Can you print the values of a JSON array in an AWS, using a JMESPath query?

I am trying to list all the SQS queues in our account using aws sqs list-queues into a bash one-item-per-line output.

Problem is it comes through as a JSON object

{
  "QueueUrls": [
    "url",
    "url",
    "etc..."
  ]
}

I can use JMESpath to get this aws sqs list-queues --query 'QueueUrls[]'

but that gives me:

[
   "url",
   "url",
   "etc..."
]

Question

Is it possible to print the output from a JSON array, using a JMESPath query in a one-per-line style?

From:

{
  "key": [
    "string",
    "string",
    "string"
  ]
}

To:

string
string
string

I want:

url
url
url

Using aws sqs list-queues --query 'QueueUrls[]' --output text

I get the urls all in one line:
```
url   url   url   etc...
```
I've also looked at this other question but nothing I tried to put into the query gave me the flat-output

Currently I'm doing aws sqs list-queues --output text | sed -E 's/^.+\s+(.+)$/\1/' to extract the url line from the text output.

(Definitely also posible with awk but the sed regex was the thing my mind did first)

I want to use the output in a bash script I'm writing. I want to grep the lines and do some other processing on the output.

In this case it was simple to do the --output text trick but for more complicated AWS objects I'd like to know if it is possible using JMESPath.

Solution

You can achieve this by joining the elements of the JSON array with the join bulletin function.

You have two possible and equivalent syntaxes:

Chaining the function on the array, and using the current node — @
```
QueueUrls.join(`\n`, @)
```
Wrapping the whole array in the function
```
join(`\n`, QueueUrls)
```

^{Note: backticks — `, in JMESPath is the delimiter for a literal expression.}

So, your AWS command ends up being:

aws sqs list-queues --query 'QueueUrls.join(`\n`, @)' --output text