json - NodeJS 写入日志文件(Json)

Question

我想把日志写成Json文件

newEntry =  "User: "  + lastUsername + " Time: "+now+ " Door: "+IOSDoor;
lastUserOpenClose += newEntry;

jsonString = JSON.stringify(lastUserOpenClose);

fs.writeFile("lastUserOpenClose.json", lastUserOpenClose, function(err) {
    if(err) {
        console.log(err);
    } else {
        console.log("Server-Log: The file was saved!");
    }
});

但我正在覆盖日志。 如何将内容写入 json 文件并且不覆盖旧日志？

Answer 1

你应该使用 fs.appendFile

例子:

fs.appendFile('message.txt', 'data to append', function (err) {
  if (err) throw err;
  console.log('The "data to append" was appended to file!');
});