esp8266 nodeMCU script for scanning available Wifi APs

scan-ap.lua

return function (connection, req, args)
  dofile('httpserver-header.lc')(connection, 200, 'html')
  
  function ca(payload) connection:send(payload) end
  ca("<script>setTimeout(function(){window.location=window.location}, 4000)</script>")
  
  aplist = aplist or {}
  
  ca("<table>")
  ca("<tr>")
  ca("<th>ssid</th>")
  ca("<th>authmode</th>")
  ca("<th>rssi</th>")
  ca("<th>channel</th>")
  ca("</tr>")
  
  for k,v in pairs(aplist) do
    ca("<tr>")
    ca("<td>"..k.."</td>")
    ca("<td>"..v.authmode.."</td>")
    ca("<td>"..v.rssi.."</td>")
    ca("<td>"..v.channel.."</td>")
    ca("</tr>")
  end
  
  ca("</table>")
  
  function listap(t) -- (SSID : Authmode, RSSI, BSSID, Channel)
    for ssid,v in pairs(t) do
        local authmode, rssi, bssid, channel = string.match(v, "([^,]+),([^,]+),([^,]+),([^,]+)")
        aplist[ssid] = aplist[ssid] or {}
      	aplist[ssid].rssi = rssi
      	aplist[ssid].authmode = authmode
      	aplist[ssid].channel = channel
    end
  end
  
  wifi.sta.getap(listap)

end