get_next_line (short)

Get Next Line is a small C implementation of get_next_line to read lines from a file descriptor. It is designed for simple file I/O tasks and learning C buffer-handling and line parsing.

Features

• Read a line from a file descriptor
• Minimal dependencies — plain C
• Example usage and simple tests included

Quick start

# build (example)
gcc -Wall -Wextra -Werror -o gnl get_next_line.c main.c
./gnl example.txt

Build

make fclean all

Or compile manually:

gcc -D BUFFER_SIZE=32 -Wall -Wextra -Werror -I. get_next_line.c get_next_line_utils.c -o gnl

Usage

int fd = open("file.txt", O_RDONLY);
char *line;
while ((line = get_next_line(fd)) != NULL)
{
    printf("%s", line);
    free(line);
}
close(fd);

Returns a malloc'd string (includes \n if present). Caller must free.

API

• char *get_next_line(int fd); — returns next line or NULL on EOF/error.

Notes

• Uses a static leftover buffer to keep unread data between calls.
• Avoid repeated concatenation of a growing string inside the read loop — that caus es O(n^2) behavior and timeouts on very large single-line files with small BUFFER_SIZE.
• For large single-line files prefer an approach that minimizes realloc/copy (chunked buffers, doubling growth, or assemble final line once).

Testing

Use your usual francinette/getcheck setup:

getcheck francinette --strict

License

This project is available under the MIT License. See LICENSE for details.

License: educational / adapt freely.