$ gojo foo=bar qux=quux
{"foo":"bar","qux":"quux"}
 $ gojo -p foo=bar qux=quux
{
  "foo": "bar",
  "qux": "quux"
}
 $ gojo -a foo bar baz
["foo","bar","baz"]
 $ seq 10 | gojo -a
[1,2,3,4,5,6,7,8,9,10]
 $ gojo -p foo=$(gojo bar=$(gojo baz=100))
{
  "foo": {
    "bar": {
      "baz": 100
    }
  }
}
 $ gojo -p foo[bar][baz][qux][quux]=128
{
  "foo": {
    "bar": {
      "baz": {
        "qux": {
          "quux": 128
        }
      }
    }
  }
}
 $ gojo -p res[foo][][id]=10 res[foo][][id]=20 res[cnt]=2
{
  "res": {
    "foo": [
      {
        "id": 10
      },
      {
        "id": 20
      }
    ],
    "cnt": 2
  }
}
 $ gojo foo=@Makefile  # read contents from file
{"foo":"BIN := gojo\nCURRENT_REVISION := $(shell git rev-parse --short HEAD)\nBUILD_LDFLAGS := \"-X ..."}
 $ gojo foo=%Makefile  # base64 of file contents
{"foo":"QklOIDo9IGdvam8KQ1VSUkVOVF9SRVZJU0lPTiA6PSAkKHNoZWxsIGdpdCByZXYtcGFyc2UgLS1zaG9ydCBIRUFEKQp ..."}

brew install itchyny/tap/gojo

go get -u github.com/itchyny/gojo/cmd/gojo