Get field from json

json.js

// Small tool to obtain a field from a JSON file

// Read the JSON from STDIN

var buff = "";

if (process.argv.length <= 1) {
	console.error("Must inform the field to be extracted");
	process.exit(-1);
}


const field = process.argv[2];

process
	.stdin
    .on('data', data => { buff
      buff += data;
    })
    .on('end', () => {
      	const json = JSON.parse(buff);
		if (json[field] === undefined) {
			console.error("ERROR: field is undefined");
			process.exit(-1);
		}
		console.log(json[field]);
    });

Very simple utility, lacking a lot of error handling and such, just to parse a JSON from STDIN and output a certain field