Lazy Shell

Lazy Shell is a lightweight, educational Unix-like shell implemented in C. It provides a simple command-line interface, supports built-in commands, pipelines, I/O redirection, background job control, and basic signal handling.

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📁 File Structure

Lazy_Shell/
├── include/
│   └── shell.h               # Public headers and declarations
├── src/
│   ├── command_executor.c    # Fork/exec logic for external commands & built-ins dispatcher
│   ├── job_controller.c      # Background/foreground job management and status checking
│   ├── parser.c              # Command-line parsing (splitting tokens & detecting pipelines)
│   ├── pipeline_executor.c   # Setting up pipes and executing two-stage pipelines
│   ├── redirection_handler.c # Handling `<` and `>` I/O redirection
│   ├── signal_handler.c      # Installing signal handlers for SIGINT/SIGTSTP
│   └── shell.c               # Main loop, prompt, and dispatch logic
├── tests/                    # (Optional) unit/integration test cases
├── Makefile                  # Build rules for compiling the shell
└── README.md                 # This file

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🚀 Features

• Built-in commands:
  • cd <dir>: Change the current working directory
  • help : Display a help message and list of built-ins
  • exit : Exit the shell
• External commands: Fork + execvp() support for any system executable.
• Pipelines: Connect two commands via |, e.g. ls -l | grep ".c".
• I/O Redirection:
  • < input.txt : Redirect stdin from file
  • > output.txt : Redirect stdout to file (overwrite)
• Job Control:
  • Background jobs with &
  • Ctrl-C (SIGINT) kills the running child process without exiting the shell
  • Ctrl-Z (SIGTSTP) suspends the child process and adds it to the job list
• Job Table: Tracks up to 100 jobs, prints status messages when jobs stop or finish.
• Signal Handling: The shell itself ignores SIGINT/SIGTSTP; children reset to defaults.

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🛠️ Build & Run

1. Clone the repo

   git clone https://github.com/yourusername/Lazy_Shell.git
   cd Lazy_Shell

2. Compile

   make

   This produces the lazy_shell executable in bin/ (or the project root).

3. Run

   ./shell

   You should see the ASCII welcome banner and the prompt Lazy shell $ .

4. Clean

   make clean

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🧪 Tests

If you add test cases in the tests/ directory, you can automate running them via:

make test

(No tests are included by default.)

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✍️ Contributing

Contributions, bug reports, and feature requests are welcome! Please open an issue or submit a pull request.

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📄 License

This project is released under the MIT License. See LICENSE for details.