elua/romfs/lhttpd.lua

-- Check platform
if pd.board() ~= 'EK-LM3S8962' and pd.board() ~= 'EK-LM3S6965' and pd.board() ~= 'EAGLE-100' and pd.board() ~= 'EK-LM3S9B92' then
  print( pd.board() .. " not supported by this example" )
  return
end

-- Mapping between file extension (and request) and HTTP response
local extmap = {
  txt = "text/plain",
  htm = "text/html",
  pht = "text/html",
  gif = "image/gif",
  jpg = "imge/jpeg",
  png = "image/png",
  lua = "text/html"
}

local basedir = "/rom/"
reqdata = {}

-- Auxiliary function: execute the given code with a substituted "print"
-- that prints everything to a string, return the code output
local function docode(thecode)
  local strbuf = {}
  local oldprint, newprint =  print, function(...)
    local total, idx = select('#', ...)
    for idx = 1, total do
      strbuf[#strbuf + 1] = tostring(select(idx, ...)) .. (idx == total and '\n' or '\t')
    end
  end
  print = newprint
  local f = loadstring(thecode)
  if f then
    f()
  else
    print ">>> Invalid Lua code <<<"
  end
  print = oldprint
  collectgarbage('collect')
  return table.concat(strbuf)
end

function process(header)
    -- look for first line
	local s, e = header:find("[^\n]+\n")
	local reqstr = header:sub(s, e)
  local respheader, respdata = '', ''
  
  reqdata = {}
	-- check if the request is valid, also keep the actual request
	local i, valid, req = 0, false
	for w in reqstr:gmatch("%S+") do
	  valid = ( i == 0 and w == "GET" ) or valid
	  req = ( i == 1 and w ) or req
	  i = i + 1
	end

    -- valid is true if the request is valid, req has the request string
	if valid then
    -- now look for all parameters in this request (if any)
    local fname = ""
    if req:find("%?") then
      local rest
      _, _, fname, rest = req:find("(.*)%?(.*)")
      -- small trick: end "rest" with a "&" for easier processing
      -- now look for "var=value" pairs in the request (GET encoding)
      rest = rest .. "&"
      for crtpair in rest:gmatch("[^&]+") do
        local _, __, k, v = crtpair:find("(.*)=(.*)")
        -- replace all "%xx" characters with their actual value
        v = v:gsub("(%%%x%x)", function(s) return string.char(tonumber(s:sub(2, -1), 16)) end)
        reqdata[k] = v
      end
    else
      fname = req
    end
    fname = ( fname == "/" ) and "index.pht" or fname:sub(2, -1)
    s, e = fname:find("%.[%a%d]+$")
    local ftype = fname:sub(s+1, e):lower()
    ftype = (#ftype > 0 and ftype) or "txt"
    fname = basedir .. fname
    
    -- now "fname" has the name of the requested file, and "reqdata" the actual request data
    -- also "ftype" holds the file type (actually its extension)
    local tf = io.open(fname, "r")
    if tf then
      respheader = "HTTP/1.1 200 OK\r\nConnection: close\r\nServer: eLua-miniweb\r\nContent-Type: " .. extmap[ftype or "txt"] .. "\r\n\r\n"
      -- Preprocess "lua" and "pht" files: run the Lua ones, parse the .htm ones for "<?lua ... ?>" sequences
      if ftype == "pht" or ftype == "lua" then
        local fdata = tf:read("*a")
        if ftype == "lua" then
          respdata = docode(fdata)
        else
          -- Look for <?lua ... lua> patterns and execute them accordingly
          respdata = fdata:gsub("<%?lua(.-)%?>", docode)
        end
      else
        respdata = tf:read("*a")
      end
      tf:close()
    else
      respheader = "HTTP/1.1 404 Not Found\r\nConnection: close\r\nServer: eLua-miniweb\r\nContent-Type: text/html\r\n\r\nPage not found"
    end
  end
  return respheader .. respdata
end

while true do
  local sock, remoteip, err = net.accept( 80 )
  print( "Got connection on socket", sock )
  print( "Remote ip: " .. net.unpackip( remoteip, "*s" ) )
  local response, err2 = net.recv( sock, 1024 )
  print "Got request"
  local httpdata = process( response )
  if #httpdata > 0 then
    print "Sending response"
    net.send( sock, httpdata )
  end
  net.close( sock )
  reqdata = {}
  collectgarbage('collect')
end