How to extract a field from each object in an array with jq?

Question

I performed a cURL request to get all the users in our Gitlab server, like this.

$ curl -H "Private-Token: a;sldkfja;slkdfj" https://gitlab.domain.com/api/v3/users?active=true > my_file.json

and (part of) my_file.json looks like:

[
  {
    'username' : 'jdoe',
    'name' : 'John Doe',
    ...
  },
  {
    'username' : 'jadoe',
    'name' : 'Jane Doe',
    ...
  }
]

I stored the response in my_file.json. How can I use jq to get all the username values?

$ cat my_file.json | jq -r 'what to put here?'

If that is what the actual cURL response or contents of your file looks like, you do not have valid JSON. — JAAulde, Jan 24 '18 at 15:35
You showed us the source data, what are you wanting the output data to look like? — JAAulde, Jan 24 '18 at 15:38
@JAAulde, I want an output that can let me parse all the usernames easily. — Chris F, Jan 24 '18 at 15:53
Your stated goal is entirely too subjective. Please provide a sample format of desired output in your question. — JAAulde, Jan 24 '18 at 16:24
I don't think this is a bad request at all. The precise output format doesn't matter - he's obviously trying to grapple with the jq syntax to (as the title says) "extract a field from each object in an array". The accepted answerer clearly figured out what he (and I) wanted. — fool4jesus, Jun 28 '19 at 12:09

John Kugelman · Accepted Answer · 2018-01-24T17:48:22.600

92

$ jq -r '.[].username' my_file.json
jdoe
jadoe

edited Jan 24 '18 at 17:48

answered Jan 24 '18 at 15:54

John Kugelman

1 Answers1