simple-line-reader v1.0.0

simple-line-reader

Simple, buffered, line-by-line file reader with customizable buffer size.

Install

npm install simple-line-reader

yarn add simple-line-reader

Usage

const LineReader = require("simple-line-reader");

const reader = new LineReader({
  filePath: "./somefile.txt",
  bufferSize: 1024,
  skipBlank: true,
});

while (!reader.isDone) {
  console.log(reader.nextSingle());
}

API

The module exports the following functions:

• constructor
• next
• nextSingle
• close

constructor

• new LineReader(options: LineReaderOptions): LineReader

interface LineReaderOptions {
  filePath: string;
  bufferSize?: number; // Defaults to 1024 (1 kB)
  skipBlank?: boolean; // Defaults to false
}

next

• next(): string[]

It returns a next lines of current file stream.

Syntax:

const LineReader = require("simple-line-reader");

const reader = new LineReader({
  filePath: "./file.txt",
  bufferSize: 10,
});

while (!reader.isDone) {
  console.log(reader.next());
}

./file.txt

aaaa
bbbb
cccc
dddd
eeee
ffff
gggg
hhhh
iiii
jjjj
kkkk
llll
mmmm
nnnn
oooo

Output:

[ 'aaaa', 'bbbb' ]
[ 'cccc', 'dddd' ]
[ 'eeee', 'ffff' ]
[ 'gggg', 'hhhh' ]
[ 'iiii', 'jjjj' ]
[ 'kkkk', 'llll' ]
[ 'mmmm', 'nnnn' ]
[ 'oooo' ]

nextSingle

• nextSingle(): string

It returns a next single line of current file stream.

Syntax:

const LineReader = require("simple-line-reader");

const reader = new LineReader({
  filePath: "./file.txt",
  bufferSize: 10,
  skipBlank: true,
});

while (!reader.isDone) {
  console.log(reader.nextSingle());
}

./file.txt

aaaa
bbbb
cccc
dddd

eeee
ffff
gggg
hhhh

iiii
jjjj
kkkk
llll
mmmm


nnnn
oooo

Output:

aaaa
bbbb
cccc
dddd
eeee
ffff
gggg
hhhh
iiii
jjjj
kkkk
llll
mmmm
nnnn
oooo

close

• close(): void

Close the current file descriptor thereby clearing the file stream that is associated with it.

You need to call this method only if you are done before reading the whole content stream. next() and nextSingle() will call this function automatically when reaching the end of the stream.

Syntax:

const LineReader = require("simple-line-reader");

const reader = new LineReader({
  filePath: "./file.txt",
  bufferSize: 10,
  skipBlank: true,
});

console.log(reader.next());
console.log(reader.nextSingle());
console.log(reader.nextSingle());
console.log(reader.next());
console.log(reader.nextSingle());

reader.close();

./file.txt

aaaa
bbbb
cccc
dddd
eeee
ffff
gggg
hhhh
iiii
jjjj
kkkk
llll
mmmm
nnnn
oooo

Output:

[ 'aaaa', 'bbbb' ]
cccc
dddd
[ 'eeee', 'ffff' ]
gggg
[ 'hhhh' ]