dan

A fast, friendly, lightweight yet highly capable terminal text editor written in Rust. Dan is modeless, requires no configuration to get started, and stays fast even over slow or unstable SSH connections and while working with very large files.

Quick install

Install or update Rust:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Clone, build, and install Dan:

git clone https://github.com/dfallman/dan.git
cd dan
cargo install --path .

For more installation options, see Installation.

Features

Dan uses familiar shortcuts out of the box — Ctrl-C/V to copy/paste, Ctrl-S to save, Ctrl-Z/Y to undo/redo, Ctrl-Q to quit. Press Ctrl-H to toggle the built-in help bar at any time.

• Command palette (Ctrl-P): A searchable overlay covering every editor action, all open buffers, and project files. Switch buffers, open files, or trigger any command without leaving the keyboard.

Dan's command palette

• Multiple buffers: Dan supports multiple open buffers simultaneously, managed through the command palette.

• Rendering: Differential rendering — only changed cells are written to the terminal. A syntax snapshot cache (taken every 200 lines) means scrolling deep into long files stays smooth, including over slow SSH links.

• Text buffer: Rope-backed, so inserts and deletes are O(log N) and memory use scales with edits rather than file size. Dan handles very large files without loading them into a flat string.

• Syntax highlighting: Powered by syntect, with broad language support. Dan queries your terminal's background color at startup and picks a sensible default theme. Override the theme via config, or toggle syntax highlighting on/off with Ctrl-T.

• Auto-formatter (Ctrl-L): Pipes the buffer through an external formatter (Prettier, Rustfmt, or Ruff) in a background thread. The result is applied only if the buffer hasn't been edited during formatting. See Formatter.

• Search & replace: Ctrl-F to search; press Ctrl-R while searching to promote to find-and-replace.

• Atomic saves: Saves go through a sibling temp file → fsync → rename. A crash or full disk mid-write leaves the file in its prior state rather than truncated. Original permissions and symlink targets are preserved.

• Crash recovery: Every 5 seconds, Dan writes the buffer to a hidden .swp file using the same safe write pattern. If the terminal crashes or SSH drops, reopening the file prompts for recovery.

• Unicode & CJK support: Correct visual alignment for double-width characters and emojis.

• Native OS clipboard support: Cross-platform via arboard, with an in-memory fallback when no display server is available (e.g., headless SSH).

• Auto-pairs: Closing brackets and quotes auto-insert on typing; typing a bracket around an active selection wraps it.

• File encoding detection: Detects legacy encodings (Shift-JIS, Windows-1252, etc.) on open, works in UTF-8, and round-trips back to the original encoding on save.

• Content safety: Terminal escape sequences embedded in file content are sanitized at render time, so opening a hostile file can't write over the editor chrome or exfiltrate clipboard state.

• Layered config: Internal defaults → ~/.config/dan/config.toml → .editorconfig in the project tree. See Configuration.

Keyboard shortcuts

Basic operation

Key	Action
↑ ↓ ← →	Move cursor
Ctrl + S	Save
Ctrl + A	Save As
Ctrl + Q	Quit (prompts if there are unsaved changes)
Ctrl + H	Toggle help bar
Ctrl + P	Command palette (actions, buffers, project files)

Text editing

Key	Action
Ctrl + C / X / V	Copy / Cut / Paste
Ctrl + Z / Y	Undo / Redo
Ctrl + D	Duplicate line or selection
Ctrl + K	Delete line or selection
Ctrl + E (or Ctrl + /)	Toggle comment (syntax-aware)
Ctrl + T	Toggle syntax highlighting
Ctrl + W	Toggle word wrap
Ctrl + R	Toggle whitespace markers
Ctrl + L	Format document
Alt + ↑ / ↓	Move line up / down
Tab / Shift + Tab	Indent / Dedent

Selection

Key	Action
Ctrl + \	Select all
Shift + Arrows	Extend selection
Ctrl/Alt + Shift + ← / →	Extend selection by word

Navigation

Key	Action
Ctrl + ↑ / ↓	Scroll without moving cursor
Ctrl + Shift + ↑ / ↓	Fast scroll
Ctrl / Alt + ← / →	Jump by word
Ctrl + Home / End	Jump to start / end of file
Ctrl + G	Go to line

Search & replace

Key	Action
Ctrl + F	Search
Ctrl + R (while searching)	Promote to find-and-replace

Note for macOS users: Terminal emulators use escape sequences dating back to the late 70s and some at the time highly influential video display terminals such as VT100. Long story short, this means some "modern" key combinations available in GUI editors can't be distinguished in a terminal. Most notably, Dan (and other terminal apps) uses Ctrl where a Mac user might expect ⌘. Many terminal emulators (including iTerm2) let you remap ⌘ to Ctrl if you prefer, although it can create side-issues. Additionally, the built-in Terminal.app is not recommended: a third-party emulator such as iTerm2, Kitty, Ghostty, or WezTerm will give better results.

Installation

Dan requires Rust v1.94 or later. We recommend installing via rustup rather than your system package manager, which often provides an older version:

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

To install on Windows, follow these instructions.

macOS & Linux

git clone https://github.com/dfallman/dan.git
cd dan
cargo build --release
cp target/release/dan /usr/local/bin/
# or
cargo install --path .

Windows

Note: If you're running Dan inside WSL, follow the Linux instructions above instead.

git clone https://github.com/dfallman/dan.git
cd dan
cargo build --release
Copy-Item target\release\dan.exe ~/.cargo/bin/

Configuration

Dan works without any configuration file. To customize it, create ~/.config/dan/config.toml (on Windows: C:\Users\<username>\AppData\Roaming\dan\config.toml) and add the options you want to change. Full defaults are shown below for reference.

dan ~/.config/dan/config.toml

# Display
wrap_lines = true           # Wrap long lines (default: true)
tab_width = 4               # Visual tab width (default: 4)
expand_tab = false          # Insert spaces instead of tabs (default: false)
line_numbers = true         # Show line numbers (default: true)
highlight_active = true     # Highlight the current line (default: true)
scroll_off = 5              # Lines to keep visible above/below cursor (default: 5)
fast_scroll_steps = 10      # Lines jumped per fast-scroll keypress (default: 10)
show_full_path = false      # Show full file path in toolbar (default: false)

# Editing
auto_indent = true          # Match indentation of the previous line (default: true)
auto_close = true           # Auto-insert closing brackets and quotes (default: true)
syntax_highlight = true     # Enable syntax highlighting (default: true)

# Interface
show_help = true            # Show shortcut bar at the bottom (default: true)
show_encoding = true        # Show file encoding in status bar (default: true)
show_lang = true            # Show detected language in status bar (default: true)

# Theme
theme = "default"           # Syntax highlight theme; "default" auto-detects terminal background
comments_are_italics = true # Render comments in italics (default: true)

Project-aware settings

Dan automatically picks up .editorconfig files in the project tree. Tab width, line endings, and trailing-whitespace rules defined there take precedence over your global config, so Dan adapts to each project's style without manual adjustment.

Themes

When theme = "default", Dan queries your terminal's background color at startup and picks OneHalfDark for dark terminals or OneHalfLight for light terminals. Toggle syntax highlighting on/off at any time with Ctrl-T.

To use a specific theme, set it in your config:

theme = "DarkNeon"

Note: macOS's built-in Terminal.app does not render ANSI colors correctly. A third-party terminal emulator is recommended for best results.

Available themes:

Theme	Style
OneHalfDark	Clean modern dark (default for dark terminals)
OneHalfLight	Clean modern light (default for light terminals)
Dracula	High-contrast dark, purple/pink accents
Nord	Arctic-inspired dark
Monokai Extended	Classic Monokai, updated
Monokai Extended Bright	Higher-contrast Monokai variant
Monokai Extended Light	Light-background Monokai
Monokai Extended Origin	Original unaltered Monokai
Visual Studio Dark+	VS Code default dark
GitHub	Light, mimics GitHub's code view
Solarized (dark) / Solarized (light)	Classic low-contrast Solarized
gruvbox-dark / gruvbox-light	Warm, earthy retro tones
Coldark-Cold	Blue-tinted light
Coldark-Dark	Cool-blue dark
DarkNeon	Vibrant dark with neon accents
Sublime Snazzy	Bright, elegant dark
TwoDark	Atom One Dark with slightly better contrast
1337	High-contrast dark
zenburn	Low-contrast, easy on the eyes
base16 / base16-256	Standard base16 (256-color variant available)
ansi	Uses your terminal's 16 built-in ANSI colors

Formatter

Ctrl-L pipes the current buffer to an external formatter in a background thread. The formatted result is applied only if the buffer hasn't changed during formatting — keystrokes made while a slow format runs are not discarded. Dan detects the right formatter based on file type:

• Rust: rustfmt — rustup component add rustfmt
• Python: ruff — pip install ruff
• JS / TS / JSON / CSS / HTML: prettier — npm i -g prettier

Formatter output and errors are shown in the status bar.

Note on AI use

I've been writing code for over 30 years. Lately, LLM agent-enhanced coding practices have rekindled my sense of awe at what's possible. This project has been built using a range of tools, including Anthropic's Claude Code (with Opus 4.7).

Unlike some who dismiss anything touched by a coding agent as "slop," I don't see it that way. To me, these tools are a way to move much faster, explore many more ideas, and test those ideas and implementations more rigorously than I ever could on my own.

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License: GNU General Public License v3.0 (GPLv3)