jq is a lightweight and flexible command-line JSON processor. It is like sed for JSON data - you can use it to slice and filter and map and transform structured data with the same ease that sed, awk, grep and friends let you play with text.
Installation
brew install jq
Common Usage Examples
1. Prettify JSON
Format JSON output to be readable:
echo '{"foo": "bar"}' | jq .
2. Extract a Value
Get the value of a specific key:
echo '{"foo": "bar"}' | jq '.foo'
# Output: "bar"
3. Filter Array
Process elements in an array:
echo '[{"id":1}, {"id":2}]' | jq '.[].id'
# Output:
# 1
# 2
4. Select Objects
Filter objects based on a condition:
echo '[{"id":1, "active":true}, {"id":2, "active":false}]' | jq '.[] | select(.active==true)'
5. Construct New JSON
Create a new JSON structure from input:
echo '{"user":"navy", "age":30}' | jq '{name: .user, year: .age}'
# Output: { "name": "navy", "year": 30 }