README.tutorial.md

Tutorial

Dive into the ejemplos (examples) folder to see things that you can do with jdva.

Example 01

Build a multidimensional array from an input JSON text and then print the result.

ejemplo_01.awk

@include "bbl_jdva.awk"

BEGIN {
    cad_json[0] = "";
    linea = "";

    while ((getline linea < ARGV[1]) > 0)
        cad_json[0] = cad_json[0] linea;
    close(ARGV[1]);

    jsonLstm(cad_json, lista);

    pinta(lista);
}

entrada.json

{
    "nombre":"Pedro",
    "edad":42,
    "ciudad":"Madrid",
    "datos":{
        "C.V.":"Computación"
    }
}

$ awk -f ./ejemplo_01.awk entrada.json
(nombre) = "Pedro"
(edad) = 42
(ciudad) = "Madrid"
(datos)(C.V.) = "Computación"

Example 02

Build a multidimensional array from an input JSON text, remove one element, and then print the result.

@include "bbl_jdva.awk"

BEGIN {
    cad_json[0] = "";
    linea = "";

    while ((getline linea < ARGV[1]) > 0)
        cad_json[0] = cad_json[0] linea;
    close(ARGV[1]);

    jsonLstm(cad_json, lista);
    quita(lista, "edad");

    pinta(lista);
}

entrada.json

{
    "nombre":"Pedro",
    "edad":42,
    "ciudad":"Madrid",
    "datos":{
        "C.V.":"Computación"
    }
}

$ awk -f ./ejemplo_02.awk entrada.json
(nombre) = "Pedro"
(ciudad) = "Madrid"
(datos)(C.V.) = "Computación"

Example 03

Build a multidimensional array from an input JSON text, modify one element, add new other one, and then print the result.

@include "bbl_jdva.awk"

BEGIN {
    cad_json[0] = "";
    linea = "";

    while ((getline linea < ARGV[1]) > 0)
        cad_json[0] = cad_json[0] linea;
    close(ARGV[1]);

    jsonLstm(cad_json, lista);
    pon(lista, "apellidos", "Blanco Crespo");
    pon(lista, "edad", 17);

    pinta(lista);
}

entrada.json

{
    "nombre":"Pedro",
    "edad":42,
    "ciudad":"Madrid",
    "datos":{
        "C.V.":"Computación"
    }
}

$ awk -f ./ejemplo_03.awk entrada.json
(nombre) = "Pedro"
(edad) = 17
(ciudad) = "Madrid"
(datos)(C.V.) = "Computación"
(apellidos) = "Blanco Crespo"

Example 04

Build a multidimensional array from an input JSON text, and then print the value of one of his element.

@include "bbl_jdva.awk"

BEGIN {
    cad_json[0] = "";
    linea = "";

    while ((getline linea < ARGV[1]) > 0)
        cad_json[0] = cad_json[0] linea;
    close(ARGV[1]);

    jsonLstm(cad_json, lista);

    print trae(lista, "nombre");
}

entrada.json

{
    "nombre":"Pedro",
    "edad":42,
    "ciudad":"Madrid",
    "datos":{
        "C.V.":"Computación"
    }
}

$ awk -f ./ejemplo_04.awk entrada.json
Pedro

Example 05

Build a multidimensional array from scratch, turn it into JSON text, and then print the result.

@include "bbl_jdva.awk"

BEGIN {
    cad_json[0] = "";
    
    delete lista;
    pon(lista, "nombre", "Pedro");
    pon(lista, "apellidos", "Blanco Crespo");
    pon(lista, "edad", 17);
    pon(lista, "ciudad", "Madrid");
    pon(lista, "datos.C\\.V\\.", "Computación");

    lstmJson(lista, cad_json);

    print cad_json[0];
}

$ awk -f ./ejemplo_05.awk
{"nombre":"Pedro","apellidos":"Blanco Crespo","edad":17,"ciudad":"Madrid","datos":{"C.V.":"Computación"}}

Example 06

Build a multidimensional array from scratch, turn it into JSON text, and then print (pretty print) the formatted result.

@include "bbl_jdva.awk"

BEGIN {
    cad_json[0] = "";
    
    delete lista;
    pon(lista, "nombre", "Pedro");
    pon(lista, "apellidos", "Blanco Crespo");
    pon(lista, "edad", 17);
    pon(lista, "ciudad", "Madrid");
    pon(lista, "datos.C\\.V\\.", "Computación");

    lstmJson(lista, cad_json);

    sangra(cad_json);
}

$ awk -f ./ejemplo_06.awk
{
    "nombre": "Pedro",
    "apellidos": "Blanco Crespo",
    "edad": 17,
    "ciudad": "Madrid",
    "datos": {"C.V.": "Computación"}
}

Example 07

Build a multidimensional array from an input JSON text, that contain one or more lists of coma separated elements beetwen brackets inside, and then get one of those elements referring it by its index. Arrays are one-based, so .[2] returns the second element.

entrada_con_listas.json

{
  "firstName": "John",
  "lastName": "Smith",
  "isAlive": true,
  "age": 27,
  "address": {
    "streetAddress": "21, 2nd Street",
    "city": "New York",
    "state": "NY",
    "postalCode": "10021-3100"
  },
  "phoneNumbers": [
    {
      "type": "home",
      "number": "212 555-1234"
    },
    {
      "type": "office",
      "number": "646 555-4567"
    },
    {
      "type": "mobile",
      "number": "123 456-7890"
    }
  ],
  "children": [],
  "spouse": null
}

$ cat entrada_con_listas.json |
> gawk -i bbl_jdva.awk '{
>   cad_json[0]=cad_json[0] $0;
> }
> END{
>   jsonLstm(cad_json, lista);
>   print trae(lista, "phoneNumbers.[3].number");
> }'
123 456-7890