This project is about creating a simple shell. Yes, your own little bash. You will learn a lot about processes and file descriptors

Albagar4 (Built-ins, Environment variables)
Alvega-g (Parser-lexer, Executor)

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Mandatory part

Program name	minishell
Turn in files	Makefile, *.h, *.c
Makefile	NAME, all, clean, fclean, re
Arguments
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 authorized	Yes
Description	Write a shell

Your shell should:

• Display a prompt when waiting for a new command.
• Have a working history.
• Search and launch the right executable (based on the PATH variable or using a relative or an absolute path).
• Avoid using more than one global variable to indicate a received signal. Consider the implications: this approach ensures that your signal handler will not access your main data structures.

Be careful. This global variable cannot provide any other information or data access than the number of a received signal. Therefore, using "norm" type structures in the global scope is forbidden.

• Not interpret unclosed quotes or special characters which are not required by the subject such as \ (backslash) or ; (semicolon).
• Handle ’ (single quote) which should prevent the shell from interpreting the metacharacters in the quoted sequence.
• Handle " (double quote) which should prevent the shell from interpreting the metacharacters in the quoted sequence except for $ (dollar sign).
• Implement redirections:
  • < should redirect input.
  • > should redirect output.
  • << should be given a delimiter, then read the input until a line containing the delimiter is seen. However, it doesn’t have to update the history!
  • >> should redirect output in append mode.
• Implement pipes (| character). The output of each command in the pipeline is connected to the input of the next command via a pipe.
• Handle environment variables ($ followed by a sequence of characters) which should expand to their values.
• Handle $? which should expand to the exit status of the most recently executed foreground pipeline.
• Handle ctrl-C, ctrl-D and ctrl-\ which should behave like in bash.
• In interactive mode:
  • ctrl-C displays a new prompt on a new line.
  • ctrl-D exits the shell.
  • ctrl-\ does nothing.
• Your shell must implement the following builtins:
  • 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

The readline() function can cause memory leaks. You don’t have to fix them. But that doesn’t mean your own code, yes the code you wrote, can have memory leaks.

You should limit yourself to the subject description. Anything that is not asked is not required. If you have any doubt about a requirement, take bash as a reference.

Bonus part

Your program has to implement:

• && and || with parenthesis for priorities.
• Wildcards * should work for the current working directory.
• Correct implementation of single and double quotes when expanding variables and nesting quotes.

How to run

Clone this repository to your working directory by running the following commands:

git clone https://github.com/ColmiiK/minishell.git
cd minishell
make
./minishell

The readline library is required to run this program.