lib/middlewares/respond.js
function _watchRuleFile(file, callback){
  fs.watchFile(file, function(curr, prev){
    log.warn('The rule file has been modified!');
    callback();
  });
}
function _watchRuleFile(file, callback){
  fs.watchFile(file, function(curr, prev){
    log.warn('The rule file has been modified!');
    callback();
  });
}
function _watchRuleFile ( file , callback ) { fs . watchFile ( file , function ( curr , prev ) { log . warn ( 'The rule file has been modified!' ) ; callback ( ) ; } ) ; }
Watch the rule file to support applying changed rules without restart the proxy

@param {String} file the path of the file
@param {Function} callback
Watch the rule file to support applying changed rules without restart the proxy