1-- $NetBSD: printenv.lua,v 1.5 2021/02/28 16:10:00 rillig Exp $
2
3-- this small Lua script demonstrates the use of Lua in (bozo)httpd
4-- it will simply output the "environment"
5
6-- Keep in mind that bozohttpd forks for each request when started in
7-- daemon mode, you can set global variables here, but they will have
8-- the same value on each invocation.  You can not keep state between
9-- two calls.
10
11-- You can test this example by running the following command:
12-- /usr/libexec/httpd -b -f -I 8080 -L test printenv.lua .
13-- and then navigate to: http://127.0.0.1:8080/test/printenv
14
15local httpd = require 'httpd'
16
17function escape_html(s)
18  return s:gsub('&', '&amp;'):gsub('<', '&lt;'):gsub('>', '&gt;'):gsub('"', '&quot;')
19end
20
21function printenv(env, headers, query)
22
23	-- we get the "environment" in the env table, the values are more
24	-- or less the same as the variable for a CGI program
25
26	-- output headers using httpd.write()
27	-- httpd.write() will not append newlines
28	httpd.write("HTTP/1.1 200 Ok\r\n")
29	httpd.write("Content-Type: text/html\r\n\r\n")
30
31	-- output html using httpd.print()
32	-- you can also use print() and io.write() but they will not work with SSL
33	httpd.print([[
34		<html>
35			<head>
36				<title>Bozotic Lua Environment</title>
37			</head>
38			<body>
39				<h1>Bozotic Lua Environment</h1>
40	]])
41
42	httpd.print('module version: ' .. httpd._VERSION .. '<br>')
43
44	httpd.print('<h2>Server Environment</h2>')
45	-- print the list of "environment" variables
46	for k, v in pairs(env) do
47		httpd.print(escape_html(k) .. '=' .. escape_html(v) .. '<br/>')
48	end
49
50	httpd.print('<h2>Request Headers</h2>')
51	for k, v in pairs(headers) do
52		httpd.print(escape_html(k) .. '=' .. escape_html(v) .. '<br/>')
53	end
54
55	if query ~= nil then
56		httpd.print('<h2>Query Variables</h2>')
57		for k, v in pairs(query) do
58			httpd.print(escape_html(k) .. '=' .. escape_html(v) .. '<br/>')
59		end
60	end
61
62	httpd.print('<h2>Form Test</h2>')
63
64	httpd.print([[
65	<form method="POST" action="form?sender=me">
66	<input type="text" name="a_value">
67	<input type="submit">
68	</form>
69	]])
70	-- output a footer
71	httpd.print([[
72		</body>
73	</html>
74	]])
75end
76
77function form(env, header, query)
78
79	httpd.write("HTTP/1.1 200 Ok\r\n")
80	httpd.write("Content-Type: text/html\r\n\r\n")
81
82	if query ~= nil then
83		httpd.print('<h2>Form Variables</h2>')
84
85		if env.CONTENT_TYPE ~= nil then
86			httpd.print('Content-type: ' .. env.CONTENT_TYPE .. '<br>')
87		end
88
89		for k, v in pairs(query) do
90			httpd.print(escape_html(k) .. '=' .. escape_html(v) .. '<br/>')
91		end
92	else
93		httpd.print('No values')
94	end
95end
96
97-- register this handler for http://<hostname>/<prefix>/printenv
98httpd.register_handler('printenv', printenv)
99httpd.register_handler('form', form)
100