Streaming from stdin or a file

stdin-and-fs-stream.js

// Depends on `through`
//
//     $ npm install through
//
// Usage:
//
//     $ echo 'hello' | node stdin-and-fs-stream.js 
//     $ echo 'hello' > tmp && node stdin-and-fs-stream.js tmp
//
var fs = require('fs'),
    through = require('through');

var tr = through(function (buf) {
  console.log(buf.toString());
});


var stream;

if (process.argv.length > 2) {
  stream = fs.createReadStream(process.argv[2]);
}
else {
  stream = process.stdin;
  setImmediate(function () {
    stream.push(null);
  });
}

stream.pipe(tr).pipe(process.stdout);