# JQ

## Piping into jq

You can `cat` or `bat` a file and pipe it into `jq`.

You can also take a command that returns json and pipe it into `jq`.

## Returning data without "

To return data without `jq` wrapping results in `"` use the `-r` flag.

`jq -r`

## Filtering

### Get values from a key

Running `aws --profile admin cloudformation describe-stack-resources --stack-name strapi-vpc | jq` returns:

```json
{
  "StackResources": [
    {
      "StackName": "strapi-vpc",
      "StackId": "arn:aws:cloudformation:eu-west-1:745437999005:stack/strapi-vpc/a9e41430-8afc-11ea-bdaa-0a736ea8438a",
      "LogicalResourceId": "InternetGateway",
      "PhysicalResourceId": "igw-0e059db8e0795ac32",
      "ResourceType": "AWS::EC2::InternetGateway",
      "Timestamp": "2020-04-30T16:07:42.434Z",
      "ResourceStatus": "CREATE_COMPLETE",
      "DriftInformation": {
        "StackResourceDriftStatus": "NOT_CHECKED"
      }
    },
    {
      "StackName": "strapi-vpc",
      "StackId": "arn:aws:cloudformation:eu-west-1:745437999005:stack/strapi-vpc/a9e41430-8afc-11ea-bdaa-0a736ea8438a",
      "LogicalResourceId": "InternetGatewayAttachment",
      "PhysicalResourceId": "strap-Inter-1413K0IDR1L3N",
      "ResourceType": "AWS::EC2::VPCGatewayAttachment",
      "Timestamp": "2020-04-30T16:08:00.147Z",
      "ResourceStatus": "CREATE_COMPLETE",
      "DriftInformation": {
        "StackResourceDriftStatus": "NOT_CHECKED"
      }
    },
```

We can then use `jq`'s filtering to return values.

We have a key of `StackResources` which contains a list: `.StackResources[]`

We can then pass in the key we want `.StackResources[].PhysicalResourceId`

`aws --profile admin cloudformation describe-stack-resources --stack-name strapi-vpc | jq -r '.StackResources[].PhysicalResourceId'` which gives:

```json
"igw-0e059db8e0795ac32"
"strap-Inter-1413K0IDR1L3N"
"strap-Publi-1TS82BV8W4UFD"
"rtb-0cf8d05f71a30ef03"
"subnet-051fe56dc37d8396d"
"rtbassoc-0f7ae2fbdfe6bf2a5"
"subnet-0ea9f2f165a57be27"
"rtbassoc-00a67937c3778e273"
"subnet-09b28d722f41b2dde"
"rtbassoc-0a0a6bd0f8ff641df"
"vpc-029d232726cbf591d"
```

`aws --profile admin cloudformation describe-stack-resources --stack-name strapi-vpc | jq -r '.StackResources[] | .ResourceType + ":    " + .PhysicalResourceId'`