index.js

#!/usr/bin/env node

var opn = require('opn')
var isos = require('isos')
var http = require('http')
var child = require('child_process')
var ansi = require('ansi-html-stream')
var replaceStream = require('replacestream')
var os = require('os')
var rc = require('rc')

var config = rc('bcat', {
	port: 0,
	contentType: 'text/html',
	scrollDownInterval: 1000,
	backgroundColor: '#333',
	foregroundColor: '#fefefe',
	tabLength: 4,
	tabReplace: '&nbsp;&nbsp;&nbsp;&nbsp;',
	disableTabReplace: false,
	newlineReplace: '<br />',
	disableNewlineReplace: false,
	ansi: true,
	ansiOptions: {
		foregrounds: {
			'30': { style: 'color:#fffaaa' } // black
		},
		backgrounds: {
			'40': { style: 'background-color:#fffaaa' } // black
		}
	},
	serverTimeout: 0,
	command: undefined
})

if (config.usage || config.help) {
	console.log(require('./usage.js'))
	process.exit(0)
}

cat(config.port)

/* this part is rendered into client side script (inside the browser) */
var clientConfig = {
	scrollDownInterval: config.scrollDownInterval
};

function run() {
	var ref

	function startAutoScroll() {
		ref = window.setInterval(function() {
			document.getElementById('container').scrollIntoView(false)
		}, clientConfig.scrollDownInterval)
	}

	function stopAutoScroll() {
		clearInterval(ref)
	}

	var scrollToggle = document.getElementById('autoscrollToggle')

	if (scrollToggle) {
		scrollToggle.addEventListener('change', function() {
			if (scrollToggle.checked) {
				startAutoScroll()
			} else {
				stopAutoScroll()
			}
		});
	}

	startAutoScroll()
}
/**/

var script = 'var clientConfig = ' + JSON.stringify(clientConfig) + '\n' + run.toString() + '\nrun()'

function cat(port) {

	var server = http.createServer(handler)

	server.on('listening', function () {
		var url = 'http://localhost:' + server.address().port

		if (!process.env.BROWSER) {
			console.error('The environment variable $BROWSER is not set. Falling back to default opening mechanism.')
			opn('http://localhost:' + server.address().port, { wait: false })
		} else {
			console.error('The environment variable $BROWSER is set to "' + $BROWSER + '"')
			child.spawn(process.env.BROWSER, [url], { detached: true })
		}
	})

	server.listen(port)

	server.timeout = config.serverTimeout;
}

function handler(request, response) {

	var contentType = config.contentType

	var bg = config.backgroundColor
	var fg = config.foregroundColor

	var stream = process.stdin

	if (config.ansi) {
		contentType = 'text/html'
		stream = stream.pipe(ansi(config.ansiOptions))
	}

	if (!config.disableTabReplace) {
		var tab = ''
		for (var i = 0; i < config.tabLength; i++)
			tab += ' '

		var tabStream = replaceStream(tab, config.tabReplace)
		stream = stream.pipe(tabStream)
	}

	if (!config.disableNewlineReplace) {
		var osNewLineStream = replaceStream(os.EOL, config.newlineReplace)
		var newLineStream = replaceStream('\n', config.newlineReplace)

		stream = stream.pipe(osNewLineStream).pipe(newLineStream)
	}

	response.setHeader('Content-Type', contentType)

	if (contentType === 'text/html') {

		var style = 'body { background-color: ' + bg + '; color: ' + fg + '; font-family:Monaco, Menlo, monospace; padding:2em;} ' +
			'div#headline { position: fixed; top: 2em; right: 2em ; text-align: right;} ' +
			'div#autoscroll { position: fixed; bottom: 2em; right: 2em ; }'


		response.write('<!DOCTYPE html><html><head><style>' + style + '</style></head>' +
			'<body>' +
			'<div id="headline">Pipe from terminal to browser<br> <br><code style="color:gray">started at:' + new Date() + '</code></div>' +
			'<div id="autoscroll">Auto scroll <input type="checkbox" id="autoscrollToggle" checked /></div>' +
			'<script>' + script + '</script><div id="container">')
	}

	stream.pipe(response)

	response.on('finish', function() {
		process.exit(0)
	})
}