Cookbooks
Lua
Chapter 11. HTML and the Web
Downloading a web page

Lua:
Downloading a web page

How to:

Lua isn’t equipped out of the box for web tasks, but with the socket library and http module, it’s a cinch. Here’s a quick example using LuaSocket:

-- Don't forget to install LuaSocket: `luarocks install luasocket`
local http = require("socket.http")
local body, code = http.request("http://www.example.com")

if code == 200 then
    print(body)  -- Success! Prints the web page content.
else
    print("Something went wrong :(", code)
end

Sample Output:

<!doctype html>
<html>
<head>
    <title>Example Domain</title>
...

Deep Dive

Before LuaSocket, downloading web content in Lua was more cumbersome. Alternates like using io.popen to call curl or wget were common.

LuaSocket has been around since 2004, making network interactions like HTTP requests straightforward in Lua. It works by wrapping TCP/IP socket API calls into easy-to-use Lua functions. For HTTPS, LuaSec can be layered on.

Lua’s extensibility means you can also use other Lua-based frameworks or modules, like OpenResty for more complex web interactions within a high-performance web server environment.

Keep in mind, if you’re doing hefty web scraping or complex processing, Lua may not be your go-to; Python with libraries like Requests and Beautiful Soup might serve you better.

See Also

Parsing HTML