winston.log(‘info‘, ‘Hello distributed log files!‘);
  winston.info(‘Hello again distributed logs‘);

  winston.level = ‘debug‘;
  winston.log(‘debug‘, ‘Now my debug messages are written to console!‘);

上述代码和下述代码效果一样

var winston = require(‘winston‘);
var logger = new winston.Logger();
 
logger.log(‘info‘, ‘Hello distributed log files!‘);
logger.info(‘Hello again distributed logs‘);


By default, only the Console transport is set on the default logger. You can add or remove transports via the add() and remove() methods:

 默认情况下，仅在默认logger设置控制台传输。传输使用console和文件. 您可以通过add（）和remove（）方法添加或删除传输：

补充:有一个比較值得一提的是winston-irc，你能够用来把日志输出到你的团队的IRC渠道。

https://github.com/winstonjs/winston/blob/master/docs/transports.md  是transports的文档地址.

winston.add(winston.transports.File, { filename: ‘somefile.log‘ });    //这里是将日志信息放到somefile.log文件中

winston.remove(winston.transports.Console);  //这个只是将日志信息打印出来

2.实例化自己的logger

If you would prefer to manage the object lifetime of loggers you are free to instantiate them yourself:

如果你想管理记录器的对象生命周期，你可以自由实例化它们:

1.第一种实例化的方法

var logger = new (winston.Logger)({
    transports: [
      new (winston.transports.Console)(),               //console.log
      new (winston.transports.File)({ filename: ‘somefile.log‘ })      //写日志文件
    ]
  });

You can work with this logger in the same way that you work with the default logger:

  //
  // Logging
  //
  logger.log(‘info‘, ‘Hello distributed log files!‘);
  logger.info(‘Hello again distributed logs‘);

  //
  // Adding / Removing Transports
  //   (Yes It‘s chainable)
  //
2.第二种实例化的方法
  logger
    .add(winston.transports.File)                 //自由实例化他们的第二个方法,使用logger对象
    .remove(winston.transports.Console);

3.第三种实例化的方法
You can also wholesale reconfigure a winston.Logger instance using the configure method:

var logger = new winston.Logger({
    level: ‘info‘,
    transports: [
      new (winston.transports.Console)(),
      new (winston.transports.File)({ filename: ‘somefile.log‘ })
    ]
  });

  //
  // Replaces the previous transports with those in the
  // new configuration wholesale.
  //这是用configure重新实例化的一个
  logger.configure({
    level: ‘verbose‘,
    transports: [
      new (require(‘winston-daily-rotate-file‘))(opts)
    ]
  });

Logging with Metadata  元数据

In addition to logging string messages, winston will also optionally log additional JSON metadata objects. Adding metadata is simple:

除了记录字符串消息之外，winston还将可选地记录附加的JSON元数据对象。 添加元数据很简单：还能记录对象的形式

winston.log(‘info‘, ‘Test Log Message‘, { anything: ‘This is metadata‘ });

这些对象的存储方式因传输而异（以最好地支持所提供的存储机制）。 以下是每个传输处理元数据的快速摘要：

1. Console: Logged via util.inspect(meta)
2. File: Logged via util.inspect(meta)

Multiple transports of the same type  同一类型的多个transports

可以使用相同类型的多个传输，例如 winston.transports.File通过在构建传输时传递自定义名称。

定义了两个文件,一个是info,一个是error文件

var logger = new (winston.Logger)({
  transports: [
    new (winston.transports.File)({
      name: ‘info-file‘,
      filename: ‘filelog-info.log‘,
      level: ‘info‘
    }),
    new (winston.transports.File)({
      name: ‘error-file‘,
      filename: ‘filelog-error.log‘,
      level: ‘error‘
    })
  ]
});

If you later want to remove one of these transports you can do so by using the string name. e.g.:

logger.remove(‘info-file‘);

In this example one could also remove by passing in the instance of the Transport itself. e.g. this is equivalent to the string example above;这只是另外一种remove file的方法

var infoFile = logger.transports[0];
logger.remove(infoFile);

Profiling 分析

In addition to logging messages and metadata, winston also has a simple profiling mechanism implemented for any logger:

除了记录消息和元数据之外，winston还具有为任何记录器实现的简单分析机制：

//
  // Start profile of ‘test‘
  // Remark: Consider using Date.now() with async operations
  //
  winston.profile(‘test‘);

  setTimeout(function () {
    //
    // Stop profile of ‘test‘. Logging will now take place:
    //   "17 Jan 21:00:00 - info: test duration=1000ms"
    //
    winston.profile(‘test‘);
  }, 1000);

String interpolation 字符串插值

The log method provides the same string interpolation methods like util.format.字符串的拼接

logger.log(‘info‘, ‘test message %s‘, ‘my string‘);
// info: test message my string

logger.log(‘info‘, ‘test message %d‘, 123);
// info: test message 123

logger.log(‘info‘, ‘test message %j‘, {number: 123}, {});
// info: test message {"number":123}
// meta = {}

logger.log(‘info‘, ‘test message %s, %s‘, ‘first‘, ‘second‘, {number: 123});
// info: test message first, second
// meta = {number: 123}

logger.log(‘info‘, ‘test message‘, ‘first‘, ‘second‘, {number: 123});
// info: test message first second
// meta = {number: 123}

logger.log(‘info‘, ‘test message %s, %s‘, ‘first‘, ‘second‘, {number: 123}, function(){});
// info: test message first, second
// meta = {number: 123}
// callback = function(){}

logger.log(‘info‘, ‘test message‘, ‘first‘, ‘second‘, {number: 123}, function(){});
// info: test message first second
// meta = {number: 123}
// callback = function(){}

Querying Logs 日志查询

winston支持winston自己查询日志,这个类似于有点数据库的感觉.

Winston supports querying of logs with Loggly-like options. See Loggly Search API. Specifically: File, Couchdb,Redis, Loggly, Nssocket, and Http.

var options = {
    from: new Date - 24 * 60 * 60 * 1000,
    until: new Date,
    limit: 10,
    start: 0,
    order: ‘desc‘,
    fields: [‘message‘]
  };

  //
  // Find items logged between today and yesterday.
  //
  winston.query(options, function (err, results) {
    if (err) {
      throw err;
    }

    console.log(results);
  });

Streaming Logs 创建数据流日志

Streaming allows you to stream your logs back from your chosen transport.

//
  // Start at the end.
  //
  winston.stream({ start: -1 }).on(‘log‘, function(log) {
    console.log(log);
  });