Minishell

Overview

Minishell is a simple shell implementation that allows users to interact with their operating system through a command-line interface. It supports various features such as command execution, history management, redirections, pipes, environment variable expansion, and more.

Table of Contents

1. Overview
2. Features
   • Basic Shell Functionality
   • Command Execution
   • Input Handling
   • Redirections
   • Pipes
   • Environment Variable Handling
   • Special Variables
   • Interactive Mode
   • Built-in Commands
   • Additional Features
3. Usage
4. Makefile Commands
5. External Functions
6. Libft

Features

Basic Shell Functionality

• Display a prompt when waiting for a new command.
• Maintain a working history for previously entered commands.

Command Execution

• Search and launch the right executable based on the PATH variable or using a relative or absolute path.
• Avoid using more than one global variable to indicate a received signal, ensuring signal handlers do not access main data structures.

Input Handling

• Do not interpret unclosed quotes or special characters not required by the subject (e.g., backslash or semicolon).
• Handle single quotes (') to prevent the shell from interpreting meta-characters in the quoted sequence.
• Handle double quotes (") to prevent the shell from interpreting meta-characters in the quoted sequence except for $ (dollar sign).

Redirections

• < should redirect input.
• > should redirect output.
• << should read input until a line containing the specified delimiter without updating the history.
• >> should redirect output in append mode.

Pipes

• Implement pipes (|) where the output of each command in the pipeline is connected to the input of the next command via a pipe.

Environment Variable Handling

• Handle environment variables ($) that expand to their values.

Special Variables

• Handle $?, which expands to the exit status of the most recently executed foreground pipeline.

Interactive Mode

• Handle ctrl-C to display a new prompt on a new line.
• Handle ctrl-D to exit the shell.
• Handle ctrl-\ with no specific action.

Built-in Commands

• echo with option -n
• cd with only a relative or absolute path
• pwd with no options
• export with no options
• unset with no options
• env with no options or arguments
• exit with no options

Additional Features

• Heredoc expands environment variables.
• Colored prompt to indicate whether the last status code was 0 or not.
• If Minishell is launched without an environment, it creates one that includes: SHLVL, _, PATH, PWD.

Usage

Compile the program using the provided Makefile:

make

Run Minishell:

./minishell

Makefile Commands

• make: Compile the program.
• make all: Same as make.
• make clean: Remove object files.
• make fclean: Remove object files and the executable.
• make re: Rebuild the program from scratch.

External Functions

• readline, rl_clear_history, rl_on_new_line, rl_replace_line, rl_redisplay, add_history, printf, malloc, free, write, access, open, read, close, fork, wait, waitpid, wait3, wait4, signal, sigaction, sigemptyset, sigaddset, kill, exit, getcwd, chdir, stat, lstat, fstat, unlink, execve, dup, dup2, pipe, opendir, readdir, closedir, strerror, perror, isatty, ttyname, ttyslot, ioctl, getenv, tcsetattr, tcgetattr, tgetent, tgetflag, tgetnum, tgetstr, tgoto, tputs

Libft

Libft functions are authorized for use.

Feel free to explore and enjoy the Minishell experience!