Unmarshall DynamoDb output, command line node script, aws cli, scan, get-item

unmarshall.js

#!/usr/bin/env node
// npm init
// npm install aws-sdk
// or npm install -g aws-sdk

// Usage:
//   ./unmarshall.js '[{"H": {"S": "Hi"}}]'
//  or
//   ./unmarshall.jl "$(aws dynamodb scan --table-name "$table_name" --output json | jq -r '.Items')"

const AWS = require("aws-sdk");
var arguments = process.argv ;
// console.log(arguments) ; // 0th is node, 1st is the scriptname
var json_in = JSON.parse(arguments[2])
if (Array.isArray(json_in)){
  json_in.forEach((v) => console.log(AWS.DynamoDB.Converter.unmarshall(v)))
} else {
  console.log(AWS.DynamoDB.Converter.unmarshall(json_in))
}

Why-unmarshall.md

JSON is wordy enough already most of the time. When you want to just see it, you don't need to know about the encoding types that Dynamo needs to know about.

Here is a project that does it in a simple web page:

https://dangerfarms.github.io/unmarshall-dynamodb-json/

Here's the line of interest: https://github.com/dangerfarms/unmarshall-dynamodb-json/blob/master/index.html#L10