jq: print key and value for each entry in an object

Question

To get the top-level keys as a stream, you can use the built-in function keys[]. So one solution to your particular problem would be:

jq -r 'keys[] as $k | "\($k), \(.[$k] | .ip)"'

keys produces the key names in sorted order; if you want them in the original order, use keys_unsorted.

Another alternative, which produces keys in the original order, is:

jq -r 'to_entries[] | "\(.key), \(.value | .ip)"'

The @csv and @tsv filters might also be worth considering here, e.g.

jq -r 'to_entries[] | [.key, .value.ip] | @tsv'

produces:

host1   10.1.2.3
host2   10.1.2.2
host3   10.1.18.1

If the keys of interest are embedded as in the following example, the jq filter would have to be modified along the lines shown.

Input:

{
  "myhosts": {
    "host1": { "ip": "10.1.2.3" },
    "host2": { "ip": "10.1.2.2" },
    "host3": { "ip": "10.1.18.1" }
  }
}

Modification:

jq -r '.myhosts | keys[] as $k | "\($k), \(.[$k] | .ip)"'