Re: Light weight support for JSON

[Alex fxmbsw7 Ratchev]

On Sun, Aug 28, 2022, 15:25 Yair Lenga <yair.lenga@gmail.com> wrote:

> Hi,
>
> Over the last few years, JSON data becomes a integral part of processing.
> In many cases, I find myself having to automate tasks that require
> inspection of JSON response, and in few cases, construction of JSON. So
> far, I've taken one of two approaches:
> * For simple parsing, using 'jq' to extract elements of the JSON
> * For more complex tasks, switching to python or Javascript.
>
> Wanted to get feedback about the following "extensions" to bash that will
> make it easier to work with simple JSON object. To emphasize, the goal is
> NOT to "compete" with Python/Javascript (and other full scale language) -
> just to make it easier to build bash scripts that cover the very common use
> case of submitting REST requests with curl (checking results, etc), and to
> perform simple processing of JSON files.
>
> Proposal:
> * Minimal - Lightweight "json parser" that will convert JSON files to bash
> associative array (see below)
> * Convert bash associative array to JSON
>
> To the extent possible, prefer to borrow from jsonpath syntax.
>
> Parsing JSON into an associative array.
>
> Consider the following, showing all possible JSON values (boolean, number,
> string, object and array).
> {
>     "b": false,
>     "n": 10.2,
>     "s: "foobar",
>      x: null,
>     "o" : { "n": 10.2,  "s: "xyz" },
>      "a": [
>          { "n": 10.2,  "s: "abc", x: false },
>          {  "n": 10.2,  "s": "def" x: true},
>      ],
> }
>
> This should be converted into the following array:
>
> -------------------------------------
>
> # Top level
> [_length] = 6                            # Number of keys in object/array
> [_keys] = b n s x o a            # Direct keys
> [b] = false
> [n] = 10.2
> [s] = foobar
> [x] = null
>
> # This is object 'o'
> [o._length] = 2
> [o._keys] = n s
> [o.n] = 10.2
> [o.s] = xyz
>
> # Array 'a'
> [a._count] =  2                   # Number of elements in array
>
> # Element a[0] (object)
> [a.0._length] = 3
> [a.0._keys] = n s x
> [a.0.n] = 10.2
> [a.0.s] = abc
> [a.0_x] = false
>
> -------------------------------------
>
> I hope that example above is sufficient. There are few other items that are
> worth exploring - e.g., how to store the type (specifically, separate the
> quoted strings vs value so that "5.2" is different than 5.2, and "null" is
> different from null.
>

did you forget to send the script along ? or am i completly loss

a small thing i saw, a flat _keys doesnt do the job..

I will leave the second part to a different post, once I have some
> feedback. I have some prototype that i've written in python - POC - that
> make it possible to write things like
>
> declare -a foo
> curl http://www.api.com/weather/US/10013 | readjson foo
>
> printf "temperature(F) : %.1f Wind(MPH)=%d" ${foo[temp_f]}, ${foo[wind]}
>
> Yair
>