🐚 0-shell

0-shell is a minimalist, Unix-like shell implemented in Rust, built entirely from scratch to support basic Unix commands without relying on external binaries or traditional shell interpreters like bash or sh.

Inspired by BusyBox, this shell is tailored for embedded systems, learning environments, and low-resource deployments, with full control over command behavior and system-level interaction.

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✨ Features

✅ Built-in command execution
✅ No use of /bin/* or other external binaries
✅ Handles user input, errors, and edge cases robustly
✅ Graceful Ctrl+D (EOF) exit
✅ Minimal memory usage thanks to Rust safety

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🛠️ Build & Run

Prerequisites

• Rust (1.70+ recommended)
• cargo build tool (comes with Rust)

🧾 Supported Commands

These commands are implemented manually, without shelling out to system tools.

📂 Navigation & Filesystem

Command	Description
cd [dir]	Change current directory (cd for home, cd - for previous)
pwd	Print working directory
mkdir name	Create a new directory
rm [-r] target	Delete a file or recursively delete a directory
ls [-l -a -F]	List directory contents (long, all files, classify)

📝 File Manipulation

Command	Description
cat [file ...]	Print file(s) to stdout or read from stdin (-)
cp src dst	Copy a file or multiple files to a destination
mv src dst	Move/rename file(s) or move into a directory

📣 Output

Command	Description
echo [text]	Print to stdout; supports ~ expansion and quoted strings

⛔ Exit

Command	Description
exit	Exit the shell

🔍 Example Usage

$ ./0-shell
$ cd dev
$ pwd
/dev
$ ls -l
total 0
crw-------  1 root   root     10,    58 Feb  5 09:21 acpi_thermal_rel
crw-r--r--  1 root   root     10,   235 Feb  5 09:21 autofs
drwxr-xr-x  2 root   root           540 Feb  5 09:21 block
...
$ something
Command 'something' not found
$ echo "Hello There"
Hello There
$ exit
$