get_next_line.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   get_next_line.c                                    :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: dshatilo <dshatilo@student.hive.fi>        +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2023/11/09 16:39:03 by dshatilo          #+#    #+#             */
/*   Updated: 2023/11/15 16:58:24 by dshatilo         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "get_next_line.h"

char	*get_string(char *s, char *buffer, int fd, ssize_t bytes);

char	*ft_get_line(char *str);

char	*dealloc(char *s, char *line);

char	*get_next_line(int fd)
{
	static char	*string;
	char		*buffer;
	char		*line;

	if (fd < 0 || BUFFER_SIZE <= 0 || BUFFER_SIZE >= (size_t)(-2))
		return (0);
	buffer = 0;
	string = get_string(string, buffer, fd, 1);
	if (!string)
		return (0);
	line = ft_get_line(string);
	if (!line)
	{
		string = ft_free(string);
		return (0);
	}
	string = dealloc(string, line);
	return (line);
}

char	*get_string(char *s, char *buffer, int fd, ssize_t bytes)
{
	s = check_string(s);
	if (!s)
		return (0);
	while ((s && !ft_strchr(s, '\n')) && bytes != 0)
	{
		buffer = (char *)malloc(sizeof(char) * BUFFER_SIZE);
		if (!buffer)
			return (ft_free(s));
		bytes = read(fd, buffer, BUFFER_SIZE);
		if (bytes == -1)
		{
			free(s);
			return (ft_free(buffer));
		}
		if (!bytes)
		{
			if (*s == 0)
				s = ft_free(s);
			free(buffer);
			return (s);
		}
		s = add_to_string(s, buffer, bytes);
		free (buffer);
	}
	return (s);
}

char	*ft_get_line(char *str)
{
	char	*line;
	size_t	line_len;

	line_len = 0;
	while (str[line_len] != 0 && str[line_len] != '\n')
		line_len++;
	if (str[line_len] == '\n')
		line_len++;
	line = (char *)malloc(sizeof(char) * (line_len + 1));
	if (!line)
		return (0);
	line[line_len] = 0;
	ft_strncpy(line, str, line_len);
	return (line);
}

char	*dealloc(char *s, char *line)
{
	char	*new_s;
	size_t	s_len;
	size_t	n_len;
	size_t	line_len;

	s_len = 0;
	line_len = 0;
	while (line[line_len] != 0)
		line_len++;
	while (s[s_len] != 0)
		s_len++;
	n_len = s_len - line_len;
	if (!n_len)
		return (ft_free(s));
	new_s = (char *)malloc(sizeof(char) * (n_len + 1));
	if (!new_s)
		return (ft_free(s));
	ft_strncpy(new_s, s + line_len, n_len);
	new_s[n_len] = 0;
	free(s);
	return (new_s);
}