fs.appendFileSync('file_name').toString().split('n').forEach(function(line){
    app.console.log("called append");
    var sEntry = line.split("=");
    if (sEntry.length == 2) {
      if (sEntry[0] == "LINE_IAM_INTERESTED") {
      app.console.log("found one!!!!");
      }
    }
  });