https://github.com/izenynn/mini-shell
This project aims to recreate most of the bash shell.
https://github.com/izenynn/mini-shell
42 42born2code 42minishell bash bash-like c linux linux-shell macos macos-shell minishell shell
Last synced: about 1 year ago
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This project aims to recreate most of the bash shell.
- Host: GitHub
- URL: https://github.com/izenynn/mini-shell
- Owner: izenynn
- License: gpl-3.0
- Created: 2021-12-20T15:43:21.000Z (over 4 years ago)
- Default Branch: main
- Last Pushed: 2023-04-04T14:36:39.000Z (about 3 years ago)
- Last Synced: 2025-03-28T03:11:48.820Z (about 1 year ago)
- Topics: 42, 42born2code, 42minishell, bash, bash-like, c, linux, linux-shell, macos, macos-shell, minishell, shell
- Language: C
- Homepage:
- Size: 445 KB
- Stars: 4
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# minishell
## Contents
- [Info](#info)
- [How to use](#how-to-use)
- [Clone repo and submodules](#clone-repo-and-submodules)
- [Linux dependencies](#linux-dependencies)
- [MAC dependencies](#mac-dependencies)
- [Compile and execute](#compile-and-execute)
- [Install](#install)
- [Features](#features)
- [Built-in commands](#built-in-commands)
- [Aproach](#aproach)
- [Shell grammar](#shell-grammar)
- [Screenshots](#screenshots)
## Info
This project aims to recreate most of the bash shell.
- Status: finished
- Result: 125%
- Observations:
- It is compatible with Linux and Mac OS.
- It does not use `VT100` escape characters.
*developed by: [izenynn](https://github.com/izenynn) and [0xk0sta](https://github.com/0xk0sta)*
## How to use
### Clone repo and submodules
```sh
git clone --recurse-submodules https://github.com/izenynn/minishell.git
```
### Linux dependencies
Install readline library:
- On Debian based platforms, like Ubuntu:
```sh
sudo apt install libreadline-dev
```
- Platforms with `yum`, like SUSE:
```sh
yum install readline-devel
```
- For other platform please search for the package name on google, thx :)
### MAC dependencies
- Install readline library:
```sh
brew install readline
```
### Compile and execute
Run `make` (make rules: `all`, `clean`, `fclean` and `re`)
```sh
cd ./minishell && make
```
Execute the `./minishell` binary generated after running `make`
```sh
./minishell
```
### Install
To install minishell in your machine and be able to use it in any directory like any other command, run `make install` (make sure you have the correct access rights).
```sh
sudo make install
```
To change the install directory specify the `BIN_DIR` variable on make
```sh
sudo make install -D 'BIN_DIR=/usr/local/bin'
```
## Features
- Recreates most of the bash shell.
- support for config file `.minishrc` (like bash `.bashrc`).
- comments with `#` (NOTE: `#` must be at the start of the line).
- Pipes `|` works like in bash.
- Redirections `<`, `>`, `<<`, `>>` work like in bash.
- `;`, `&&` and `||` work like in bash.
- Parenthesis: `(` and `)` works with `&&`, `||` and `;` for priorities.
- `$?` works like in bash.
- wildcards `*` and `?` works for the current directory.
- Handle signals: `Ctrl-C`, `Ctrl-D` and `Ctrl-\` like in bash.
- Enviroments variables.
- Arrow keys.
- History (command history).
- Auto-complete with tab key.
### Built-in commands
- `echo`
- `cd`
- `pwd`
- `export`
- `unset`
- `env`
- `exit`
## Aproach
minishell is formed by 3 components:
1. Lexical analyzer: parse the input line into tokens.
2. Parser: parse tokens into an abstract syntax tree (ast).
3. Executor: execute the commands
To see how it works, go to `src/main/handle_line.c`, uncomment the functions `print_ast` and `print_tokens`, in line 18 and 78, add the following lines to the `handle_line` function and run `make` again:
```diff
void handle_line(char *line, t_bool is_alloc)
{
t_lexer lex;
t_ast *ast;
int ret;
ast = NULL;
if (check_line(line, is_alloc) == 1)
return ;
ret = lexer_build(line, ft_strlen(line), &lex);
if (ret <= 0)
{
if (ret == 0 && g_sh.tokdel == FALSE)
write(STDERR_FILENO, "error: syntax error\n", 20);
free_line(line, is_alloc);
lexer_del(&lex);
return ;
}
free_line(line, is_alloc);
+ print_tokens(&lex);
if (lex.n_toks == 0 || parse(&lex, &ast))
{
free_all(&lex, ast);
return ;
}
+ print_ast(ast, 0); printf("------------------------------------\n");
if (exec_heredoc(ast) == 0)
exec_ast(ast);
free_all(&lex, ast);
}
```
Example:
```txt
minishell$ "invalid command" || (echo hello && echo world!)
------------------------------------
TOKENS:
n_tok: 10
type: -1, data: invalid command
type: 124, data: |
type: 124, data: |
type: 40, data: (
type: -1, data: echo
type: -1, data: hello
type: 38, data: &
type: 38, data: &
type: -1, data: echo
type: -1, data: world!
type: 41, data: )
type: 0, data:
------------------------------------
AST:
type: arg, data: world!
type: cmd, data: echo
type: &&
type: arg, data: hello
type: cmd, data: echo
type: ||
type: cmd, data: invalid command
------------------------------------
invalid command: command not found
hello
world!
minishell$
```
## Shell grammar
```txt
Grammar
: ';'
| ';'
|
;
: '&&'
| '||'
|
| '(' ')' '&&'
| '(' ')' '||'
| '(' ')'
;
: '(' ')' '|'
| '|'
| '(' ')'
|
;
:
;
: [name]
| [token]
| [redir]
| (null)
;
:
|
;
: '<<' [file]
| '<' [file]
;
: '>>' [file]
| '>' [file]
;
```
## Screenshots
##
[](https://forthebadge.com)
[](https://forthebadge.com)