# DOS-Like Shell (Zig)

A small DOS-inspired shell implemented in Zig. It aims to reproduce the feel of classic MS-DOS utilities and behaviors, including 8.3 filename formatting, backslash paths, simple prompts, and a subset of built-in commands.

This project is educational and intentionally simplified; it is not a full DOS emulator or a drop-in replacement for CMD.

## Features

- DOS-style prompt with basic variables:
  - `$p` current path (formatted in DOS style)
  - `$g` greater-than character (`>`)
- Path handling:
  - Converts `/` to `\` and uppercases drive letters and names
  - Formats individual path segments to 8.3-style names where applicable
  - Defaults to `C:` when no drive is present
- Built-in commands (subset):
  - `ECHO` (plain and text)
  - `CLS`
  - `EXIT`
  - `VER`
  - `DATE` and `TIME` (simplified calculations/formatting)
  - `DIR` (lists files/directories with simplified date/time and sizes)
  - `TYPE` (prints file contents with basic character handling)
  - `SORT` (reads from redirected input and prints sorted lines)
  - `CD`/`CHDIR` (change directory; basic cases like `..` and root)
  - `COPY` (file copy; also supports `COPY CON destination` for interactive input until Ctrl+Z)
  - `DEL`/`ERASE` (file removal; no wildcards yet)
  - `MKDIR`/`MD` (make directory)
- Redirection:
  - Input: `< file`
  - Output overwrite: `> file`
  - Output append: `>> file`
- External command execution:
  - Executes programs in your environment when not matched by a built-in

## Limitations

- Simplified date/time and calendar calculations
- No full wildcard support (e.g., in `DEL`)
- Device names (`CON`, `PRN`, `LPTx`) are recognized in limited contexts
- Not a complete DOS environment; behavior is “DOS-like” rather than exact

## Build

Requirements:
- Zig (recent version)

Build:

```
zig build
```

This produces an executable in `zig-out/bin`.

## Run

Start the shell:

```
zig-out/bin/dose
```

You’ll see a DOS-like prompt. Example interactions:

```
C:\> VER
DOSE Version 6.22
C:\> DIR
... directory listing ...
C:\> COPY CON hello.txt
Hello world! 
^Z
 1 File(s) copied
C:\> TYPE hello.txt
Hello world!
```

Redirection:

```
C:\> DIR > dir.txt
C:\> TYPE dir.txt
```

Change directory:

```
C:\> CD ..
C:\> DIR
```

## Development Notes

- The shell uses a simple parser and a set of built-in command handlers.
- Paths shown to the user are normalized to DOS conventions (uppercase, backslashes, and 8.3-style segments).
- External commands are executed via the host OS process APIs; errors are reported in a DOS-like manner.

## Roadmap

- Wildcards for file operations
- More built-in commands and switches
- Improved date/time correctness
- Better device/file semantics
- Enhanced error messages and testing

## License

GNU AGPLv3.