🚀 Custom UNIX/LINUX Shell

This is a simple custom shell implemented in C++ that supports basic Unix commands, input/output redirection, piping, and command history.

🌟 Features

• 📂 Execute common Unix commands like ls, pwd, mkdir, etc.
• 🔄 Input and output redirection using <, >, and 2>.
• 🚰 Piping between commands using |.
• ⏳ Background command execution using &.
• 📜 Command history and recall using !! and !n.
• 🚪 Creation and usage of named pipes (FIFOs) using mkfifo.

🏁 Getting Started

📋 Prerequisites

• 🛠️ A C++ compiler (g++ recommended)
• 🐧🍏 Unix-like operating system (Linux, macOS)

🖥️ Compilation

To compile the shell, use the following command:

g++ -o custom_shell custom_shell.cpp

▶️ Running the Shell

After compiling, you can run the shell with:

./custom_shell

💡 Usage

📝 Basic Commands

You can run basic Unix commands like pwd, ls, mkdir, etc. Example:

( Enter Command ) : pwd

↪️ ↩️ Input/Output Redirection

Redirect input from a file using <, and output to a file using >. Example:

( Enter Command ) : sort < input.txt > output.txt

Redirect standard error using 2>. Example:

( Enter Command ) : ls non_existent_file 2> error.txt

🔗 Piping

Use | to pipe the output of one command to another. Example:

( Enter Command ) : sort testing.txt | grep anyword | cat > a.txt

🔄 Background Execution

Run a command in the background using &. Example:

( Enter Command ) : sort testing.txt > sorted.txt &

📜 Command History

• View command history with history.
• Recall the most recent command with !!.
• Recall a specific command with !n (where n is the command number).

🚪 Named Pipes (FIFOs)

Create a named pipe using mkfifo. Example:

( Enter Command ) : mkfifo fifo1

Write to and read from a named pipe:

( Enter Command ) : cat fifo1&
( Enter Command ) : echo "hello" > fifo1

💻 Example Commands

• pwd
• ls
• ls -l
• mkdir folderName
• exit
• &command (e.g., &pwd)
• sort < input.txt > output.txt
• cd directoryPath
• ls non_existent_file 2> error.txt
• man ls > ls.dat
• cat input.txt
• cat input.txt output.txt > combined.txt
• tr -s '[:space:]' '\n' < sortingFile.txt
• sort testing.txt | grep anyword | cat > a.txt
• sort testing.txt | grep anyword > a.txt | wc -l
• sort ls.dat | tee a.txt
• touch newFile.txt
• nano newFile.txt
• echo "coding is fun" > fifo1
• rm fifo1
• echo "code"
• sort testing.txt | tee a.txt
• sort testing.txt | tee a.txt | wc -l
• sort a.txt > fifo1
• ls | tee listing.txt | grep .cpp

📝 Note on FIFOs

When writing data to a FIFO, the write will block until another process reads from it. Ensure that there is a process reading from the FIFO to avoid indefinite blocking.

🌍 Contributing

Contributions are welcome! Feel free to open issues or submit pull requests. 🤝

📄 License

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

📥 Clone the Repository

git clone https://github.com/maazkhan75/CustomLinuxShell.git

📸 Screenshots