Commit a58bb71c authored by Sergey Lyubka's avatar Sergey Lyubka

Added Lua section to the user manual

parent fc9a9593
......@@ -279,6 +279,50 @@ must be for a file name only, not including directory name. Example:
mongoose -hide_files_patterns secret.txt|even_more_secret.txt
# Lua Server Pages
Pre-built Windows and Mac mongoose binaries have built-in Lua Server Pages
support. That means it is possible to write PHP-like scripts with mongoose,
using Lua programming language instead of PHP. Lua is known
for it's speed and small size. Mongoose uses Lua version 5.2.1, the
documentation for it can be found at
[Lua 5.2 reference manual](http://www.lua.org/manual/5.2/).
To create a Lua Page, make sure a file has `.lp` extension. For example,
let's say it is going to be `my_page.lp`. The contents of the file, just like
with PHP, is HTML with embedded Lua code. Lua code must be enclosed in
`<? ?>` blocks, and can appear anywhere on the page. For example, to
print current weekday name, one can write:
<p>
<span>Today is:</span>
<? print(os.date("%A")) ?>
</p>
Note that this example uses function `print()`, which prints data to the
web page. Using function `print()` is the way to generate web content from
inside Lua code. In addition to `print()`, all standard library functions
are accessible from the Lua code (please check reference manual for details),
and also information about the request is available in `request_info` object,
like request method, all headers, etcetera. Please refer to
`struct mg_request_info` definition in
[mongoose.h](https://github.com/valenok/mongoose/blob/master/mongoose.h)
to see what kind of information is present in `request_info` object. Also,
[page.lp](https://github.com/valenok/mongoose/blob/master/test/page.lp)
contains some example code that uses `request_info`.
One substantial difference of mongoose's Lua Pages and PHP is that Mongoose
expects Lua page to output HTTP headers. Therefore, **at the very beginning of
every Lua Page must be a Lua block that outputs HTTP headers**, like this:
<? print('HTTP/1.0 200 OK\r\nContent-Type: text/html\r\n\r\n') ?>
<html><body>
... the rest of the web page ...
It is easy to do things like redirects, for example:
<? print('HTTP/1.0 302 Found\r\nLocation: http://google.com\r\n\r\n') ?>
# Common Problems
- PHP doesn't work - getting empty page, or 'File not found' error. The
reason for that is wrong paths to the interpreter. Remember that with PHP,
......
......@@ -2,6 +2,7 @@
-- Lua server pages have full control over the output, including HTTP
-- headers they send to the client. Send HTTP headers:
print('HTTP/1.0 200 OK\r\nContent-Type: text/html\r\n\r\n')
?><html><body>
<p>This is an example Lua server page served by
......@@ -10,6 +11,14 @@ Mongoose has Lua, Sqlite, and other functionality built in the binary.
This example page stores the request in the Sqlite database, and shows
all requests done previously.</p>
<p> Today is <? print(os.date("%A")) ?>
<p> HTTP headers: <br>
<?
for name, value in pairs(request_info.http_headers) do
print(name, ' : ', value, '<br>')
end
?>
<pre>
<?
-- Open database
......
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