var fs = require('fs')
var createSeriesStream = require('series-stream')
 
var ss = createSeriesStream()
 
var file1 = '/path/to/file1'
var file2 = '/path/to/file2'
var file3 = '/path/to/file3'
var outfile = '/path/to/outfile'
 
// Add streams in the order you want them to pipe out
ss.add(fs.createReadStream(file3))
ss.add(fs.createReadStream(file1))
ss.add(fs.createReadStream(file2))
 
ss.pipe(fs.createWriteStream(outfile))
// Outfile now contains the contents of file 3, 1 and 2 in that order