xx

README

fx-like command-line JSON processing tool

Features

• Don't need to learn new syntax
• Written in Go
• Formatting and highlighting

Differences

• Only ES5 (no arrow functions, no spread)
• Small binary size (xx ~5mb vs fx ~30mb)
• Can't use npm packages

Install

$ go get github.com/antonmedv/xx

Or download precompiled binary from releases page.

Usage

Pipe into xx any JSON and JS code for reducing it.

$ xx [code ...]

Pretty print JSON without passing any arguments:

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

This Binding

You can get access to JSON by this keyword:

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

Chain

You can pass any number of code blocks for reducing JSON:

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

Formatting

If you need something different then JSON (for example arguments for xargs) do not return anything from reducer. undefined value printed into stderr by default.

$ echo '[]' | xx 'void 0'
undefined

$ echo '[1,2,3]' | xx 'this.forEach(function (x) { console.log(x) })' 2>/dev/null | xargs echo
1 2 3

Modifying

To modify object use command separated by comma , and return this as the end.

$ echo '{"a": 2}' | xx 'this["b"] = Math.pow(this.a, 10), this'
{
  "a": 2,
  "b": 1024
}

Object keys

Get all object keys:

$ echo '{"foo": 1, "bar": 2}' | xx 'Object.keys(this)'
[
  "foo",
  "bar"
]

By the way, xx has shortcut for Object.keys(this). Previous example can be rewritten as:

$ echo '{"foo": 1, "bar": 2}' | xx ?

Dot

It is possible to omit this keyword:

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

Related

• fx – original fx package
• ymlx - fx-like YAML cli processor

License

MIT