👚 Microshell

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A minimal shell built in C as part of the ALX Software Engineering curriculum.

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📚 Project Description

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This project is a simplified version of a Unix shell. It supports executing basic commands, chaining commands with ;, and connecting commands using pipes |.

The goal is to gain a deep understanding of process creation, execution, file descriptors, and inter-process communication using system calls like fork, execve, pipe, and wait.

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🚀 Features

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• Execute simple shell commands (e.g., ls, echo, pwd)
• Support for command separators ;
• Support for pipelines using |
• Built-in support for cd
• Proper error handling and exit codes
• Manual path resolution using /bin/ prefix

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⚙️ Usage

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./microshell ls -l \| grep .c \; echo done

This command will:

1. List all files using ls -l
2. Filter output through grep .c using a pipe
3. After the pipe finishes, echo done is executed

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🔧 How it works

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1. Parsing The program iterates over arguments and identifies separators | and ;

2. Built-in Handling If the command is cd, it is handled internally using chdir()

3. Execution

   • A child process is created with fork()
   • The command is run with execve() (after prepending /bin/ manually)
   • If piped, the input/output is redirected using pipe() and dup2()

4. Error Handling Custom error messages are printed to stderr if something fails

5. Synchronization The parent waits for child processes with waitpid()

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📁 File Structure

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microshell/
│
├── microshell.c       # All logic: parsing, execution, piping, etc.
├── Makefile
└── README.md

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📌 System Calls Used

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• fork()
• execve()
• pipe()
• dup2()
• waitpid()
• chdir()
• write()
• malloc()

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🧐 What I Learned

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• Deep understanding of how Unix shells work internally
• Handling built-in commands manually
• Working with file descriptors and pipes
• Error handling and memory allocation in C

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👨‍💻 Author

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Made with ❤️ by Samir — @Samir-Ouaammou Project part of ALX SE Program

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📝 License

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This project is licensed under the MIT License - see the LICENSE file for details.