[SOLVED] Is there anyway to have a filesystem-like facility on ESP8266?

Thank you all for everything, the problem has been solved. Here are the results:

configFile = null;
configInit = function(){
  if (configFile === null) {
    configFile = getFile();
  }
};
configWrite = function(index, value){
  configInit();
  configFile.write(index, value);
};
configRead = function(index){
  configInit();
  return E.toString(configFile.read(index));
};

Usage:

>configWrite(0, "hello")
=undefined
>configWrite(1, "world")
=undefined
>configRead(0)
="hello"
>configRead(1)
="world"
>