gistfile1.txt

var crypto = require('crypto');

// change to 'md5' if you want an MD5 hash
var hash = crypto.createHash('sha1');

// change to 'binary' if you want a binary hash.
hash.setEncoding('hex');

// the text that you want to hash
hash.write('hello world');

// very important! You cannot read from the stream until you haven't called end()
hash.end();

// and now you get the resulting hash
var sha1sum = hash.read();
cosnole.log(sha1sum);