https://github.com/brevity1swos/rgx
regex101 for the terminal — real-time matching, 3 engines, capture groups, replace mode, syntax highlighting, plain-English explanations, undo/redo, mouse support. Written in Rust.
https://github.com/brevity1swos/rgx
cli command-line cross-platform developer-tools linux macos pcre2 productivity regex regex-debugger regex-tester rust terminal text-processing tui windows
Last synced: 8 days ago
JSON representation
regex101 for the terminal — real-time matching, 3 engines, capture groups, replace mode, syntax highlighting, plain-English explanations, undo/redo, mouse support. Written in Rust.
- Host: GitHub
- URL: https://github.com/brevity1swos/rgx
- Owner: brevity1swos
- License: apache-2.0
- Created: 2026-02-22T02:55:33.000Z (4 months ago)
- Default Branch: main
- Last Pushed: 2026-05-30T15:53:23.000Z (15 days ago)
- Last Synced: 2026-05-30T17:22:28.499Z (15 days ago)
- Topics: cli, command-line, cross-platform, developer-tools, linux, macos, pcre2, productivity, regex, regex-debugger, regex-tester, rust, terminal, text-processing, tui, windows
- Language: Rust
- Homepage: https://github.com/brevity1swos/rgx
- Size: 28.6 MB
- Stars: 208
- Watchers: 1
- Forks: 3
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- Funding: .github/FUNDING.yml
- License: LICENSE-APACHE
- Roadmap: docs/ROADMAP.md
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README
# rgx
**A regex debugger for the terminal — step-through execution, 3 engines, code generation, and live stream filtering**
[](https://github.com/brevity1swos/rgx/actions/workflows/ci.yml)
[](https://crates.io/crates/rgx-cli)
[](https://crates.io/crates/rgx-cli)
[](LICENSE-MIT)
Test and debug regular expressions without leaving your terminal. Written in Rust.
*Press F1 in the app for a multi-page cheat sheet.*
---
## Who is this for?
rgx is useful if you:
- **Work on remote servers** where opening a browser isn't practical — SSH, containers, air-gapped environments.
- **Want to pipe regex results** into other commands (`echo "log" | rgx -p '\d+' | sort`) — regex101 can't do this.
- **Need engine-specific behavior** — check whether a pattern works in Rust's `regex` crate vs. PCRE2 without guessing.
- **Prefer staying in the terminal** and find the context switch to a browser disruptive.
If you write regex a few times a month and regex101.com works fine for you, it probably still will. rgx is strongest for developers doing regex-heavy work in terminal-centric workflows.
## Install
```bash
cargo install rgx-cli # crates.io
brew install brevity1swos/tap/rgx # Homebrew
yay -S rgx-cli # AUR
curl --proto '=https' --tlsv1.2 -LsSf \
https://github.com/brevity1swos/rgx/releases/latest/download/rgx-installer.sh | sh
```
Prebuilt binaries are also on [GitHub Releases](https://github.com/brevity1swos/rgx/releases/latest).
Build from source / enable PCRE2
```bash
# From source
git clone https://github.com/brevity1swos/rgx.git
cd rgx && cargo install --path .
# With PCRE2 engine (requires libpcre2-dev)
cargo install rgx-cli --features pcre2-engine
```
See [docs/advanced.md](docs/advanced.md#building-with-pcre2) for the PCRE2 security note.
## Quickstart
```bash
rgx # interactive TUI
rgx '\d{3}-\d{3}-\d{4}' # start with a pattern
echo "Call 555-123-4567" | rgx '\d+' # stdin as test string
rgx -p -t "error 404" '\d+' # batch mode (non-interactive)
cat app.jsonl | rgx filter --json '.msg' 'error' # live stream filter on a JSON field
```
Full flag reference, piping recipes, and `rgx filter` + `--json` usage:
**[docs/usage.md](docs/usage.md)**.
## Features
- **Step-through debugger** (Ctrl+D, PCRE2) — backtracking visualization, heatmap mode, dual-cursor trace
- Real-time matching with AST-based syntax highlighting and capture-group colors
- **3 regex engines**: Rust `regex` (default), `fancy-regex` (lookaround / backrefs), PCRE2 (+ recursion / conditionals)
- **Auto engine selection** — upgrades engines automatically when your pattern needs lookahead, backreferences, or recursion
- **Plain-English explanations** for any pattern, generated from the AST
- **Code generation** — Ctrl+G produces ready-to-paste code in 8 languages (Rust, Python, JS, Go, Java, C#, PHP, Ruby)
- **Generate regex from examples** — Ctrl+X opens a [grex](https://crates.io/crates/grex) overlay
- **Live filter mode** — `rgx filter` streams stdin/file through a regex TUI, with `--json` JSONL-field extraction
- **Test suite mode** — `rgx --test file.toml` validates patterns against assertions in CI
- **Non-interactive batch mode** — `-p` with `--count`, `--group`, `--json`, `--color`, grep-like exit codes
- **Benchmark mode** — Ctrl+B compares compile and match time across all engines
- **regex101.com export** — Ctrl+U copies a shareable regex101 URL to clipboard
- **Output pattern mode** — `-P` prints the final pattern after an interactive session (`eval $(rgx -P)`)
- **Vim mode**, **mouse**, **pattern history + undo/redo**, **clipboard copy**, **whitespace visualization**
- **Workspaces** — save/load regex state to a TOML file (`-w`) — track in git
- **Editor integrations** — VS Code, Neovim, Zed, tmux
- **Shell completions** — `--completions bash|zsh|fish`
- **Cross-platform** — Linux, macOS, Windows
## Documentation
- **[Usage](docs/usage.md)** — interactive / batch / filter modes, all flags, piping recipes
- **[Keyboard shortcuts](docs/shortcuts.md)** — main TUI, vim mode, filter mode
- **[Editor integrations](docs/integrations.md)** — VS Code, Neovim, Zed, tmux
- **[Advanced](docs/advanced.md)** — test suite mode, config file, engines deep-dive, comparison matrix
## Engines at a glance
| Engine | Features | Dependencies |
|--------|----------|--------------|
| **Rust `regex`** (default) | Fast, linear time, Unicode | Pure Rust |
| **fancy-regex** | + lookaround, backreferences | Pure Rust |
| **PCRE2** | + possessive quantifiers, recursion, conditionals | `libpcre2` |
Full matrix and comparison against other tools: [docs/advanced.md](docs/advanced.md#comparison-vs-terminal-alternatives).
## Contributing
See [CONTRIBUTING.md](CONTRIBUTING.md).
## License
Licensed under either of
- Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE))
- MIT License ([LICENSE-MIT](LICENSE-MIT))
at your option.