jq, Built-in JSON Processor

Crush ships a built-in jq command (via github.com/itchyny/gojq) available in the bash tool. No external binary is required.

Supported Flags

Flag	Description
-r, --raw-output	Output strings without quotes
-j, --join-output	Like -r but no trailing newline
-c, --compact-output	One-line JSON output
-s, --slurp	Read all inputs into an array
-n, --null-input	Use null as input (ignore stdin)
-e, --exit-status	Exit 1 if last output is false or null
-R, --raw-input	Read each line as a string, not JSON
--arg name value	Bind $name to a string value
--argjson name value	Bind $name to a parsed JSON value

File arguments after the filter are also supported: jq '.foo' file.json.

Differences from Standard jq

The built-in uses gojq, which is a pure-Go jq implementation. Key differences:

• No object key ordering, keys are sorted by default; keys_unsorted and -S are unavailable.
• Arbitrary-precision integers, large integers keep full precision (addition, subtraction, multiplication, modulo, division when divisible).
• String indexing, "abcde"[2] returns "c".
• Not supported, --ascii-output, --seq, --stream, --stream-errors, -f/--from-file, --slurpfile, --rawfile, --args, --jsonargs, input_line_number, $__loc__, some regex features (backreferences, look-around).
• YAML, gojq supports --yaml-input/--yaml-output but the built-in does not currently expose these flags.

Common Patterns

Extract a field:

echo '{"name":"crush"}' | jq '.name'

Filter an array:

echo '[1,2,3,4,5]' | jq '[.[] | select(. > 3)]'

Reshape objects:

echo '{"first":"Ada","last":"Lovelace"}' | jq '{full: (.first + " " + .last)}'

Use variables:

echo '{}' | jq --arg host localhost --argjson port 8080 '{host: $host, port: $port}'