https://github.com/colmiik/minishell

A simple recreation of bash in C
https://github.com/colmiik/minishell

42school bash minishell

Last synced: about 1 month ago
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A simple recreation of bash in C

• Host: GitHub
• URL: https://github.com/colmiik/minishell
• Owner: ColmiiK
• Created: 2024-02-20T16:19:56.000Z (over 2 years ago)
• Default Branch: master
• Last Pushed: 2024-07-08T11:35:33.000Z (almost 2 years ago)
• Last Synced: 2025-02-21T15:51:32.577Z (over 1 year ago)
• Topics: 42school, bash, minishell
• Language: C
• Homepage:
• Size: 228 KB
• Stars: 1
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

          


    

    

    


    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)

		

        


	

	    

    

    




---

# 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](https://www.gnu.org/savannah-checkouts/gnu/bash/manual/) 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:

```bash

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

cd minishell

make

./minishell

```

### The readline library is required to run this program.