Convert JSON to bash environment variables

Question

I wrote this beauty a while back to run on a server and convert environment variables from JSON to a bash .env format.

#!/usr/bin/env node
var strings = []
process.stdin.resume()
process.stdin.setEncoding('utf8')
process.stdin.on('data', function(data) {
  var json = JSON.parse(data)
  for (var key in json) {
    var val = json[key]
    strings.push(key + '="' + val + '"')
  }
})
process.stdin.on('end', function() {
  var output = strings.join('\n')
  process.stdout.write(output)
})

Can this be done without node, just bash? I'm having trouble getting this working on a server without node installed or without the correct path specified.

Answer 1

Yes, assuming that all the key/val pairs you want to keep are in the form:

"key":"stringval"
"key":numval
"key":true or false or null

(with optional space around the colon):

#!/bin/sh
tr -d '\n' |
  grep -o '"[A-Za-z_][A-Za-z_0-9]\+"\s*:\s*\("[^"]\+"\|[0-9\.]\+\|true\|false\|null\)' |
  sed 's/"\(.*\)"\s*:\s*"\?\([^"]\+\)"\?/\1="\2"/'

Example:

cat manifest.json | ./json2env.sh

yields

name="Polymer Starter Kit"
short_name="Polymer Starter Kit"
src="images/touch/icon-72x72.png"
sizes="72x72"
type="image/png"
test1="0.123"
test2="true"
test3="false"
test4="null"