jarq

An interactive jq-like JSON query tool with a TUI.

Should you use this instead of jq? Definitely not, this was just an experiment using a TUI and live filtering.

Usage

# Interactive TUI mode
echo '{"name": "Alice", "age": 30}' | jarq
cat data.json | jarq
jarq data.json

# Non-interactive mode (like jq)
echo '{"name": "Alice"}' | jarq '.name'
jarq '.items[]' data.json

In interactive mode, type filter expressions and see results in real-time.

Keyboard Controls

Navigation Mode

Key	Action
`i`, `/`	Enter filter edit mode
`j`, `↓`	Scroll down
`k`, `↑`	Scroll up
`g`	Go to top
`G`	Go to bottom
`Ctrl-D`	Page down
`Ctrl-U`	Page up
`s`	Toggle slurp mode
`r`	Toggle raw output
`o`	Toggle compact output
`y`	Copy filter as jq command
`q`, `Esc`	Quit
`Ctrl-H`	Show help

Filter Edit Mode

Key	Action
`Esc`	Exit filter edit mode
`Ctrl-P`	Toggle pause/resume evaluation
`Ctrl-C`	Cancel running evaluation
`Enter`	Evaluate now (when paused)
`Ctrl-S`	Toggle slurp mode
`Ctrl-R`	Toggle raw output
`Ctrl-O`	Toggle compact output
`Ctrl-Y`	Copy filter as jq command
`Ctrl-H`	Show help

Background Evaluation

jarq evaluates filters in the background as you type. For large files, you can:

Pause evaluation (Ctrl-P): Stop auto-evaluation while you compose a complex filter
Cancel evaluation (Ctrl-C): Stop a long-running evaluation and enter pause mode
Evaluate on demand (Enter): When paused, manually trigger evaluation

When paused, the filter is still validated for syntax errors in real-time.

Filter Syntax

.               # identity
.foo            # field access
.foo?           # optional (suppress errors)
.[0]            # array index
.[-1]           # negative index (from end)
.[2:5]          # array slice
.[:-1]          # slice (all but last)
.[]             # iterate all elements
.[]?            # optional iterate
.foo.bar        # chaining
.foo | length   # pipes

# Literals
42, 3.14        # numbers
"hello"         # strings
true, false     # booleans
null            # null

# Comparisons
.x == 5         # equal
.x != "foo"     # not equal
.x < 10         # less than
.x <= 10        # less or equal
.x > 0          # greater than
.x >= 0         # greater or equal

# Boolean operators
.a and .b       # logical and
.a or .b        # logical or
.x > 0 and .x < 10  # compound conditions

# Conditionals
if .x > 0 then "pos" else "neg" end
.name // "default"   # alternative (if null/false)

# Construction
[.a, .b]        # array
{name: .foo}    # object
{(.key): .val}  # dynamic key

Builtins

Builtin	Description
`length`	Length of string, array, or object
`keys`	Object keys or array indices
`values`	Object or array values
`type`	Type name as string
`first`	First element of array
`last`	Last element of array
`reverse`	Reverse array
`sort`	Sort array
`min`	Minimum value in array
`max`	Maximum value in array
`unique`	Remove duplicates from array
`flatten`	Flatten nested arrays
`add`	Sum numbers, concat strings/arrays, merge objects
`empty`	Produce no output
`not`	Boolean negation
`to_entries`	Object to `[{key, value}, ...]`
`from_entries`	`[{key, value}, ...]` to object

Functions

Function	Description
`map(f)`	Apply filter to each array element
`select(f)`	Keep values where `f` is truthy
`sort_by(f)`	Sort array by extracted key
`group_by(f)`	Group array elements by key
`unique_by(f)`	Remove duplicates by key
`min_by(f)`	Element with minimum key
`max_by(f)`	Element with maximum key
`has("key")`	Check if object has key
`split("delim")`	Split string into array
`join("sep")`	Join array into string
`startswith("s")`	Check if string starts with prefix
`endswith("s")`	Check if string ends with suffix
`contains(value)`	Check if value contains another
`with_entries(f)`	Transform object entries

Building

cargo build --release

License

MIT

jarq 0.5.1