change json file by bash script

Question

I need your help to solve the following problem: I have a JSON file that looks like this:

{
  \"key1\": \"value1\",
  \"key2\": \"value2\",
  \"key3\": \"val         


        

Answer 1

how can I add and remove a new key (i.e "key4": "value4") by bash script?

Using a dedicated JSON tool, like Xidel, would be a better idea than to use pure Bash functions.

Add a new attribute-value pair:

Dot notation:

echo '{"a":1,"b":2,"c":3}' | xidel -s - -e '($json).d:=4'
{
  "d": 4,
  "a": 1,
  "b": 2,
  "c": 3
}

JSONiq:

echo '{"a":1,"b":2,"c":3}' | xidel -s - -e '{|$json,{"d":4}|}'
{
  "a": 1,
  "b": 2,
  "c": 3,
  "d": 4
}

XQuery 3.1 (requires Xidel 0.9.9-beta):

echo '{"a":1,"b":2,"c":3}' | xidel -s - -e 'map:put($json,"d",4)'
{
  "d": 4,
  "a": 1,
  "b": 2,
  "c": 3
}

echo '{"a":1,"b":2,"c":3}' | xidel -s - -e 'map:merge(($json,{"d":4}))'
{
  "a": 1,
  "b": 2,
  "c": 3,
  "d": 4
}

Remove the attribute-value pair "d":4:

JSONiq:

echo '{"a":1,"b":2,"c":3,"d":4}' | xidel -s - --xmlns:jnlib="http://jsoniq.org/function-library" -e 'jnlib:remove-keys($json,"d")'
{
  "a": 1,
  "b": 2,
  "c": 3
}

XQuery 3.1 (requires Xidel 0.9.9-beta):

echo '{"a":1,"b":2,"c":3,"d":4}' | xidel -s - -e 'map:remove($json,"d")'
{
  "a": 1,
  "b": 2,
  "c": 3
}