> The Jitzu shell includes a custom readline implementation with tab completion, history predictions, reverse search, text selection, and full line-editing support.

# Completion & Editing

The Jitzu shell includes a custom readline implementation with tab completion, history
predictions, reverse search, text selection, and full line-editing support.

## Tab Completion

Press **Tab** to trigger context-aware completions. The shell completes:

- **File paths** — files and directories in the current directory, with tilde (`~`) and label expansion
- **Built-in commands** — all 60+ shell builtins
- **Executables on PATH** — programs available in your system PATH
- **Jitzu identifiers** — variables, functions, and types from the current session
- **Label paths** — type a label prefix (e.g. `git:`) and Tab completes paths within the labeled directory

### Completion Workflow

If there's a single match, it's applied immediately. If there are multiple matches,
a dropdown appears:

- **Up/Down** — navigate the dropdown
- **Tab** — accept the highlighted completion
- **Escape** — dismiss

```shell
> gre⇥         → grep
> src/Pa⇥      → src/Parser.cs
> git:proj⇥    → git:projects/
```

## History Predictions

As you type, the shell shows matching entries from your command history in a dropdown.
Ghost text does not appear until you select an entry.

- **Down Arrow** — enter the history dropdown (ghost text appears for the selected entry)
- **Tab** — accept the selected prediction (or open completions if no entry is selected)
- **Right Arrow** — accept the ghost text
- **Delete** — remove the selected entry from history
- **Escape** — dismiss predictions

## Reverse History Search

Press **Ctrl+R** to enter reverse search mode. Type a substring to search
backward through history. Press **Ctrl+R** again to cycle to the next match.

```shell
(reverse-search): build
→ dotnet build --configuration Release
```

Press **Enter** to execute the match, **Escape** to cancel, or any
other key to exit search mode and edit the matched line.

## History Navigation

When no dropdown is visible, the Up and Down arrow keys navigate through your full command history.
History is persisted to disk across sessions.

- **Up Arrow** — previous command in history
- **Down Arrow** — next command in history
- `history` — display full command history with line numbers

Duplicate commands are deduplicated — only the most recent occurrence is kept.

## Line Editing

### Cursor Movement

<table>
  <thead>
    <tr>
      <th>Shortcut</th>
      <th>Action</th>
    </tr>
  </thead>
  <tbody>
    <tr><td><code>Left / Right</code></td><td>Move cursor one character</td></tr>
    <tr><td><code>Ctrl+Left / Ctrl+Right</code></td><td>Jump by word</td></tr>
    <tr><td><code>Home / Ctrl+A</code></td><td>Move to beginning of line</td></tr>
    <tr><td><code>End</code></td><td>Move to end of line</td></tr>
  </tbody>
</table>

### Editing

<table>
  <thead>
    <tr>
      <th>Shortcut</th>
      <th>Action</th>
    </tr>
  </thead>
  <tbody>
    <tr><td><code>Backspace</code></td><td>Delete character before cursor</td></tr>
    <tr><td><code>Ctrl+Backspace</code></td><td>Delete word before cursor</td></tr>
    <tr><td><code>Delete</code></td><td>Delete character after cursor</td></tr>
  </tbody>
</table>

### Text Selection

<table>
  <thead>
    <tr>
      <th>Shortcut</th>
      <th>Action</th>
    </tr>
  </thead>
  <tbody>
    <tr><td><code>Shift+Left / Shift+Right</code></td><td>Extend selection by character</td></tr>
    <tr><td><code>Shift+Home / Shift+End</code></td><td>Select to beginning/end of line</td></tr>
    <tr><td><code>Ctrl+C</code> (with selection)</td><td>Copy selection to clipboard</td></tr>
  </tbody>
</table>

Typing or pasting while text is selected replaces the selected region.

## Other Shortcuts

<table>
  <thead>
    <tr>
      <th>Shortcut</th>
      <th>Action</th>
    </tr>
  </thead>
  <tbody>
    <tr><td><code>Ctrl+C</code> (no selection)</td><td>Cancel current line</td></tr>
    <tr><td><code>Ctrl+R</code></td><td>Reverse history search</td></tr>
    <tr><td><code>Escape</code></td><td>Dismiss predictions/completions</td></tr>
  </tbody>
</table>

## Syntax Highlighting

The shell prompt applies live syntax coloring as you type, highlighting commands, keywords,
strings, flags, pipe operators, and boolean values. Colors are configurable via the [theme system](/docs/shell/customization).