I am trying to update an value for a key based on a select filter. The list contains dictionaries with same key names, but different values. Based on value, I am filtering to select a dictionary and then update the sibling key in it.

The value update works, but the dictionaries move out of list as expected because of .[], but how do I add them back to the list. Or, how can I do it without using .[]?

Input List:

[
    {
        "key1": "a",
        "key2": "b"
    },
    {
        "key1": "c",
        "key2": "d"
    },
    {
        "key1": "d",
        "key2": "e"
    }
]

Command I am running: jq --arg temp "f" '.[] | select( .key1 == "c").key2 |= $temp' test.json

output:

{
  "key1": "a",
  "key2": "b"
}
{
  "key1": "c",
  "key2": "f"
}
{
  "key1": "d",
  "key2": "e"
}

The objects are not part of list now. Expected output:

[
    {
        "key1": "a",
        "key2": "b"
    },
    {
        "key1": "c",
        "key2": "f"
    },
    {
        "key1": "d",
        "key2": "e"
    }
]

How can we add the objects back to a list, or do it in-place.

CodePudding user response：

Use map() to keep the original structure:

jq --arg temp  "f" 'map(select( .key1 == "c").key2 |= $temp)' test.json

Online demo

CodePudding user response：

You could also just use another pair of parentheses around the left hand side of the update assignment in order to retain the context:

Either way works:

jq --arg temp "f" '(.[] | select(.key1 == "c").key2) |= $temp' test.json

Demo

jq --arg temp "f" '(.[] | select(.key1 == "c")).key2 |= $temp' test.json

Demo