kantord / emuto

manipulate JSON files

Website • Tutorial • Live demo • CLI version • Compile-to-JS version

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Emuto is a small language for manipulating and restructuring JSON and other data files. Emuto is inspired by jq and GraphQL

Features

• Transform and query data structures
• Integrate with unix commands in the command line
• Conversions between different file formats
• Supported input formats: JSON, text, csv, tsv, dsv
• Supported output formats: JSON, text
• Available as a Webpack loader

Getting started

Emuto as a CLI tool

npm install -g emuto emuto-cli

Read more in the tutorial

For Arch Linux users, also available as an AUR package

Webpack loader for emuto

yarn add --dev emuto emuto-loader

Read more in the Webpack guide

What is emuto good for? Examples

Number of items in JSON file

curl my_file.json | emuto 'length'

Your karma on HackerNews

curl https://hacker-news.firebaseio.com/v0/user/kantord.json -s | emuto '$.karma'

Convert another command's output to JSON

ls | emuto -i=raw '$[0:-1]'

See number of NPM dependencies

cat package.json | emuto -c '$.dependencies | keys | length'

List available scripts in package.json

cat package.json | emuto -c '$.scripts | keys | join " · "'

Get only the relevant data from a huge JSON file

curl https://api.github.com/repos/stedolan/jq/commits |\
emuto -c 'map ($ => $ { commit { message } committer { login } } )'

Automate the restructuring of data by creating scripts with emuto

restructure.emu

#! emuto -s

$
  | map ($ => $ { commit { message } committer { login } } )
  | map ($ => {
      "committer": $.committer.login,
      "message":   $.commit.message,
    })

Calling your script

curl https://api.github.com/repos/stedolan/jq/commits | ./restructure.emu

Contributing Guide

Read our contributing guide to learn about our development process, how to create bugfixes and improvements, and how to build and test your changes to emuto.