A lightweight, standalone Unix shell implementation written in Rust for embedded Linux environments. This shell handles basic navigation, file manipulation, and essential shell behaviors without relying on existing shell utilities.

• Overview
• Learning Objectives
• Features
• Built-in Commands
• Project Structure
• Installation
• Usage
• Technical Implementation
• Bonus Features
• Example Session

This project implements a minimalist Unix shell that:

• Displays a prompt ($ ) and waits for user input
• Parses and executes user commands
• Returns to the prompt only after command execution completes
• Handles Ctrl+D (EOF) gracefully to exit the shell
• Prints Command '<name>' not found for unrecognized commands

• Work with file and directory operations
• Manage user input and output within a shell loop
• Implement robust error handling
• Gain experience in Unix process and system call APIs

• Command Parsing: Supports single and double quoting, escape sequences
• Environment Variables: Expansion of $VAR and ${VAR} syntax
• Home Directory Expansion: ~ expands to $HOME
• Quote Continuation: Multi-line input for unclosed quotes with dequote> prompt
• ANSI Escape Handling: Cleans cursor movement sequences from input

• No external binaries or system calls that spawn them
• Basic command syntax only (no piping |, redirection >, or globbing *)
• Shell behavior aligns with Unix conventions

0-shell/
├── Cargo.toml              # Rust package manifest
├── README.md               # This file
└── src/
    ├── main.rs             # Main shell loop and command dispatcher
    ├── parse.rs            # Input parsing, tokenization, variable expansion
    └── commands/
        ├── mod.rs          # Module declarations
        ├── cat.rs          # cat command implementation
        ├── cd.rs           # cd command implementation
        ├── clear.rs        # clear command implementation
        ├── cp.rs           # cp command implementation
        ├── echo.rs         # echo command implementation
        ├── ls.rs           # ls command implementation (with -l, -a, -F)
        ├── mkdir.rs        # mkdir command implementation
        ├── mv.rs           # mv command implementation
        ├── pwd.rs          # pwd command implementation
        └── rm.rs           # rm command implementation (with -r)

• Rust toolchain (rustc, cargo) - Install from rustup.rs

# Clone the repository
git clone https://github.com/AyyoubMh48/0-shell.git
cd 0-shell

# Build the project
cargo build --release

# The binary will be at target/release/kinda_shell

# Run the shell
cargo run

# Or run the compiled binary directly
./target/release/kinda_shell

• Cmd struct: Holds parsed command name and arguments
• clean_input(): Removes ANSI cursor movement sequences
• split(): Tokenizes input with:
  • Single/double quote handling
  • Environment variable expansion ($VAR, ${VAR})
  • Home directory expansion (~)
  • Unclosed quote detection (returns error for continuation)

• Displays $ prompt
• Reads user input line by line
• Handles EOF (Ctrl+D) for graceful exit
• Supports quote continuation with dequote> prompt
• Dispatches commands to appropriate handlers

Each command is implemented as a separate module with its own function:

• echo: Full escape sequence support including hex (\xNN)
• cd: Changes directory, defaults to $HOME if no argument
• ls: Full -l format with permissions, links, owner, group, size, time, and file classification (-F)
• pwd: Prints current working directory
• cat: Reads files or stdin
• cp: Copies files (no recursive directory copy)
• rm: Removes files, -r for recursive directory removal
• mv: Moves/renames files and directories
• mkdir: Creates directories
• clear: Clears terminal using ANSI escape codes

• ✅ Environment variable support ($HOME, $PATH, etc.)
• ✅ Quote continuation for multi-line input
• ✅ Extended ls output with file classification (-F)
• ✅ Clear command for terminal management

• ⬜ Handle Ctrl+C (SIGINT) without crashing
• ⬜ Auto-completion
• ⬜ Command history
• ⬜ Prompt with current directory (e.g., ~/projects/0-shell $)
• ⬜ Colorized output
• ⬜ Command chaining with ;
• ⬜ Pipes (|)
• ⬜ I/O redirection (>, <)
• ⬜ Custom help command

student$ ./target/release/kinda_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
$ echo $HOME
/home/student
$ mkdir test_dir
$ ls
test_dir
$ rm -r test_dir
$ exit
student$

This project is evaluated based on:

This project is part of an educational assignment.

• AyyoubMh48 - GitHub