concat-stream

$ npm install concat-stream

then

var concat = require('concat-stream')
var fs = require('fs')
    
var read = fs.createReadStream('readme.md')
var write = concat(function(data) {})
    
read.pipe(write)

works with arrays too!

var write = concat(function(data) {})
write.write([1,2,3])
write.write([4,5,6])
write.end()
// data will be [1,2,3,4,5,6] in the above callback

works with buffers too! can't believe the deals!

var write = concat(function(data) {})
write.write(new Buffer('hello '))
write.write(new Buffer('world'))
write.end()
// data will be a buffer that toString()s to 'hello world' in the above callback

MIT LICENSE