NODE.JS - How to generate file's Checksum (CRYPTO)

nodejs.checksum.js

var fs = require('fs');
var crypto = require('crypto');

fs.readFile('file.pdf', function(err, data) {
  var checksum = generateChecksum(data);
  console.log(checksum);
});

function generateChecksum(str, algorithm, encoding) {
    return crypto
        .createHash(algorithm || 'md5')
        .update(str, 'utf8')
        .digest(encoding || 'hex');
}

Neat. Thank you!

Thank y♂u Sir!

how to use the output since it is printed in console?

You could change the console.log to a return statement and have the whole fs.readFile function saved to a variable as a function expression. Then you would have your hash string in a variable to use as you wish.