jq - How to iterate through keys of different names

Question

I've got JSON that looks like this

{
  "keyword1": {
    "identifier1": 16
  },
  "keyword2": {
    "identifier2": 16
  }
}

and I need to loop through the keywords to get the identifiers (not sure if I'm using the right terminology here). Seems pretty simple, but because the keywords are all named different, I don't know how to handle that.

Please specify what you want the output to look like. – Mark Reed Jan 30 '16 at 04:09 — Mark Reed, Jan 30 '16 at 04:09
Just like the answer from peak – Adam vonNieda Feb 01 '16 at 02:25 — Adam vonNieda, Feb 01 '16 at 02:25

peak · Accepted Answer · 2020-08-10T01:16:37.943

51

The original tag for this question was jq so here is a jq solution:

.[] | keys[]

For example, with the input as shown in the question:

$ jq '.[] | keys[]' input.json

"identifier1"
"identifier2"

To retrieve the key names in the order they appear in the JSON object, use keys_unsorted.

edited Aug 10 '20 at 01:16

answered Jan 29 '16 at 18:25

peak

105,803
17
152
177

Neat, I didn't know that you could turn an object into an array with `[]`. – Mark Reed Feb 01 '16 at 14:21

score 27 · Answer 2 · answered May 28 '20 at 23:18

27

I'd think something along these lines would work well:

jq '. | to_entries | .[].key'

see https://stedolan.github.io/jq/manual/#to_entries,from_entries,with_entries

or if you wanted to get the values from a variable:

JSON_DATA={main:{k1:v1,k2:v2}}
result=$(jq -n "$JSON_DATA" | jq '.main | to_entries | .[].value' --raw-output)
echo $result

##outputs: v1 v2

answered May 28 '20 at 23:18

bristweb

948
14
14

1

Usage of `to_entries` was very helpful! – Mark Schäfer Jul 21 '20 at 09:04

score 5 · Answer 3 · answered Jan 08 '19 at 00:57

I came here hoping to sort out a bunch of keys from my JSON, I found two features handy. There are three functions "to_entries", "from_entries", and "with_entries". You can filter the values by key or value, like so:

JSON_DATA='
{
  "fields": {
    "first": null,
    "second": "two",
    "third": "three"
  }
}
'

echo "$JSON_DATA" | jq '{fields: .fields | with_entries(select(.value != null and .key != "third")) }'

Output:

{
  "fields": {
    "second": "two"
  }
}

Oleg P. Philon · Answer 4 · 2023-02-07T17:57:09.770

simpler solution - just treat internal hash as a new hash and add one more filter. The query that helped me:

$ docker network inspect bridge|jq '.[].Containers'
{
  "35c9e1273c43db01c45b5f43f6999d04c18beff3996ea09fb8b87a8b635c38ff": {
    "Name": "nginx",
    "EndpointID": "a6e788d6f90eb14df2321a2eb02517f0862c1fe7fe50c02f2b8c103c0c79cb6b",
    "MacAddress": "02:42:ac:11:00:02",
    "IPv4Address": "172.17.0.2/16",
    "IPv6Address": ""
  },
  "b46c157cec243969f9227251dfd6fa65b7a904e145df80a63f79d4dc8b281355": {
    "Name": "sweet_gates",
    "EndpointID": "a600d9c1ee35b9f7db31249ae8f589c202e0b260e10a394757a88bfd66b5b42f",
    "MacAddress": "02:42:ac:11:00:03",
    "IPv4Address": "172.17.0.3/16",
    "IPv6Address": ""
  }
}

As I needed only couple of fields, add to above .json one more query:

$ docker network inspect bridge|jq -jr '.[].Containers[]|.IPv4Address, "\t", .Name, "\n"'
172.17.0.2/16   nginx
172.17.0.3/16   sweet_gates

jq - How to iterate through keys of different names

4 Answers4