Structured data#

Bashkit ships structured-data builtins for the formats scripts hit most often. jq and yq share one jq-compatible transformation engine; narrower helpers cover common CSV, JSON, and TOML operations. All read files or stdin.

Builtin	Format	Reach for it when
jq	JSON	You need real JSON transformation — filters, construction, reduction.
yq	YAML / JSON	You want the same jq expressions over YAML, conversion, or safe in-place updates.
json	JSON	You want a quick get / set / keys / length without jq syntax.
csv	CSV	Selecting columns, filtering rows, counting, sorting tabular data.
tomlq	TOML	Reading a value out of Cargo.toml, pyproject.toml, etc.

csv#

Subcommands: select, count, headers, filter, sort. Use -d for a custom delimiter and --no-header for headerless data.

csv select name,age data.csv      # project columns
csv filter age = 30 data.csv      # rows where age == 30
csv sort name data.csv            # sort by column
csv count data.csv                # row count
csv headers data.csv              # list column names
echo "alice,30" | csv --no-header count

json#

A lighter alternative to jq for everyday access. Subcommands: get, set, keys, length, type, format, pretty.

echo '{"a":1}'     | json get .a       # 1
echo '{"a":1}'     | json set .b 2      # {"a":1,"b":2}
echo '{"a":1,"b":2}' | json keys        # a, b
echo '[1,2,3]'     | json length        # 3
echo '{"a":1}'     | json format        # pretty-print

yq#

Use jq-style expressions over YAML or JSON. The jq Cargo feature enables it. YAML mapping keys are emitted in deterministic sorted order; source order, comments, styles, and anchors are not preserved. Custom tags, non-string keys, and non-finite numbers fail closed at the JSON-value boundary.

yq '.server.port' config.yml
yq '.items[] | select(.enabled) | .name' config.yml
yq -o=json -I=0 config.yml
yq -i '.server.port = 8080' config.yml

tomlq#

Query TOML by dot-separated path. -r emits raw (unquoted) string values.

tomlq server.port config.toml
tomlq -r dependencies.serde.version Cargo.toml
cat config.toml | tomlq server.port

Composing them#

Because every builtin reads stdin, they pipe into each other and into the text tools:

# CSV → JSON-ish summary
csv select name,price products.csv | csv sort price

# Pull a value out of config, then use it
port=$(yq '.server.port' config.yml)
echo "starting on $port"

See also#

• jq builtin — the full JSON query engine, with its own compatibility reference.
• yq builtin — YAML/JSON flags, in-place behavior, and explicit gaps.
• Compatibility — the complete builtin coverage matrix.
• Browse all builtins — every registered command.