt> to prevent the
186function from automatically following 301 or 302 server redirect messages;</li>
187<li><tt>create</tt>: An optional function to be used instead of
188<a href="tcp.html#socket.tcp"><tt>socket.tcp</tt></a> when the communications socket is created.</li>
189<li><tt>maxredirects</tt>: An optional number specifying the maximum number of
190 redirects to follow. Defaults to <tt>5</tt> if not specified. A boolean
191 <tt>false</tt> value means no maximum (unlimited).</li>
192</ul>
193
194<p class="return">
195In case of failure, the function returns <tt><b>nil</b></tt> followed by an
196error message. If successful, the simple form returns the response
197body as a string, followed by the response status code, the response
198headers and the response status line. The generic function returns the same
199information, except the first return value is just the number 1 (the body
200goes to the <tt>sink</tt>).
201</p>
202
203<p class="return">
204Even when the server fails to provide the contents of the requested URL (URL not found, for example),
205it usually returns a message body (a web page informing the
206URL was not found or some other useless page). To make sure the
207operation was successful, check the returned status <tt>code</tt>. For
208a list of the possible values and their meanings, refer to <a
209href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616</a>.
210</p>
211
212<p class="description">
213Here are a few examples with the simple interface:
214</p>
215
216<pre class="example">
217-- load the http module
218local io = require("io")
219local http = require("socket.http")
220local ltn12 = require("ltn12")
221
222-- connect to server "www.cs.princeton.edu" and retrieves this manual
223-- file from "~diego/professional/luasocket/http.html" and print it to stdout
224http.request{
225 url = "http://www.cs.princeton.edu/~diego/professional/luasocket/http.html",
226 sink = ltn12.sink.file(io.stdout)
227}
228
229-- connect to server "www.example.com" and tries to retrieve
230-- "/private/index.html". Fails because authentication is needed.
231b, c, h = http.request("http://www.example.com/private/index.html")
232-- b returns some useless page telling about the denied access,
233-- h returns authentication information
234-- and c returns with value 401 (Authentication Required)
235
236-- tries to connect to server "wrong.host" to retrieve "/"
237-- and fails because the host does not exist.
238r, e = http.request("http://wrong.host/")
239-- r is nil, and e returns with value "host not found"
240</pre>
241
242<p class="description">
243And here is an example using the generic interface:
244</p>
245
246<pre class="example">
247-- load the http module
248http = require("socket.http")
249
250-- Requests information about a document, without downloading it.
251-- Useful, for example, if you want to display a download gauge and need
252-- to know the size of the document in advance
253r, c, h = http.request {
254 method = "HEAD",
255 url = "http://www.tecgraf.puc-rio.br/~diego"
256}
257-- r is 1, c is 200, and h would return the following headers:
258-- h = {
259-- date = "Tue, 18 Sep 2001 20:42:21 GMT",
260-- server = "Apache/1.3.12 (Unix) (Red Hat/Linux)",
261-- ["last-modified"] = "Wed, 05 Sep 2001 06:11:20 GMT",
262-- ["content-length"] = 15652,
263-- ["connection"] = "close",
264-- ["content-Type"] = "text/html"
265-- }
266</pre>
267
268<p class="note" id="post">
269Note: When sending a POST request, simple interface adds a
270"<tt>Content-type: application/x-www-form-urlencoded</tt>"
271header to the request. This is the type used by
272HTML forms. If you need another type, use the generic
273interface.
274</p>
275
276<p class="note" id="authentication">
277Note: Some URLs are protected by their
278servers from anonymous download. For those URLs, the server must receive
279some sort of authentication along with the request or it will deny
280download and return status "401&nbsp;Authentication Required".
281</p>
282
283<p class="note">
284The HTTP/1.1 standard defines two authentication methods: the Basic
285Authentication Scheme and the Digest Authentication Scheme, both
286explained in detail in
287<a href="http://www.ietf.org/rfc/rfc2068.txt">RFC 2068</a>.
288</p>
289
290<p class="note">The Basic Authentication Scheme sends
291<tt>&lt;user&gt;</tt> and
292<tt>&lt;password&gt;</tt> unencrypted to the server and is therefore
293considered unsafe. Unfortunately, by the time of this implementation,
294the wide majority of servers and browsers support the Basic Scheme only.
295Therefore, this is the method used by the toolkit whenever
296authentication is required.
297</p>
298
299<pre class="example">
300-- load required modules
301http = require("socket.http")
302mime = require("mime")
303
304-- Connect to server "www.example.com" and tries to retrieve
305-- "/private/index.html", using the provided name and password to
306-- authenticate the request
307b, c, h = http.request("http://fulano:silva@www.example.com/private/index.html")
308
309-- Alternatively, one could fill the appropriate header and authenticate
310-- the request directly.
311r, c = http.request {
312 url = "http://www.example.com/private/index.html",
313 headers = { authorization = "Basic " .. (mime.b64("fulano:silva")) }
314}
315</pre>
316
317<!-- footer +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
318
319<div class="footer">
320<hr>
321<center>
322<p class="bar">
323<a href="index.html">home</a> &middot;
324<a href="index.html#download">download</a> &middot;
325<a href="installation.html">installation</a> &middot;
326<a href="introduction.html">introduction</a> &middot;
327<a href="reference.html">reference</a>
328</p>
329<p>
330<small>
331Last modified by Eric Westbrook on <br>
332Sat Feb 23 19:09:42 UTC 2019
333</small>
334</p>
335</center>
336</div>
337
338</body>
339</html>
generated by cgit v1.2.3-55-g6feb (git 2.39.1) at 2025-03-21 13:12:54 +0000