How do I extract a nested JSON value with jql?

Use key selectors with double quotes, chaining them for depth, e.g., jql '"parent""child"' input.json. For recursive access, employ the flatten operator .. to simplify nested structures.

jql vs jq: which is faster for simple queries?

jql is generally faster for basic operations due to its Rust implementation, as shown in benchmarks, but jq offers more features for complex tasks. Choose jql if speed and simplicity are key.

Can jql process streaming JSON logs?

Yes, use the --stream flag to handle JSON data streamed line by line, such as from Docker logs or real-time outputs, making it suitable for log analysis pipelines.

What's the best way to install jql on Windows?

Download the pre-compiled binary from GitHub releases or use Cargo if Rust is installed, as Windows package managers aren't listed, but manual installation is straightforward.

Does jql support regular expressions for filtering?

No, jql does not support regex in queries; it relies on exact key matching and simple selectors, unlike jq which includes regex capabilities for flexible filtering.

How to flatten a deeply nested JSON object with jql?

Apply the flatten operator .., e.g., jql '..' input.json, which recursively converts nested objects into flat key-value pairs with dot notation for keys.

Is jql good for validating JSON files?

Yes, use the --validate flag to check JSON integrity and return exit codes based on validity, making it useful for automated testing and data quality checks.

Open-Awesome

jql

Apache-2.0Rustjql-v8.1.2

A fast, lightweight JSON Query Language CLI tool built with Rust for querying and transforming JSON data.

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1.7k stars32 forks0 contributors

What is jql?

jql is a JSON Query Language CLI tool built with Rust that allows developers to query, filter, and transform JSON data using a simple token-based syntax. It takes JSON as input, processes it according to the query, and outputs JSON, making it useful for data extraction and manipulation in scripts and pipelines.

Target Audience

Developers and system administrators who work with JSON data in command-line environments and need a fast, lightweight tool for querying and transforming JSON structures.

Value Proposition

Developers choose jql for its speed and simplicity—it's built with Rust for performance, has a minimalistic design, and provides a straightforward query syntax without the complexity of alternatives like jq.

Overview

A JSON Query Language CLI tool

Use Cases

Best For

Extracting specific fields from large JSON responses in shell scripts
Filtering and transforming JSON logs or API outputs in pipelines
Quickly querying nested JSON structures without writing custom parsers
Flattening deeply nested JSON objects into key-value pairs
Processing JSON arrays in parallel with pipe operators
Validating JSON data integrity in automated workflows

Not Ideal For

Developers needing complex JSON transformations with conditional logic or regex support
Teams with existing jq scripts or dependencies requiring compatibility
Use cases involving non-JSON data formats or multi-format pipelines
Projects demanding extensive community plugins or third-party integrations

Pros & Cons

Pros

Rust-Powered Speed

Built with Rust for high-performance JSON processing, with benchmarks showing competitive speeds against tools like jq, as noted in the PERFORMANCE.md file.

Minimalist and Portable

Lightweight design with small binary size and minimal dependencies, making installation easy via various package managers like Homebrew and Cargo.

Intuitive Token Syntax

Simple token-based queries for selecting array elements, object keys, and ranges, reducing the learning curve compared to more complex DSLs.

Advanced Flattening Operator

Recursively flattens nested arrays and objects into key-value pairs or simplified lists, useful for data normalization in scripts.

Parallel Processing Support

Pipe-in and pipe-out operators enable parallel handling of array elements, enhancing efficiency for bulk JSON data manipulation.

Cons

Limited Jq Compatibility

Explicitly states no plan to align with jq, making migration from jq scripts difficult and limiting feature parity for advanced users.

Syntax Shell Escaping Hassles

Requires double-quoted keys and careful shell escaping in queries, which can be error-prone and cumbersome in complex scripting environments.

Narrower Feature Scope

Lacks advanced transformations found in jq, such as custom functions, regex matching, and complex string manipulation, as admitted in the non-goal section.

Immature Ecosystem

Smaller community and fewer resources compared to established alternatives, which may affect long-term support and troubleshooting.

Open Source Alternative To

jql is an open-source alternative to the following products:

jq is a lightweight and flexible command-line JSON processor for parsing, filtering, and transforming JSON data.

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