This is a simple Unix shell program implemented in C, supporting multi-processing. The shell allows users to execute commands, both built-in and external, and provides features such as environment variable handling, background process execution, and logging of child process terminations.

• Execute internal shell commands such as cd, echo, and export.
• Execute external commands with or without arguments.
• Support background execution of commands using the & symbol.
• Handle environment variables and evaluate expressions.
• Log child process terminations to a file.
• Exit the shell gracefully using the exit command.

To compile and run the shell program, use the following commands:

gcc Shell.c -o Shell.o && ./Shell.o

Once the shell is running, you can enter commands just like in a regular Unix shell. You can use built-in commands (cd, echo, export) or external commands (e.g., ls, mkdir, firefox). To exit the shell, simply type exit.

• The shell parses user input, evaluates expressions, and executes commands accordingly.
• Built-in commands are handled internally within the shell.
• External commands are executed as separate processes using fork() and execvp().
• Background processes are supported by appending & to the command.
• Child process terminations are logged using a signal handler for SIGCHLD.
• Environment variables are stored and evaluated during command execution.

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