require "luasocket" -- warning: depending on the version of luasocket that we use, -- we have to change `settimeout' to `timeout' (as done here) function receive (connection) connection:timeout(0) -- do not block local s, status = connection:receive(2^10) if status == "timeout" then coroutine.yield(connection) end return s, status end function download (host, file) local c = assert(socket.connect(host, 80)) local count = 0 -- counts number of bytes read c:send("GET " .. file .. " HTTP/1.0\r\n\r\n") while true do local s, status = receive(c) count = count + string.len(s) if status == "closed" then break end end c:close() print(file, count) end threads = {} -- list of all live threads function get (host, file) -- create coroutine local co = coroutine.create(function () download(host, file) end) -- insert it in the list table.insert(threads, co) end function dispatcher () while true do local n = table.getn(threads) if n == 0 then break end -- no more threads to run local connections = {} for i=1,n do local status, res = coroutine.resume(threads[i]) if not res then -- thread finished its task? table.remove(threads, i) break else -- timeout table.insert(connections, res) end end if table.getn(connections) == n then socket.select(connections) end end end host = "www.w3.org" get(host, "/TR/html401/html40.txt") get(host,"/TR/2002/REC-xhtml1-20020801/xhtml1.pdf") get(host,"/TR/REC-html32.html") get(host, "/TR/2000/REC-DOM-Level-2-Core-20001113/DOM2-Core.txt") dispatcher() -- main loop