Search code examples
jsonbashshellresponsejq

Check if response has error

I have some web API, which response with JSON, and a shell script, which sends requests with curl and processing JSON with jq.

Response structure is the following:

  • Error response: { "error": "error_message" } - single struct.
  • Good response: [ { "element1": "value1", "element2": "value2", "element3": "value3" } ] - array of structs of 3 elements (fixed amount).

The problem is that user may enter some data causing API response with the error. In this case, I won't be able to process the response as there is another structure.

I was trying to check if it's an error with echo ${json} | jq '. | select (.| has("error")) | has("error")', but this works only if it's an error response, if it's a "good" one - jq fails.

What should I do?

Solution

  • If you know that the responses are going to be of a specific type (an object vs an array), you could just test for that type.

    $ <<<"$json" jq 'arrays'  # "good" response
$ <<<"$json" jq 'objects' # "bad" response

    You could add additional checks as needed.