To keep things simple, I have that file.js:

{
    "devices": [
      {
        "label": "label1",
        "percent": 10
      },
      {
        "label": "label2",
        "percent": 20
      }
    ]
 }

Since I browsed Google and StackOverflow a lot, I actually know how to update, let's say, the label2 from 20% to 50% :

jq '.devices[] | select(.label == "label2").percent = 50' file.json

But here's the ouput:

{
  "label": "label1",
  "percent": 10
}
{
  "label": "label2",
  "percent": 50
}

The devices object (?) is not there anymore.

I'd like to find a way to keep the exact same input format. I guess I should rid of the pipe, but I don't know how. I've browsed Google and I found the to_entries / with_entries / from_entries, that seem to keep the whole thing, but I don't know how to merge eveything together.

Thank you.

CodePudding user response：

Make the traversal and filtering all part of the assignment's LHS using parentheses:

jq '(.devices[] | select(.label == "label2").percent) = 50' file.json

Demo

Alternatively, update |= to a map of the whole .devices array:

jq '.devices |= map(select(.label == "label2").percent = 50)' file.json

Demo

Output:

{
  "devices": [
    {
      "label": "label1",
      "percent": 10
    },
    {
      "label": "label2",
      "percent": 50
    }
  ]
}