Open-Source Observability · rcoh

angle-grinder

Angle-grinder is a command-line tool for real-time log analysis and aggregation written in Rust. It enables parsing, filtering, and computing analytics (counts, sums, percentiles, grouping) on log streams without external infrastructure.

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Source: GitHub — github.com/rcoh/angle-grinder

3.7k

GitHub stars

Forks

Rust

Primary language

MIT

License (OSI-approved)

Key facts

Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.

Field	Value
Repository	rcoh/angle-grinder
Owner	rcoh
Primary language	Rust
License	MIT — OSI-approved
Stars	3.7k
Forks	74
Open issues	28
Latest release	v0.19.6 (2025-03-29)
Last updated	2026-02-05
Source	https://github.com/rcoh/angle-grinder

What angle-grinder is

A Rust CLI processing logs via a functional pipeline syntax supporting parsers (JSON, logfmt, regex, split), filters, and aggregators. Handles >1M rows/sec with live terminal UI updates. Supports aliases for templated queries.

Quickstart

Get the angle-grinder source

Clone the repository and explore it locally.

terminalbash

1git clone https://github.com/rcoh/angle-grinder.git2cd angle-grinder3# follow the project's README for install & configuration

Need it deployed, integrated, or customized instead? DEV.co ships production installs.

Best use cases

Ad-hoc log analysis in production

Quickly parse and aggregate logs from files or streams when centralized logging is unavailable or slow to query.

Local development log debugging

Developers can slice, filter, and count log entries on their machine without deploying to a logging platform.

Performance metrics extraction

Extract latencies, status codes, or error rates from application logs with percentile and statistical operators.

Implementation considerations

Binary is pre-built for Linux, macOS, and FreeBSD; Windows requires compilation from source.
No dependencies on external services; runs locally with minimal overhead.
Query syntax (filters, parsers, aggregators) must be learned; templates via aliases can reduce repetition.
Performance is single-threaded per invocation; scales well for typical log volumes but not a replacement for distributed analytics systems.
Output is live-updating in the terminal; integration into CI/CD or batch pipelines requires parsing text output.

When to avoid it — and what to weigh

Require persistent log storage and search — Angle-grinder is ephemeral; it does not store logs or provide long-term indexing like Splunk or Kibana.
Need multi-source log correlation — Designed for single-stream or file input; not built for correlating logs across distributed services.
Require advanced visualization and alerting — Limited to terminal output; lacks dashboards, alerts, and retention policies of enterprise log platforms.
Team unfamiliar with CLI and functional query syntax — Requires learning a custom query language and comfort with command-line tools; not a graphical interface.

License & commercial use

MIT License permits unrestricted use, modification, and distribution in commercial and private contexts, with no warranty.

MIT is a permissive OSI-approved license. Commercial use, modification, and redistribution are allowed. Redistribution requires attribution and preservation of the license notice.

DEV.co evaluation signals

Editorial assessment — not user reviews. Directional, with an explicit confidence level.

Signal	Assessment
Maintenance	Active
Documentation	Adequate
License clarity	Clear
Deployment complexity	Low
DEV.co fit	Good
Assessment confidence	High

Security considerations

Runs locally on user's machine with access to file system and stdin. No network communication or data exfiltration observed in description. Regex parsing uses Rust regex engine; consider input validation if processing untrusted log sources. No security audit or CVE history provided.

Alternatives to consider

jq + awk/grep

Unix standbys for filtering and transforming JSON/text; more portable, no installation required, but less ergonomic for complex multi-stage pipelines and aggregation.

Splunk or Datadog

Enterprise solutions with persistent storage, distributed querying, dashboards, and alerting; much higher cost and operational overhead.

LogQL (Loki)

Open-source log aggregation and query language; requires infrastructure setup but enables distributed log collection and longer retention.

Software development agency

Build on angle-grinder with DEV.co software developers

Angle-grinder gives your team a lightweight CLI for ad-hoc log queries and performance metrics. Ideal for DevOps and backend teams without centralized logging.

Talk to DEV.co

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angle-grinder FAQ

Can I use angle-grinder on Windows?

Pre-built binaries for Windows are not listed in the README. Compilation from source via Rust is possible but not officially documented.

Does angle-grinder persist or store logs?

No. It is designed for ephemeral analysis of live streams or files. Once the process ends, results are lost unless redirected to a file.

What is the maximum throughput?

README states >1M rows/sec for typical pipelines and up to 5M rows/sec for simple operations. Performance depends on parsing complexity and query structure.

How do I integrate with CI/CD or scripts?

Angle-grinder outputs text to the terminal. Parsing its output programmatically is possible but not built-in; consider exporting to JSON or CSV for downstream processing.

Custom software development services

DEV.co helps companies turn open-source tools like angle-grinder into production software. Our software development services cover the full lifecycle — architecture, web development, integration, and maintenance — delivered by software developers and web developers who ship. Engage our software development agency to implement or customize it for your open-source observability stack.

Need fast, local log analysis?

Angle-grinder gives your team a lightweight CLI for ad-hoc log queries and performance metrics. Ideal for DevOps and backend teams without centralized logging.

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