Unix-cli

This project is aimed at creating a simple shell, similar to Bash. This project enhanced my understanding of processes and file descriptors in Unix-like operating systems.

How to use it

git clone https://github.com/2iaad/Unix-cli 2iaad && cd 2iaad && make && ./minishell

Overview

Unix-cli is a program that mimics the behavior of a command-line interpreter, accepting and executing commands while offering core shell functionalities. Designed to follow Unix standards, it handles parsing, redirections, pipes, and some built-in commands, providing an educational experience in building a CLI from scratch and understanding how commands are executed behind the scenes.

Key Shell Functionalities

1. Parsing and Execution Flow

Unix-cli’s parsing system involves tokenizing input, recognizing built-in and external commands, and handling arguments and operators. This includes:

1. Lexical Analysis: Breaking down commands using libft functions (e.g., ft_split), managing quotes, special characters, and whitespace.
2. Syntax Parsing: Identifying commands, arguments, and operators like pipes (|) and redirections (>, <).
3. Execution Handling: Executing built-in commands or external programs using execve.

2. Redirections and Pipes

Unix-cli implements pipes and redirections to link commands and manage I/O efficiently. Lets take this example:

ls | sort | tail | awk

• Redirection Management: Sets up file descriptors to redirect input/output as needed, using dup2 to remap them for specific commands.
• Pipes: Links multiple commands, passing output from one command as input to the next using file descriptors.

3. Signal Handling

Unix-cli responds to Unix signals (SIGINT, SIGQUIT) to manage command interruption and keep the interface responsive. We can say that it just an action that can be done depending on a signal thrown.

• Command Interruption: Stops currently executing commands without crashing the shell.
• Prompt Control: Clears and redisplays the prompt on specific signals.

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What i have learned

Developing and using essential programming concepts like memory management, IPC (inter process communication), formatted output, and file I/O. This project game me programming skills that im pretty sure will help build larger projects.

Thanks for reading sa7bi ;) Enjoy!