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Read large text files line by line (synchronous) for Node.js

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Build Status #node-readlines Reading file line by line may seem like a trivial problem, but in node, there is no straightforward way to do it. There are a lot of libraries using Transform Streams to achieve it, but it seems like a overkill, so I've wrote simple version using only the filesystem module of node. Note that this is synchronous library.

Install with npm install n-readlines


##Documentation ###new readlines(filename, [options]); ###new readlines(fd, [options]);

Arguments

  • filename - String path to the file you want to read from
  • fd - File descriptor
  • options - Object
    • readChunk - Integer number of bytes to read at once. Default: 1024
    • newLineCharacter - String new line character, only works with one byte characters for now. Default: \n which is 0x0a hex encoded

node-readlines can handle files without newLineCharacter after the last line


###readlines.next() Returns buffer with the line data without the newLineCharacter or false if end of file is reached.


###readlines.reset() Resets the pointer and starts from the beginning of the file. This works only if the end is not reached.


##Example

var lineByLine = require('n-readlines');
var liner = new lineByLine('./textFile.txt');

var line;
var lineNumber = 0;
while (line = liner.next()) {
    console.log('Line ' + lineNumber + ': ' + line.toString('ascii'));
    lineNumber++;
}

console.log('end of line reached');

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Read large text files line by line (synchronous) for Node.js

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