Logs added to the file is not displayed on Windows

[teid]

Hi :)
First I wanted to thank you for this project. I've used it on Linux and it's a great tool !

Recently, I tried to use it on Windows Server 2016 with a Java application and log4j.

When the application adds some lines in the log file, I don't see the update in frontail.
Even if I reload the browser.

But, when I open the log file on the server with another program like Notepad++, the logs are instantly loaded in frontail.

This looks like the behavior described here:
https://docs.microsoft.com/en-us/archive/blogs/asiasupp/file-date-modified-property-are-not-updating-while-modifying-a-file-without-closing-it

They suggest to open and close a handle on the log file.
Would you accept to do this in frontail ?

Regards,
Timothée

[teid]

I modified frontail to use node-tail instead of fs-tail-stream

I changed the file lib/tail.js (it's a rough implementation, I did not take the time to report every features like stdin, initial number of lines and native tail):

/* eslint no-underscore-dangle: off */

'use strict';

const events = require('events');
const childProcess = require('child_process');
const TailLib = require('tail').Tail;
const util = require('util');
const CBuffer = require('CBuffer');
const byline = require('byline');
const commandExistsSync = require('command-exists').sync;

function Tail(path, opts) {
  events.EventEmitter.call(this);

  const options = opts || {
    buffer: 0
  };
  this._buffer = new CBuffer(options.buffer);

  let tail = new TailLib(path.join(), {
	encoding: 'utf-8',
	follow: true,
	useWatchFile: true,
	flushAtEOF: true
  });

  tail.on("line", (line) => {
    const str = line.toString();
    this._buffer.push(str);
    this.emit('line', str);
  });
}
util.inherits(Tail, events.EventEmitter);

Tail.prototype.getBuffer = function getBuffer() {
  return this._buffer.toArray();
};

module.exports = (path, options) => new Tail(path, options);

It's the option useWatchFile: true of the lib node-tail that made it work on Windows

[mthenw]

Hey,

Can you create a PR for that?

[teid]

Sure I can do that.

When useWatchFile is set to true, fs.watchFile will be used instead of fs.watch

fs.watchFile is less efficient that fs.watch, maybe we can enable it only on Windows ? Or do you want it to be an option ?

[mthenw]

I think it makes sense to enable that only on windows