How to use byline - 10 common examples

const through2 = require("through2");
const byline = require("byline");
const turf = require("@turf/turf");
const OSRM = require("osrm");
const random = require("random");
const moment = require("moment");

const osrm = new OSRM("./data/nyc.osrm");

const DRIFT = 0.01;
const PERIOD = 20;
var normal = random.normal();

var k = 0;

process.stdin.pipe(byline.createStream()).pipe(
  through2((chunk, enc, next) => {
    k++;
    if (k % 1000 === 0) console.error(k);
    var line = chunk.toString();

    if (line.length && k > 1) {
      // skip header or trailing endline
      var cell = line.split(",");

      var record = {
        timeA: moment(cell[1]),
        timeB: moment(cell[2]),
        ptA: [+cell[5], +cell[6]],
        ptB: [+cell[9], +cell[10]]
      };

processCallback: (process) => {
        byline(process.stderr).on('data', (chunk) => {
          // if (chunk.startsWith('Counting objects: ')) {
          //   const percent = this.tryParse(chunk)
          //   if (percent) {
          //     console.log('total object', percent)
          //     this.setReceivingProgress(repo, percent)
          //   }
          //   return
          // }
          if (chunk.startsWith('Receiving objects: ')) {
            const percent = this.tryParse(chunk);
            if (percent) {
              // console.log('receiving progress', percent)
              this.setReceivingProgress(repo, percent);
            }
            return;
          }

exports.handler = function(event, context) {
    console.log('Received event: ', JSON.stringify(event, null, 2));
    
    /* == Streams ==
    * To avoid loading an entire (typically large) log file into memory,
    * this is implemented as a pipeline of filters, streaming log data
    * from S3 to ES.
    * Flow: S3 file stream -> Log Line stream -> Log Record stream -> ES
    */
    var lineStream = new LineStream();
    // A stream of log records, from parsing each log line
    var recordStream = new stream.Transform({objectMode: true})
    recordStream._transform = function(line, encoding, done) {
        var logRecord = parse(line.toString());
        var serializedRecord = JSON.stringify(logRecord);
        this.push(serializedRecord);
        totLogLines ++;
        done();
    }

    event.Records.forEach(function(record) {
        var bucket = record.s3.bucket.name;
        var objKey = decodeURIComponent(record.s3.object.key.replace(/\+/g, ' '));
        s3LogsToES(bucket, objKey, context, lineStream, recordStream);
    });
}

async function run() {
    let stream = fs.createReadStream('txt/millionsOfGuesses.txt');
    stream.setEncoding('utf8');

    // read the file stream a line at a time.
    let lineStream = byline.createStream(stream, { keepEmptyLines: false });

    // awaitable interface for reading the stream.
    let reader = aw.createReader(lineStream);

    // readline for prompting the user.
    const rl = readline.createInterface({
        input: process.stdin,
        output: process.stdout
    });

    try {
        let line;
        while (null !== (line = await reader.readAsync())) {
            let guessedCard = await checkGuess(rl, line);

            if (guessedCard) {

export function spawn (cmd, args, opts) {
  const child = chip.spawn(cmd, args, opts);
  const stdout = byline(child.stdout);
  const stderr = byline(child.stderr);
  const lines = [];

  let onData = function (data) {
    const time = (new Date()).getTime();
    lines.push([ time, data.toString() ]); // TODO chalk stdout/stderr?
    const { thresholds } = this; // eslint-disable-line no-invalid-this
    if (thresholds) {
      for (const key in thresholds) {
        if (data.indexOf(key) >= 0) {
          const p = thresholds[key];
          log.showProgress(p);
          if (DEBUG_THRESHOLDS) {
            lines.push([ time, '************' ]);
            lines.push([ time, p + ': ' + key ]);
            lines.push([ time, '************' ]);

export function spawn (cmd, args, opts) {
  const child = chip.spawn(cmd, args, opts);
  const stdout = byline(child.stdout);
  const stderr = byline(child.stderr);
  const lines = [];

  let onData = function (data) {
    const time = (new Date()).getTime();
    lines.push([ time, data.toString() ]); // TODO chalk stdout/stderr?
    const { thresholds } = this; // eslint-disable-line no-invalid-this
    if (thresholds) {
      for (const key in thresholds) {
        if (data.indexOf(key) >= 0) {
          const p = thresholds[key];
          log.showProgress(p);
          if (DEBUG_THRESHOLDS) {
            lines.push([ time, '************' ]);
            lines.push([ time, p + ': ' + key ]);
            lines.push([ time, '************' ]);
          }

const getSurroundingCode = (file, lineNumber, cb) => {
  const start = lineNumber - SURROUNDING_LINES
  const end = lineNumber + SURROUNDING_LINES

  const reader = createReadStream(file, { encoding: 'utf8' })
  const splitter = new byline.LineStream({ keepEmptyLines: true })
  const slicer = new CodeRange({ start, end })

  // if the slicer has enough lines already, no need to keep reading from the file
  slicer.on('done', () => reader.destroy())

  pump(reader, splitter, slicer, (err) => {
    // reader.destroy() causes a "premature close" error which we can tolerate
    if (err && err.message !== 'premature close') return cb(err)
    cb(null, slicer.getCode())
  })
}

exports.parserExecute = function (urls) {
  if (urls && Array.isArray(urls)) {
    var results = [];
    for (var i = 0, l = urls.length; i < l; i++) {
      results.push(parseUrl(urls[i]));
    }
    return results;
  } else {
    var stdin = process.stdin;
    var stdout = process.stdout;
    var stream = byline.createStream(stdin);

    stream.on('end', function () {
      process.exit(0);
    });

    stream.on('close', function () {
      process.exit(0);
    });

    stream.on('data', function (line) {
      stdout.write(JSON.stringify(parseUrl(line.toString())) + '\n');
    });
  }
};

.on('root',function(){
        var rs = fs.createReadStream(npmfile); 
        rs.setEncoding('ascii')
        
        var linestream = byline.createStream()

        linestream.on('data', function(line){

	  try {
            try {
	      var data = JSON.parse( cutcomma(line) )
            }
            catch(e){
              console.log(e)
              return
            }

	    var v = data.value

	    var doc = {
	      name:v.name,

exports.parserExecute = function (urls) {

  if (urls && Array.isArray(urls)) {
    var results = [];
    for (var i = 0, l = urls.length; i < l; i++) {
      results.push(parseUrl(urls[i]));
    }
    return results;
  } else {
    var stdin = process.stdin;
    var stdout = process.stdout;
    var stream = byline.createStream(stdin);

    stream.on('end', function () {
      process.exit(0);
    });

    stream.on('close  ', function () {
      process.exit(0);
    });

    stream.on('data', function (line) {
      stdout.write(JSON.stringify(parseUrl(line.toString())) + '\n');
    });
  }
};