Minishell

A simple shell built in C that replicates basic Bash functionality.

---

Core Functions

1. main_loop

The main_loop function is the main control of the shell. It continuously waits for user input, and tokenizes it.

void	main_loop(t_env **env)
{
	t_token	*token_list;

	token_list = NULL;
	while (1)
	{
		read_and_tokenize(env, &token_list);
		if (token_list)
		{
			main_process(env, token_list);
			ft_tokens_free(token_list);
			token_list = NULL;
		}
	}
}

• Purpose:

  • Input Handling: The loop waits for user input in read_and_tokenize, which converts the input into a linked list of tokens.

• Token Structure:

  • Tokens represent parsed elements of the user input, including commands, arguments, operators, pipes, exit status($?), and redirections.

typedef enum e_token_type
{
	WORD,
	S_QUOTE,
	D_QUOTE,
	SPACES,
	ENV,
	PIPE,
	RED_IN,
	RED_OUT,
	RED_APP,
	HERE_DOC,
	EXIT_STATUS
}						t_token_type;

typedef struct s_token
{
	char				*value;
	t_token_type		type;
	struct s_token		*next;
}						t_token;

---

2. main_process

The main_process function is responsible for transforming the list of tokens into a list of commands, setting paths, and sending the commands to the executor.

void	main_process(t_env **env, t_token *token_list)
{
	t_command	*cmd;

	cmd = NULL;
	if (token_list)
	{
		cmd = fill_command(token_list, *env);
		if (cmd)
		{
			set_path(&cmd);
			execution(&cmd, env);
			free_cmd(cmd);
			cmd = NULL;
		}
	}
}

• Purpose:
  • After checking for syntax errors (such as mismatched quotes, redirections, and pipes), the fill_command function converts the token list into a list of commands. Each command has its own list of redirections.

typedef struct s_command
{
	char				*name;
	char				**args;
	char				*path;
	t_red				*in;
	t_red				*out;
	int					fd;
	struct s_command	*next;
}

• After building the commands list, it is passed to the execution function for further processing.

Run

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

---

• This project was made with the collaboration of @battagi.