Unix Shell

A custom, basic Unix shell implementation written in C++ (C++23).

Features

This shell provides a basic command-line interface with support for several built-in commands and the ability to execute external programs found in your system's $PATH.

• Built-in Commands:

  • exit: Exits the shell.
  • echo: Prints text to the standard output. Handles single quotes ('), double quotes ("), and escape characters (\).
  • pwd: Prints the current working directory.
  • cd: Changes the current directory. Supports cd ~ (home directory), cd - (previous directory), and standard paths.
  • type: Indicates how a command name would be interpreted (e.g., shell builtin or an external executable path).

• External Command Execution:

  • Executes any valid command found in the directories listed in the $PATH environment variable.

• I/O Redirection:

  • > or 1>: Redirect standard output to a file (overwrite).
  • >> or 1>>: Redirect standard output to a file (append).
  • 2>: Redirect standard error to a file (overwrite).
  • 2>>: Redirect standard error to a file (append).

Building the Shell

To compile the shell, you need a C++ compiler that supports C++23 (like g++).

Run the following command in the project root:

make

This will compile src/main.cpp and generate an executable named shell.

Running the Shell

After building, you can start the shell by running:

./shell

You will be greeted with the $ prompt, ready to accept your commands.

Cleaning Up

To remove the compiled executable, run:

make clean