JQ and you!

Tool for parsing JSON objects from CLI

If you work with CLI tools dealing with API calls, chances are you might have been dumped with huge payload response; and want to pick selected parts of it. Enter JQ —JSON object parser CLI utility using JMESPath syntax. This is a game-changer if the API call doesn’t support native JMESPath syntax to fetch selected objects. If you use AWS CLI, I have a few examples below:

Getting started

1. Install JQ — https://stedolan.github.io/jq/download/
2. Start parsing JSON objects with jq!

Basics:

• Get JSON data from curl and parse it with jq:

curl -s https://httpbin.org/get | jq .
{                       
  "args": {},
  "headers": {
    "Accept": "*/*",
    "Host": "httpbin.org",
    "User-Agent": "curl/7.63.0",
    "X-Amzn-Trace-Id": "Root=1-5ead7fda-d6634b572db4237f4485907d"
  },
  "origin": "109.78.73.8",
  "url": "https://httpbin.org/get"
}

• Get length of the object:

curl -s https://httpbin.org/get | jq length
4

• Get all keys from the response:

curl -s https://httpbin.org/get | jq keys
[
  "args",
  "headers",
  "origin",
  "url"
]

• Get the value of all keys from the response:

curl -s https://httpbin.org/get | jq ".[]"
{}
{
  "Accept": "*/*",
  "Host": "httpbin.org",
  "User-Agent": "curl/7.61.1",
  "X-Amzn-Trace-Id": "Root=1-5ead8a59-8ec68bb6ff6d7a58d2883c54"
}
"54.212.64.144"
"https://httpbin.org/get"

• Get all headers values from a specific key:

curl -s https://httpbin.org/get | jq ".headers"
{
  "Accept": "*/*",
  "Host": "httpbin.org",
  "User-Agent": "curl/7.61.1",
  "X-Amzn-Trace-Id": "Root=1-5ead897c-654f503422187fb4553e1d20"
}

• Get values from multiple keys:

curl -s https://httpbin.org/get | jq ".headers,.url"
{
  "Accept": "*/*",
  "Host": "httpbin.org",
  "User-Agent": "curl/7.61.1",
  "X-Amzn-Trace-Id": "Root=1-5ead8b0f-702f31eead4dd61cba35d6ea"
}
"https://httpbin.org/get"