Change all keys in yaml file to lowercase

[0byt3]

The syntax on how to recurse and then manipulate the key name is not clicking with me.
The following works for the first keys, so I thought I could use it recursively somehow.

yq -N -o yml '. | with_entries(.key |= downcase)' test.yml

I have got this far:

yq -N -o yml '(.. | select(type == "!!map")) | with_entries(.key |= downcase)' test.yml

However it doesn't produce the correct results.

file:

key_one: "<password>"

key_two: "<username>"

KEY_three:
  key_a:
    Key_i: "val_three_a_i"
    key_ii: "val_three_a_ii"

  key_B:
    key_i: "val_three_b_i"
    key_I: "val_three_b_ii"

  key_c:
    key_i: "val_three_a_i"
    key_I: "val_three_a_ii"

output:

key_one: "<password>"
key_two: "<username>"
key_three:
  key_a:
    Key_i: "val_three_a_i"
    key_ii: "val_three_a_ii"
  key_B:
    key_i: "val_three_b_i"
    key_I: "val_three_b_ii"
  key_c:
    key_i: "val_three_a_i"
    key_I: "val_three_a_ii"
key_a:
  Key_i: "val_three_a_i"
  key_ii: "val_three_a_ii"
key_b:
  key_i: "val_three_b_i"
  key_I: "val_three_b_ii"
key_c:
  key_i: "val_three_a_i"
  key_I: "val_three_a_ii"
key_i: "val_three_a_i"
key_ii: "val_three_a_ii"
key_i: "val_three_b_i"
key_i: "val_three_b_ii"
key_i: "val_three_a_i"
key_i: "val_three_a_ii"

[mikefarah]

You're very close, the reason you're getting that is because '..' expands to match all nodes - and then you are running the remaining expressions on that expansion. What you want to do is have the expansion as a LHS parameter of an update function, to just run an update on all the matches.

yq '(.. | select(type == "!!map")) |= with_entries(.key |= downcase)' examples/data1.yaml

So now it finds all the maps, and for every map it will replace it with the calculation from with_entries.

Going to add an example to the entries doc

[mikefarah]

Added new example: https://mikefarah.gitbook.io/yq/operators/entries#use-with_entries-to-update-keys-recursively