streaming parser for fake-ssh logins file

fakessh-parser.js

/*
 * Takes a tab separated file from tylermenezes' fake-ssh:
 *
 * 1380751629	username	tylermenezes
 * 1380751629	password	foo
 * 1380751634	a_password	None
 * 1380751634	username	tylermenezes
 * 1380751634	password	foobar
 * 1380751638	a_password	None
 * ...
 *
 * Usage:
 *
 *     node index.js > passwords.csv
 * 
 */

var fs = require('fs');

var rst = fs.createReadStream("logins");

rst.setEncoding('utf8');

var START_LINE_POS = 11; //ignore timestamp

var passwords = {};

var line = [];
rst.on('data', function(chunk) {
	var linePos = 0;
	for (var i = 0, l = chunk.length; i < l; i++) {
		var c = chunk[i];
		if (c == '\n') {
			parseLine(line);
			linePos = 0;
			line = [];
		} else {
			if (linePos >= START_LINE_POS) {
				line.push(c);
			}
			linePos++;
		}
	}
});

rst.on('end', function() {
	printCsv(passwords);
	rst.close();
});

function parseLine(arr) {
	if (arr[0] == 'p') {
		//password
		var password = arr.slice(9).join('');
		passwords[password] |= 0;
		passwords[password]++;
	}
}

function printCsv(obj) {
	for (var key in obj) {
		//csv format for dealing with commas
		var escaped = ['"', key.replace(/"/g, '""'), '"'].join('');
		console.log([escaped, obj[key]].join(','))
	}
}