const fs = require('fs');

const path = require('path');

const async = require('async');

const R = require('ramda');

const S = require('sanctuary');

const sync = (f) => (values, cb) => cb(null, f(values))

const join = (x, cb) => cb(null, path.join(process.argv[2], x));

const map = R.flip(async.map);

const output = (err, results) => {

if (err != undefined) {

process.stderr.write(String(err) + '\n');

process.exit(1);

} else {

process.stdout.write(results);

process.exit(0);

}

}

const main = () => {

async.seq(

join,

fs.readFile,

sync(String),

sync(S.lines),

map(join),

map(fs.readFile),

(files, cb) => cb(null, files.join(''))

)('index.txt', output)

}

if (process.mainModule.filename === __filename) main();