tailfd directory example

tailfd-dir.js

var fs =require('fs')
var path = require('path')
// these will need to be in the package.json
var tailfd = require('tailfd')
var through = require('through2')
// use:
// var taildir = require('./')
// var stream = taildir(dir)
// stream.on('data',function(data){
//    console.log(data.line)
//    console.log(data.info.filePath,'the full path to the file')
// })

module.exports = function(dir){

  var watchers = {}
  var stream = through.obj()
  var ended = false;

  setInterval(function(){
    fs.readdir(dir,function(err,files){
      if(err) return console.log('error reading dir',err)
      var add = []
      // look at all files and find ones that we are not watching
      files.forEach(function(file){
        if(file === '.') return;
        var fullPath = path.join(dir,file)
        if(!watchers[fullPath]) add.push(fullPath)
      })

      if(!add.length) return
      
      add.forEach(function(fullPath){
        fs.stat(fullPath,function(err,stat){
          if(err) return console.log('error stat ',err)
          if(!stat.isFile()) return; // only follow files. probably want to ignore more ethan just this
          watchers[fullPath] = tailfd(fullPath,function(line,fdInfo){
            // set the file path in fdInfo
            fdInfo.filePath = fullPath
            // send data event with line and info so it can be a normal stream
            if(!ended) stream.write({line:line,info:fdInfo})
          })
        })
      })
    })
  },5000).unref()

  // support pause and resume essential for making programs the don't blow up.
  stream.on('pause',function(){
    Object.keys(watchers).forEach(function(pause){
      watchers[k].pause()
    })
  })

  stream.on('drain',function(){
    Object.keys(watchers).forEach(function(pause){
      watchers[k].resume()
    })
  })

  // cleanup when you are done with the stream
  stream.on('end',cleanup).on('error',cleanup)

  return stream

  function cleanup(){
    ended = true
    Object.keys(watchers).forEach(function(k){
      watchers[k].close()
    })
  }
}