BraianPerez97 / holbertonschool-shell

Holberton School Simple Shell Project

Introduction

This project is a simple UNIX command line interpreter developed as part of the Holberton School curriculum. The goal is to create a basic shell that can handle command lines with or without arguments, execute commands, and implement built-in functionalities.

Table of Contents

• General Information
• Requirements
• Usage
• Compilation
• Testing
• Tasks
• Contributions

General Information

This shell project covers various aspects, including:

• Original UNIX Contributors:

  • The original Unix operating system was designed and implemented by Ken Thompson.
  • The first version of the UNIX shell was written by Ken Thompson.
  • The B programming language, the direct predecessor to the C programming language, was invented by Ken Thompson.

• Understanding the Shell:

  • The shell is an interface that allows users to interact with the operating system.
  • A shell works by taking user input, interpreting commands, and executing them.
  • It uses processes and system calls to perform various operations.

• Process Management:

  • A pid (Process ID) is a unique identifier for a process.
  • A ppid (Parent Process ID) is the ID of the parent process.
  • Processes can be created using the fork system call.

• Environment Manipulation:

  • The environment of the current process can be manipulated using system calls and functions.

• Function vs. System Call:

  • The difference between a function and a system call lies in their implementation and purpose.

• Executing Programs:

  • Programs can be executed using the execve system call.

• Shell Path and Execution:

  • The shell uses the PATH variable to find the location of programs.

• Handling Process Termination:

  • The shell can suspend execution until one of its children terminates.

• EOF (End-of-File):

  • EOF is a condition that indicates the end of input.

Requirements

• Allowed Editors: vi, vim, emacs
• Compilation: gcc -Wall -Werror -Wextra -pedantic -std=gnu89 *.c -o hsh
• Memory Leaks: The shell should not have any memory leaks.
• Code Style: Code should adhere to the Betty style.

Usage

To run the shell in interactive mode:

``bash $ ./hsh ($) /bin/ls hsh main.c shell.c ($) ($) exit $

To run the shell in non-interactive mode:

bash

$ echo "/bin/ls" | ./hsh hsh main.c shell.c test_ls_2 $ $ cat test_ls_2 /bin/ls /bin/ls $ $ cat test_ls_2 | ./hsh hsh main.c shell.c test_ls_2 hsh main.c shell.c test_ls_2 $

Compilation

Compile the shell using the following command:

bash

$ gcc -Wall -Werror -Wextra -pedantic -std=gnu89 *.c -o hsh

Testing

Ensure that your shell produces the same output as /bin/sh and has the same error output.

Tasks

Task 0: README, man, AUTHORS

Write a README.md file.
Write a man page for your shell (man_1_simple_shell).
Include an AUTHORS file listing all contributors.

Task 1: Betty would be proud

Write code that passes the Betty checks.

Task 2: Simple shell 0.1

Develop a basic UNIX command line interpreter.

Task 3: Simple shell 0.2

Handle command lines with arguments.

Task 4: Simple shell 0.3

Handle the PATH.
Avoid calling fork if the command doesn't exist.

Task 5: Simple shell 0.4

Implement the exit built-in.
Usage: exit

Task 6: Simple shell 1.0

Implement the env built-in.
Usage: env

Task 9: Simple shell 0.1.1

Write your own getline function.

Task 10: Simple shell 0.2.1

Do not use strtok.

Task 11: Simple shell 0.4.1

Handle arguments for the built-in exit.
Usage: exit status

Contributions

Contribute to the test suite for the shell project.

Author

Braian Perez - [e-mail]