README.md

jpl

Command line JSON parser, processor that takes plain JavaScript.

jpl is similar to jq in that it's a command line tool used to work with JSON. jpl differs from jq in that it takes plain JavaScript code in order to do any processing, reducing, filtering, etc.

Installation

Note: jpl requires requires Node.js v8.0.0 or later.

npm install -g jpl

Usage

$ jpl --help

  Usage: jpl [options]


  Options:

    -V, --version      output the version number
    -c, --code <code>  Function to execute to parse JSON
    -h, --help         output usage information

Examples

Parse JSON and Format

If you're interested in just formatting some (valid) JSON, pipe the file to jpl.

$ < example.json jpl
{
  "data": [
    {
      "foo": "bar",
      "bar": "foo"
    },
    {
      "foo": "foobar",
      "bar": "barfoo"
    },
    {
      "bar": "foo"
    }
  ]
}

Process parsed JSON with JavaScript function

Using the previous example's JSON file as the same input, we can also do some work on the file by simply passing some JavaScript to jpl via the -c (or --code) flag.

jpl's -c/--code argument expects a function that takes one argument, which will be the JSON Object.

$ < example.json jpl -c "({ data }) => data.filter(({ foo }) => foo)"
[
  {
    "foo": "bar",
    "bar": "foo"
  },
  {
    "foo": "foobar",
    "bar": "barfoo"
  }
]

You can also chain jpl calls like anything else:

$ < example.json jpl -c '({ data }) => data' \                                                                                                  <<<
  | jpl -c 'd => d.filter(({ foo }) => foo)' \
  | jpl -c 'd => `${d.length} array elements have a truthy "foo" key value`'
"2 array elements have a truthy \"foo\" key value"