libs: added libft

libft/get_next_line.c

@@ -0,0 +1,128 @@
+/* ************************************************************************** */
+/*                                                                            */
+/*                                                        :::      ::::::::   */
+/*   get_next_line.c                                    :+:      :+:    :+:   */
+/*                                                    +:+ +:+         +:+     */
+/*   By: jguelen <marvin@42.fr>                     +#+  +:+       +#+        */
+/*                                                +#+#+#+#+#+   +#+           */
+/*   Created: 2024/11/01 15:08:34 by jguelen           #+#    #+#             */
+/*   Updated: 2025/01/06 14:37:50 by jguelen          ###   ########.fr       */
+/*                                                                            */
+/* ************************************************************************** */
+
+#include "libft.h"
+#include "get_next_line.h"
+
+/*Finds the next \n in the buffer and sets *copy_til to it and returns 1 if 
+found. If no \n is found, returns 0 and sets copy_til to buffer->end if
+the buffer is not empty*/
+static int	find_eol(t_buffer *buffer, char **copy_til)
+{
+	size_t	i;
+
+	i = 0;
+	if (buffer->start == NULL)
+		return (0);
+	while (buffer->start + i <= buffer->end)
+	{
+		if (buffer->start[i] == '\n')
+		{
+			*copy_til = buffer->start + i;
+			return (1);
+		}
+		i++;
+	}
+	*copy_til = buffer->end;
+	return (0);
+}
+
+static int	line_aggregation(t_buffer *buffer, char **copy_til, char **line,
+								size_t *len)
+{
+	char	*new;
+	size_t	old_len;
+
+	old_len = *len;
+	if (!buffer->start)
+		return (1);
+	*len += *copy_til - buffer->start + 1;
+	new = malloc((*len + 1) * sizeof(char));
+	if (!new)
+	{
+		free(*line);
+		line = NULL;
+		return (0);
+	}
+	if (*line)
+		ft_memcpy(new, *line, old_len);
+	ft_memcpy(new + old_len, buffer->start, *len - old_len);
+	new[*len] = '\0';
+	buffer->start = *copy_til + 1;
+	if (buffer->start > buffer->end)
+		buffer->start = NULL;
+	free(*line);
+	*line = new;
+	return (1);
+}
+
+static char	*ft_read_line(int fd, t_buffer *buffer, char **line)
+{
+	char	*copy_til;
+	size_t	line_length;
+	ssize_t	bytes_read;
+
+	line_length = 0;
+	while (!find_eol(buffer, &copy_til))
+	{
+		if (!line_aggregation(buffer, &copy_til, line, &line_length))
+			return (NULL);
+		bytes_read = read(fd, buffer->buffer, BUFFER_SIZE);
+		if (bytes_read == -1)
+			return (buffer->start = NULL, free(*line), NULL);
+		buffer->start = buffer->buffer;
+		buffer->end = buffer->start + bytes_read - 1;
+		if (buffer->end < buffer->start)
+			buffer->start = NULL;
+		if (bytes_read < BUFFER_SIZE)
+			break ;
+	}
+	find_eol(buffer, &copy_til);
+	if (!line_aggregation(buffer, &copy_til, line, &line_length))
+		return (NULL);
+	return (*line);
+}
+
+char	*get_next_line(int fd)
+{
+	static t_buffer	buffer = {{0}, NULL, NULL};
+	char			*line;
+
+	if (fd < 0 || fd >= FD_MAX || BUFFER_SIZE <= 0)
+		return (NULL);
+	line = NULL;
+	return (ft_read_line(fd, &buffer, &line));
+}
+/**
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+
+int	main(void)
+{
+	int		fd;
+	char	*line;
+
+	fd = open("../TestGNL/giant_line_nl.txt", O_RDONLY);
+	line = "";
+	while (line != NULL)
+	{
+		printf("%s", line);
+		line = get_next_line(fd);
+	}
+	line = get_next_line(fd);
+	printf("%s", line);
+	line = get_next_line(fd);
+	printf("%s", line);
+	close(fd);
+	return (0);
+}**/