It seems to work!

get_next_line.c

@@ -6,7 +6,7 @@
 /*   By: kcolin <marvin@42.fr>                      +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2024/10/23 20:32:46 by kcolin            #+#    #+#             */
-/*   Updated: 2024/10/26 10:27:01 by kcolin           ###   ########.fr       */
+/*   Updated: 2024/10/31 12:45:27 by kcolin           ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -15,7 +15,7 @@
 
 char	*ft_strchr(const char *s, int c)
 {
-	int	i;
+	size_t	i;
 
 	i = 0;
 	while (s[i] != '\0')
@@ -31,7 +31,7 @@ char	*ft_strchr(const char *s, int c)
 
 size_t	ft_strlen(const char *s)
 {
-	int	i;
+	size_t	i;
 
 	i = 0;
 	while (s[i] != '\0')
@@ -85,7 +85,7 @@ size_t	ft_strlcat(char *dst, const char *src, size_t size)
 }
 
 
-char	*ft_strjoin(char const *s1, char const *s2)
+char	*ft_strjoin_free_s1(char const *s1, char const *s2)
 {
 	char	*out;
 	size_t	len;
@@ -96,13 +96,37 @@ char	*ft_strjoin(char const *s1, char const *s2)
 		return (NULL);
 	ft_strlcpy(out, s1, len);
 	ft_strlcat(out, s2, len);
+	free((void *)s1);
 	return (out);
 }
 
+char	*shorten_buffer(char *buffer)
+{
+	char	*outbuf;
+	char	*addr_of_newline;
+	size_t	index_after_newline;
+	size_t	outlen;
+
+	addr_of_newline = ft_strchr(buffer, '\n');
+	if (addr_of_newline == 0)
+	{
+		outbuf = malloc(1 * sizeof(char));
+		outbuf[0] = '\0';
+	}
+	else
+	{
+		index_after_newline = addr_of_newline + 1 - buffer;
+		outlen = ft_strlen(buffer + index_after_newline) + 1;
+		outbuf = malloc(outlen * sizeof(char));
+		ft_strlcpy(outbuf, buffer + index_after_newline, outlen);
+	}
+	free(buffer);
+	return (outbuf);
+}
 
 char	*get_next_line(int fd)
 {
-	static char	*buffer = "";
+	static char	*buffer = NULL;
 	char		*read_buffer;
 	int			num_bytes_read;
 	size_t		length;
@@ -111,6 +135,11 @@ char	*get_next_line(int fd)
 	read_buffer = malloc(BUFFER_SIZE * sizeof(char));
 	num_bytes_read = 1;
 	length = 0;
+	if (buffer == NULL)
+	{
+		buffer = malloc(sizeof(char));
+		buffer[0] = '\0';
+	}
 	while (num_bytes_read != 0)
 	{
 		// DONE: if newline found,
@@ -119,11 +148,18 @@ char	*get_next_line(int fd)
 			// DONE: copy string until newline to new buffer,
 			outbuf = malloc((ft_strchr(buffer, '\n') - buffer + 2) * sizeof(char));
 			if (outbuf == NULL)
+			{
+				free(read_buffer);
+				free(buffer);
+				buffer = NULL;
 				return (NULL);
+			}
 			ft_strlcpy(outbuf, buffer, ft_strchr(buffer, '\n') - buffer + 2);
-			// TODO: shorten current buffer,
+			// DONE: shorten current buffer,
-			buffer += ft_strchr(buffer, '\n') - buffer + 1;
+			// buffer += ft_strchr(buffer, '\n') - buffer + 1;
+			buffer = shorten_buffer(buffer);
 			// DONE: and return.
+			free(read_buffer);
 			return (outbuf);
 		}
 		num_bytes_read = read(fd, read_buffer + length, BUFFER_SIZE - length - 1);
@@ -138,8 +174,13 @@ char	*get_next_line(int fd)
 		length += num_bytes_read;
 		// DONE: join with big buffer
 		// FIXME: correctly free buffer
-		buffer = ft_strjoin(buffer, read_buffer);
+		buffer = ft_strjoin_free_s1(buffer, read_buffer);
 	}
 	free(read_buffer);
+	if (ft_strlen(buffer) == 0)
+	{
+			free(buffer);
+			buffer = NULL;
+	}
 	return (buffer);
 }

test.c

@@ -17,18 +17,21 @@
 int	main(int argc, char **argv)
 {
 	int		fd;
+	int		i;
 	char	*line;
 
 	if (argc == 2)
 	{
 		fd = open(argv[1], O_RDONLY);
 		line = "";
+		i = 0;
 		while (line != NULL)
 		{
 			line = get_next_line(fd);
 			if (line != NULL)
 			{
-				printf("%s", line);
+				i++;
+				printf("%d\t%s", i, line);
 				free(line);
 			}
 		}