jo creates a JSON string on stdout from words given it as arguments or read
from stdin. Without option -a it generates an object whereby each word is a
key=value (or key@value) pair with key being the JSON object element and value
its value. jo attempts to guess the type of value in order to create number
(using strtod(3)), string, or null values in JSON.

WWW: https://github.com/jpmens/jo