meallhour meallhour - 2 months ago 17
Bash Question

Using jq to fetch key value from json output

I have a file that looks as below:

{
"repositories": [
{
"id": "156c48fc-f208-43e8-a631-4d12deb89fa4",
"namespace": "rhel12",
"namespaceType": "organization",
"name": "rhel6.6",
"shortDescription": "",
"visibility": "public"
},
{
"id": "f359b5d2-cb3a-4bb3-8aff-d879d51f1a04",
"namespace": "rhel12",
"namespaceType": "organization",
"name": "rhel7",
"shortDescription": "",
"visibility": "public"
}
]
}


I want to get only name values with each of them in a new line so that I can use
while read -r line
.
I need only

rhel6.6
rhel7


I am using jq as follows which doesn't seem to work:

jq -r '.[].name'


Please suggest correct use of jq here

Answer

You need to combine filters by means of | operator:

$ jq -r '.[] | .[] | .name' test.json 
rhel6.6
rhel7

The first .[] fetches repositories array. The next .[] fetches all the items of the repositories array. Finally, .name extracts properties from the array items(objects).

Note, the first .[] works on object because it is a documented feature:

.[]
    If you use the .[index] syntax, but omit the index entirely, it
    will return all of the elements of an array...

    You can also use this on an object, and it will return all the
    values of the object.