From 94b47301589acbc1ac7e75dd93b183a796cc9bad Mon Sep 17 00:00:00 2001
From: Dominik Kaiser <dkaiser@1-C-5.42heilbronn.de>
Date: Thu, 21 Mar 2024 13:18:23 +0100
Subject: [PATCH] Add core functionality

---
 get_next_line.c | 146 +++++++++++++++++++++++++++++++++++++++++++++++-
 get_next_line.h |   7 ++-
 2 files changed, 150 insertions(+), 3 deletions(-)

diff --git a/get_next_line.c b/get_next_line.c
index d7bd0b2..de2bcce 100644
--- a/get_next_line.c
+++ b/get_next_line.c
@@ -6,13 +6,155 @@
 /*   By: dkaiser <dkaiser@student.42heilbronn.de    +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2024/03/15 14:13:51 by dkaiser           #+#    #+#             */
-/*   Updated: 2024/03/15 15:00:41 by dkaiser          ###   ########.fr       */
+/*   Updated: 2024/03/21 13:16:45 by dkaiser          ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
 #include "get_next_line.h"
 
+int	ft_strlen(const char *str)
+{
+	int	len;
+
+	len = 0;
+	while (str[len])
+		len++;
+	return (len);
+}
+
+static int	copy_str(char *dst, const char *src)
+{
+	int	i;
+
+	i = 0;
+	while (src[i])
+	{
+		dst[i] = src[i];
+		i++;
+	}
+	return (i);
+}
+
+char	*ft_strjoin(char const *s1, char const *s2)
+{
+	int		len;
+	char	*result;
+
+	len = ft_strlen(s1) + ft_strlen(s2);
+	result = malloc(len + 1);
+	if (result)
+	{
+		result[len] = '\0';
+		len = copy_str(result, s1);
+		len = copy_str(result + len, s2);
+		return (result);
+	}
+	else
+		return (0);
+}
+
+int	get_next_line_len(char *buffer)
+{
+	int	len;
+
+	len = 0;
+	while (len < BUFFER_SIZE)
+	{
+		if (!buffer[len])
+			return (len);
+		if (buffer[len] == '\n')
+			return (len + 1);
+		len++;
+	}
+	return (-1);
+}
+
+char	*get_next_line_rec(int fd, char *buffer, char *result)
+{
+	int	len;
+	int	start;
+	int	i;
+    int  read_len;
+	char *old_result;
+
+    read_len = -2;
+	if (!buffer[0])
+		read_len = read(fd, buffer, BUFFER_SIZE);
+	len = get_next_line_len(buffer);
+	if (!len)
+		return (result);
+	if (len == -1)
+	{
+		if (!result)
+		{
+			result = malloc(BUFFER_SIZE);
+			start = 0;
+		}
+		else
+		{
+			start = ft_strlen(result);
+			old_result = result;
+			result = ft_strjoin(result, malloc(BUFFER_SIZE));
+			free(old_result);
+		}
+        if (!result)
+            return NULL;
+        i = 0;
+        while (i < BUFFER_SIZE)
+        {
+            result[start + i] = buffer[i];
+            i++;
+        }
+        i = 0;
+        while (i < BUFFER_SIZE)
+            buffer[i++] = 0;
+        result = get_next_line_rec(fd, buffer, result);
+		return (result);
+	}
+	else
+	{
+		if (!result)
+		{
+			result = malloc(len);
+			start = 0;
+		}
+		else
+		{
+			start = ft_strlen(result);
+			old_result = result;
+			result = ft_strjoin(result, malloc(len));
+			free(old_result);
+		}
+		if (!result)
+			return (NULL);
+		i = 0;
+		while (i < len)
+		{
+			result[start + i] = buffer[i];
+			i++;
+		}
+		i = 0;
+		while (len < BUFFER_SIZE)
+		{
+			buffer[i] = buffer[len];
+			buffer[len] = 0;
+			i++;
+			len++;
+		}
+		while (i < BUFFER_SIZE)
+			buffer[i++] = 0;
+        if (read_len == -2)
+            result = get_next_line_rec(fd, buffer, result);
+		return (result);
+	}
+}
+
 char	*get_next_line(int fd)
 {
-    return NULL;
+	static char	buffer[BUFFER_SIZE];
+	char		*result;
+
+	result = NULL;
+	result = get_next_line_rec(fd, buffer, result);
+	return (result);
 }
diff --git a/get_next_line.h b/get_next_line.h
index 6c13f85..7e5c093 100644
--- a/get_next_line.h
+++ b/get_next_line.h
@@ -6,13 +6,18 @@
 /*   By: dkaiser <dkaiser@student.42heilbronn.de    +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2024/03/15 14:14:07 by dkaiser           #+#    #+#             */
-/*   Updated: 2024/03/15 14:16:32 by dkaiser          ###   ########.fr       */
+/*   Updated: 2024/03/21 11:24:39 by dkaiser          ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
 #ifndef GET_NEXT_LINE_H
 # define GET_NEXT_LINE_H
 # include <stdlib.h>
+# include <unistd.h>
+
+# ifndef BUFFER_SIZE
+#  define BUFFER_SIZE 42
+# endif
 
 char	*get_next_line(int fd);
 #endif // GET_NEXT_LINE_H
-- 
2.47.2