$ npm install jstdin --global

$ jstdin --help

  Usage:

    $ jstdin [code] [options]

  Description:

    executes javascript on the command line like `node -p`
    but also accepts data via stdin so long as [code] is wrapped
    with an anonymous function; it also formats output.

  Options:

    -r, --raw   prevent formatting output
    -h, --help  show this usage information

  Examples:

    # eval and print js (like node -p)
    $ jstdin '2*2'
    4

    # use stdin, process and pretty print
    $ echo '[1,2,3]' | jstdin 'x => x.map(x => x*2)'
    [
      2,
      4,
      6
    ]

    # use stdin, process and do not pretty print
    $ echo '[1,2,3]' | jstdin 'x => x.map(x => x*2)' --raw
    [2,4,6]

    # use stdin and just pretty print
    $ echo '[{"n":1,"a":{"b":"c"}},{"n":2,"a":{"d":{"e":"f"}}}]' | jstdin'
    [
      {
        "n": 1,
        "a": {
          "b": "c"
        }
      },
      {
        "n": 2,
        "a": {
          "d": "e"
        }
      }
    ]