json

What is json?

The 'json' npm package provides a simple command-line tool for working with JSON data. It allows users to easily manipulate JSON objects, extract specific fields, and format JSON data in a readable way.

What are json's main functionalities?

Extracting specific fields

This feature allows you to extract specific fields from a JSON file. In this example, it extracts the 'name' field from 'data.json'.

json -f data.json name

Pretty-printing JSON

This feature formats JSON data in a readable way with indentation. The '-i' flag is used to pretty-print the JSON content of 'data.json'.

json -i data.json

Updating JSON data

This feature allows you to update JSON data directly from the command line. The '-I' flag is used to modify the file in place, and the '-e' flag is used to execute the provided JavaScript expression to update the 'name' field.

json -I -f data.json -e 'this.name="newName"'

Other packages similar to json

jq

jq is a lightweight and flexible command-line JSON processor. It allows for complex filtering, transformation, and extraction of JSON data. Compared to 'json', jq offers more advanced querying capabilities and a more powerful syntax for manipulating JSON data.

jsonfile

jsonfile is a simple module for reading and writing JSON files. It provides a straightforward API for interacting with JSON files in a Node.js environment. While 'jsonfile' focuses on file operations, 'json' provides command-line utilities for JSON manipulation.

json2csv

json2csv is a tool for converting JSON data to CSV format. It is useful for exporting JSON data into a more tabular format that can be used in spreadsheets and databases. Unlike 'json', which focuses on JSON manipulation, json2csv specializes in data format conversion.

README

json is a fast CLI tool for working with JSON. It is a single-file node.js script with no external deps (other than node.js itself). A quick taste:

$ echo '{"foo":"bar"}' | json
{
  "foo": "bar"
}

$ echo '{"foo":"bar"}' | json foo
bar

$ echo '{"fred":{"age":42}}' | json fred.age    # '.' for property access
42

$ echo '{"age":10}' | json -e 'this.age++'
{
  "age": 11
}

# `json -ga` (g == group, a == array) for streaming mode
$ echo '{"latency":32,"req":"POST /widgets"}
{"latency":10,"req":"GET /ping"}
' | json -gac 'this.latency > 10' req
POST /widgets

Features:

• pretty-printing JSON
• natural syntax (like JS code) for extracting particular values
• get details on JSON syntax errors (handy for config files)
• filter input JSON (see -e and -c options)
• fast stream processing
• JSON validation
• in-place file editing

See http://trentm.com/json for full docs and examples as a man page.

Follow @trentmick for updates to json.

Installation

1. Get node.

2. npm install -g json

   Note: This used to be called 'jsontool' in the npm registry, but as of version 8.0.0 it has taken over the 'json' name. See npm Package Name below.

OR manually:

1. Get the 'json' script and put it on your PATH somewhere (it is a single file with no external dependencies). For example:

    cd ~/bin
    curl -L https://github.com/trentm/json/raw/master/lib/json.js > json
    chmod 755 json
   

You should now have "json" on your PATH:

$ json --version
json 9.0.0

WARNING for Ubuntu/Debian users: There is a current bug in Debian stable such that "apt-get install nodejs" installed a nodejs binary instead of a node binary. You'll either need to create a symlink for node, change the json command's shebang line to "#!/usr/bin/env nodejs" or use chrislea's PPA as discussed on issue #56.

Test suite

make test

You can also limit (somewhat) which tests are run with the TEST_ONLY envvar, e.g.:

cd test && TEST_ONLY=executable nodeunit test.js

I test against node 0.4 (less so now), 0.6, 0.8, and 0.10.

License

MIT (see the fine LICENSE.txt file).

Module Usage

Since v1.3.1 you can use "json" as a node.js module:

var json = require('json');

However, so far the module API isn't that useful and the CLI is the primary focus.

npm Package Name

Once upon a time, json was a different thing (see zpoley's json-command here), and this module was called jsontool in npm. As of version 8.0.0 of this module, npm install json means this tool.

If you see documentation referring to jsontool, it is most likely referring to this module.

Alternatives you might prefer

• jq: http://stedolan.github.io/jq/
• json:select: http://jsonselect.org/
• jsonpipe: https://github.com/dvxhouse/jsonpipe
• json-command: https://github.com/zpoley/json-command
• JSONPath: http://goessner.net/articles/JsonPath/, http://code.google.com/p/jsonpath/wiki/Javascript
• jsawk: https://github.com/micha/jsawk
• jshon: http://kmkeen.com/jshon/
• json2: https://github.com/vi/json2

Changelog

9.0.2

• [pull #72] Correct examples in docs for conditional filtering.