Initial working shell: bash-for-windows

- Cross-compiled Go-based shell for Windows (PE32+ executable)
- Builtins: cd, pwd, echo, exit, export, source, alias, type
- Coreutils: ls, cat, grep, sort, wc, head, find, cp, mv, rm, mkdir, touch, clear
- Command chaining: &&, ||, ;
- Pipes between builtins and external commands
- Variable expansion (, ) and assignment (NAME=VALUE)
- Tokenizer with single/double quote handling
- Linux and Windows (x86_64) builds via build.sh

README.md

@@ -1,3 +1,62 @@
 # bash-for-windows
 
-Fully functional bash for windows
+A fully functional bash shell for Windows, written in Go. Run bash commands and scripts natively on Windows without WSL, Cygwin, or MSYS2.
+
+## Features
+
+- **Interactive shell** with prompt (`bash$`)
+- **Built-in commands**: cd, pwd, echo, exit, export, source, alias, type
+- **Built-in coreutils**: ls, cat, grep, sort, wc, head, find, cp, mv, rm, mkdir, touch, clear
+- **Command chaining**: `&&`, `||`, `;`
+- **Pipes**: `|` between commands
+- **Variable expansion**: `$NAME`, `${NAME}`
+- **Variable assignment**: `NAME=VALUE command`
+- **Single & double quotes**: `'literal'`, `"$variable"`
+- **Script execution**: `bash-windows script.sh` or `-c 'commands'`
+- **No dependencies** — single `.exe` file, runs on any Windows x86-64
+
+## Usage
+
+```
+bash-windows            # Interactive mode
+bash-windows -c 'echo hello'
+bash-windows script.sh
+```
+
+### Examples
+
+```
+bash$ echo "Hello from bash-for-windows!"
+bash$ ls -la
+bash$ cd /tmp && pwd
+bash$ cat file.txt | grep pattern | wc -l
+bash$ name="Luffy" && echo $name
+bash$ mkdir -p project/src && touch project/src/main.go
+```
+
+## Building
+
+Requires Go 1.21+.
+
+```bash
+# Linux
+./build.sh
+
+# Manual
+go build -o build/bash-windows .
+
+# Windows cross-compile
+GOOS=windows GOARCH=amd64 CGO_ENABLED=0 go build -o build/bash-windows.exe .
+```
+
+## Project Structure
+
+```
+cmd/bash/        - Shell entry point
+internal/shell/  - Shell engine (parser, executor, builtins, coreutils)
+build/           - Compiled binaries
+```
+
+## License
+
+MIT