Command-line JSON processor cheatsheet

Read JSON input and format it

curl https://json-api-url | jq '.' 

or read input from the file

jq '.' file.json

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Accessing JSON properties

jq '.url'

Nested objects

jq '.committer.login'

To get multiple keys, separate them with comma

jq '.committer.login,.committer.type,.committer.url'

Wrap all retrieved properties in new object

jq '{login:.committer.login,type:.committer.type,url:.committer.url}'

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Formatting options

• -c --compact-output - do not pretty-print the output
• -r --raw-output - if the filter output is string, do not format as JSON string (no quotes)

Iterate over JSON array

jq '.[]'

Access element by index

jq '.[0]'

Display given element

jq '.[].element_name'

Slicing

Get elements 4-6

echo '[1,2,3,4,5,6,7,8,9,10]' | jq '.[3:6]'

Get first 5 elements

echo '[1,2,3,4,5,6,7,8,9,10]' | jq '.[:5]'

Get two last elements

echo '[1,2,3,4,5,6,7,8,9,10]' | jq '.[-2:]'

Get 3rd from the back

echo '[1,2,3,4,5,6,7,8,9,10]' | jq '.[-3]'

Array length

jq 'length'

Keys

jq 'keys'

Minimum

jq '[.[].price] | min'

Maximum

jq '[.[].price] | max'

Select elements

jq 'select(.Verified == true)'

Multiple conditions

jq 'select((.status_code == 200) and (.content_type == "application/json"))'

Pass output of the one filter to another, build an object from those fields

jq '.[] | {message: .commit.message, name: .commit.committer.name}'

Build an array of the objects from the filter

jq '[.[] | {message: .commit.message, name: .commit.committer.name}]'

JSONL to JSON

jq -s '.' input.jsonl > output.json

JSON to JSONL

jq -c '.[]' input.json > output.jsonl