fx

Command-line JSON processing tool

Features

• Don't need to learn new syntax
• Plain JavaScript
• Formatting and highlighting

Install

$ npm install -g fx

Usage

Pipe into fx any JSON and anonymous function for reducing it.

$ fx [code ...]

Pretty print JSON:

$ echo '{"key":"value"}' | fx
{
    "key": "value"
}

Use anonymous function:

$ echo '{"foo": [{"bar": "value"}]}' | fx "x => x.foo[0].bar"
"value"

If you don't pass anonymous function param => ..., code will be automatically transformed into anonymous function. And you can get access to JSON by this keyword:

$ echo '{"foo": [{"bar": "value"}]}' | fx "this.foo[0].bar"
"value"

You can pass any number of anonymous functions for reducing JSON:

$ echo '{"foo": [{"bar": "value"}]}' | fx "x => x.foo" "this[0]" "this.bar"
"value"

If passed code contains yield keyword, generator expression will be used:

$ curl ... | fx "for (let user of this) if (user.login.startsWith('a')) yield user"

Access to JSON through this keyword:

$ echo '["a", "b"]' | fx "yield* this"
[
    "a",
    "b"
]

$ echo '["a", "b"]' | fx "yield* this; yield 'c';"
[
    "a",
    "b",
    "c"
]

You can update existing JSON using spread operator:

$ echo '{"count": 0}' | fx "{...this, count: 1}"
{
    "count": 1
}

Convert object to array:

$ cat package.json | fx "yield* Object.keys(this.dependencies)"
[
    "cardinal",
    "get-stdin",
    "meow"
]

Related

• jq – cli JSON processor on C
• jsawk – like awk, but for JSON
• json – another JSON manipulating cli library

License

MIT