How to use jq to find all paths to a certain key

Question

In a very large nested json structure I\'m trying to find all of the paths that end in a key.

ex:

{
  \"A\": {
    \"A1\": {
      \"foo\": {
               


        

Answer 1

With your input:

$ jq -c 'paths | select(.[-1] == "foo")' 
["A","A1","foo"]
["foo"]

Bonus points:

(1) If your jq has tostream:

$ jq 'fromstream(tostream| select(.[0]|index("foo")))'

Or better yet, since your input is large, you can use the streaming parser (jq -n --stream) with this filter:

fromstream( inputs|select( (.[0]|index("foo"))))

(2) Whether or not your jq has tostream:

. as $in
| reduce (paths(scalars) | select(index("foo"))) as $p
    (null; setpath($p; $in|getpath($p)))

In all three cases, the output is:

{
  "A": {
    "A1": {
      "foo": {
        "_": "_"
      }
    }
  },
  "foo": {
    "_": "_"
  }
}