linereader

linereader

Reading a url or file line by line. Forked from line-by-line, and made some improvements:

• change process.nextTick to setImmediate
• add lineno (number of line)
• support url with the http or https prefix, case-insensitive
• use iconv-lite, support more encoding
• use StringDecoder when encoding set to utf8, ascii or base64

Install

npm install linereader

Usage

var LineReader = require('linereader');
var lr = new LineReader('./linereader.js');
// var lr = new LineReader('./linereader.js', {skipEmptyLines: true});
// var lr = new LineReader('https://github.com/');
// var lr = new LineReader('https://raw.githubusercontent.com/nswbmw/N-blog/master/public/images/lufei.jpg', {encoding: "base64"});
// var lr = new LineReader('HTTP://www.hot3c.com', {encoding: 'Big5'});

lr.on('error', function (err) {
  console.log(err);
  lr.close();
});

lr.on('line', function (lineno, line) {
  if (lineno <= 100) {
    console.log(lineno + "   " + line);
  } else {
    lr.close();
  }
  lr.pause();
  setTimeout(function () {
    lr.resume();
  }, 100);
});

lr.on('end', function () {
  console.log("End");
});

API

Class: LineReader(path [, options])

• path: a file path or url.

• options: an object with the following defaults: {encoding: 'utf8', skipEmptyLines: false}.

NB: encoding refer to iconv-lite. when encoding set to utf8, ascii or base64, linereader will use StringDecoder automatically. If skipEmptyLines set to true, empty lines don't trigger a 'line' event but still keep its lineno.

Event: 'line'

lr.on('line', function (lineno, line) {
  ...
}

Emitted on every line read. lineno is the current line number, line contains the line without the line ending character.

Event: 'error'

lr.on('error', function (err) {
  ...
}

Emitted if an error occurred. err contains the error object.

Event: 'end'

lr.on('end', function () {
  ...
}

Emitted if all lines are read or after using lr.close().

lr.pause()

Call this method to stop emitting 'line' events.

lr.resume()

After calling this method, 'line' events gets emitted again.

lr.close()

Stops emitting 'line' events and emits the 'end' event.

Test

node ./example

License

MIT