Custom Shell

Create the Shell

Create a file named custom_shell.py and add the following code:

pythonCopy codeimport os
import subprocess

class CustomShell:
def __init__(self):
    self.running = True
def run(self):
    while self.running:
        try:
            command = input(f"{os.getcwd()}$ ").strip()
            self.process_command(command)
        except KeyboardInterrupt:
            print("\nExiting the shell.")
            self.running = False
def process_command(self, command):
    if command.lower() in ['exit', 'quit']:
        self.running = False
        return
    elif command.startswith('cd '):
        self.change_directory(command[3:])
    else:
        self.execute_command(command)
def change_directory(self, path):
    try:
        os.chdir(path)
        print(f"Changed directory to {os.getcwd()}")
    except Exception as e:
        print(f"cd: {e}")
def execute_command(self, command):
    try:
        # Execute the command
        result = subprocess.run(command, shell=True, check=True, text=True, capture_output=True)
        print(result.stdout)
    except subprocess.CalledProcessError as e:
        print(f"Error: {e.stderr.strip()}")
if __name__ == "__main__":
shell = CustomShell()
shell.run()

Step 2: Running the Custom Shell

1. Open your terminal (or command prompt).
2. Navigate to the directory where you saved custom_shell.py.
3. Run the script using the command:bashCopy codepython custom_shell.py

How It Works

• Command Input: The shell prompts you to enter a command.
• Command Processing:
  • Exit Command: You can type exit or quit to exit the shell.
  • Change Directory: Use cd <directory> to change the current working directory.
  • Execute Command: Any other command is executed using the subprocess module.
• Error Handling: The shell handles errors gracefully, providing feedback if a command fails.

Example Usage

1. Change Directory: Type cd path/to/directory to navigate to a different directory.
2. Execute Commands: Type commands like ls (or dir on Windows) to list files, or echo Hello World to print a message.
3. Exit: Type exit or quit to close the shell.