rgx - Terminal Regex Debugger
Test, debug, and visualize regex patterns without leaving VS Code. rgx runs in the integrated terminal with real-time matching, capture group highlighting, and plain-English explanations.
Features
- Step-through debugger — Ctrl+D visualizes regex engine state at each step, with backtracking markers and a heatmap mode (PCRE2)
- Real-time matching — see matches update as you type
- Capture group highlighting — colored groups with numbered labels, alternating match colors
- Plain-English explanations — understand any pattern at a glance
- Live filter mode —
rgx filter streams stdin/file through a regex TUI; supports --json JSONL-field extraction, --count, --line-number, --invert, and grep-like exit codes
- Quick Reference side panel — F3 toggles a syntax cheat sheet on the right edge of the screen
- Multi-engine support — switch between Rust regex, fancy-regex (lookaround/backrefs), and PCRE2
- Auto engine selection — automatically upgrades the engine when your pattern needs lookahead, backreferences, or recursion
- Code generation — Ctrl+G generates ready-to-use code in Rust, Python, JavaScript, Go, Java, C#, PHP, or Ruby
- Benchmark across engines — Ctrl+B measures compile and match time for the same pattern on all available engines
- Regex from examples — Ctrl+X opens a grex overlay that infers a pattern from sample strings
- Replace mode — test substitutions with live preview
- Test suite mode — validate regex against assertions with
rgx --test file.toml
- Workspaces — Ctrl+S saves pattern + test string + flags to a TOML file you can track in git
- Pattern history + undo/redo — browse and recall previous patterns; Ctrl+Z / Ctrl+Shift+Z
- Recipe library — built-in patterns for common tasks (email, URL, IP, etc.)
- Vim mode — optional vim keybindings
- regex101 export — Ctrl+U generates a shareable regex101.com URL
Requirements
rgx must be installed and available on your PATH.
Install via Cargo:
cargo install rgx-cli
Install via Homebrew:
brew install brevity1swos/tap/rgx
Install via AUR (Arch Linux):
yay -S rgx-cli
Commands
| Command |
Description |
rgx: Open |
Launch rgx in the integrated terminal |
rgx: Open with Selection |
Launch rgx with the current selection as test text |
rgx: Open with Pattern |
Launch rgx with the current selection as the regex pattern |
rgx: Filter Current File with Pattern |
Run rgx filter against the current file with the selection as pattern |
Access commands via the Command Palette (Ctrl+Shift+P / Cmd+Shift+P) and search for rgx.
Key Shortcuts (inside rgx)
| Key |
Action |
Ctrl+D |
Step-through regex debugger (PCRE2) |
Ctrl+G |
Generate code for the current pattern (8 languages) |
Ctrl+B |
Benchmark pattern across all engines |
Ctrl+X |
Generate regex from examples (grex overlay) |
Ctrl+R |
Open regex recipe library |
Ctrl+U |
Copy regex101.com URL to clipboard |
Ctrl+E |
Cycle regex engine |
Ctrl+Y |
Copy pattern (regex panel) or selected match (matches panel) |
Ctrl+W |
Toggle whitespace visualization |
Ctrl+S |
Save workspace |
Ctrl+O |
Output results to stdout and quit |
Ctrl+Z / Ctrl+Shift+Z |
Undo / redo |
F1 |
Show help (Left/Right page, Up/Down scroll) |
F3 |
Toggle Quick Reference side panel |
PgUp / PgDn |
Scroll Quick Reference side panel |
Settings
| Setting |
Type |
Default |
Description |
rgx.path |
string |
"rgx" |
Path to the rgx binary |
rgx.defaultEngine |
string |
(none) |
Default regex engine: rust, fancy, or pcre2 |
Usage
- Open a file in VS Code.
- Optionally select text (a test string or a regex pattern).
- Open the Command Palette and run one of the
rgx: commands.
- rgx launches in the integrated terminal with your selection pre-loaded.
Links
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