tldr/pages/common/jq.md

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jq

A command-line JSON processor that uses a domain-specific language. More information: https://stedolan.github.io/jq.

  • Output a JSON file, in pretty-print format:

jq . {{file.json}}

  • Output all elements from arrays (or all the values from objects) in a JSON file:

jq '.[]' {{file.json}}

  • Output elements from arrays which match provided filter:

jq '.[] | select(.{{key_name}} == {{value}})'

  • Read JSON objects from a file into an array, and output it (inverse of jq .[]):

jq --slurp . {{file.json}}

  • Output the first element in a JSON file:

jq '.[0]' {{file.json}}

  • Output the value of a given key of each element in a JSON text from stdin:

cat {{file.json}} | jq 'map(.{{key_name}})'

  • Output the value of multiple keys as a new JSON object (assuming the input JSON has the keys key_name and other_key_name):

cat {{file.json}} | jq '{{{my_new_key}}: .{{key_name}}, {{my_other_key}}: .{{other_key_name}}}'

  • Output the value of a given key to a string (and disable JSON output):

cat {{file.json}} | jq --raw-output '"some text: \(.{{key_name}})"'