minishell/src/subst/wildcard_exp.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   wildcard_exp.c                                     :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: jguelen <jguelen@student.42.fr>            +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2025/02/23 15:02:59 by jguelen           #+#    #+#             */
/*   Updated: 2025/03/08 17:25:03 by jguelen          ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "ft_printf.h"
#include "subst.h"

/*
** TODO Pre-process file_pattern worddesc for a congruent marker string
** TODO Post-process to sort the resulting list regarding ascii order
*/
/******************************************************************************/
/* NOTE: The use of errno and the setting of it was OKed by Alexandru in this */
/* context.                                                                   */
/******************************************************************************/
/*
** Returns a directory stream corresponding to the current directory.
**
*/
DIR	*open_current_dir(void)
{
	char	*cur_dir_path;
	size_t	size;
	DIR		*dir;

	size = PATH_SIZE_INIT;
	cur_dir_path = malloc(size * sizeof(char));
	if (!cur_dir_path)
		return (NULL);
	while (getcwd(cur_dir_path, size) == NULL)
	{
		if (errno != ERANGE)
			return (NULL);
		free(cur_dir_path);
		size *= 2;
		cur_dir_path = malloc(size * sizeof(char));
		if (!cur_dir_path)
			return (NULL);
	}
	errno = 0;
	dir = opendir(cur_dir_path);
	free(cur_dir_path);
	return (dir);
}

/*
**
*/
static t_wordlist	*add_file_to_list(t_wordlist **list, char *filename)
{
	t_worddesc	*file_desc;
	char		*copy;

	copy = ft_strdup(filename);
	if (!copy)
		return (wordlist_destroy(*list), NULL);
	file_desc = worddesc_create(copy, '\0', NULL); ///////////CHECK IF CONFLICT
	if (!file_desc)
	{
		wordlist_destroy(*list);
		return (NULL);
	}
	*list = wordlist_push(*list, file_desc);
	return (*list);
}

/*
** TODO Check if return value correct regarding the manual specifically the
** following:
** cf Bash scans each word for the character '*'.
**
** If one of these characters appears, and is not quoted, then the word is
** regarded as a PATTERN, and replaced with an alphabetically sorted list
** of filenames matching the pattern (see: Pattern Matching). If no matching
** filenames are found, the word is left unchanged.
** --> TODO this function should be provided with a properly pre-processed
** file_pattern where file_pattern->matcher denotes the quoted wildcards
** but the quotes themselves unquoted have been removed from word in a manner
** keeping the relationship between word and marker coherent.
*/
/*
** A function designed to present all possible * or ? filename expansions
** for the current directory. (? is not asked by the subject).
** Does not take into account any other wildcard and does only search the
** current working directory.
** @PARAM A C compliant character string representing a pattern for a filename.
** @RETURN Returns a wordlist for which each entry corresponds to a filename
** that matches pattern->word if any file matches in the current directory.
** Otherwise return file_pattern itself if nothing matches the perceived
** pattern. This list should be alphabetically sorted.
** TODO sort the list in growing ascii order. (use of strcmp probable)
*/
t_wordlist	*expand_star(t_worddesc *file_pattern)
{
	struct dirent	*new;
	DIR				*current_dir;
	t_wordlist		*file_wordlist;

	current_dir = open_current_dir();
	if (current_dir == NULL)
		return (NULL);
	file_wordlist = NULL;
	errno = 0;
	new = readdir(current_dir);
	while (new)
	{
		if (fits_pattern(new->d_name, file_pattern))
		{
			if (add_file_to_list(&file_wordlist, new->d_name) == NULL)
				return (NULL);
		}
		errno = 0;
		new = readdir(current_dir);
	}
	if (errno)
		return (wordlist_destroy(file_wordlist), NULL);
	if (!file_wordlist)
		wordlist_push(file_wordlist, file_pattern);
	return (wordlist_quicksort(file_wordlist));
}