📄 get_next_line – 42 Project

get_next_line is a project from the École 42 common core.
The goal is to implement a function that reads and returns one line at a time from a file descriptor, handling memory, buffers, and edge cases like a pro. 🧠

---

🧩 Project Objectives

• Master file I/O in C (read, open, close)
• Handle buffers, memory allocation, and string manipulation
• Build a function that returns a line with each call, including:
  • Lines with/without \n
  • Empty lines
  • Very long lines
• Manage multiple file descriptors at once

---

🔧 Function Prototype

char *get_next_line(int fd);

Reads from the file descriptor fd and returns the next line each time it’s called.
Returns NULL when there’s nothing left to read or an error occurs.

---

📁 Project Files

get_next_line/
├── get_next_line.c         # Core logic
├── get_next_line_utils.c   # String manipulation helpers
├── get_next_line.h         # Function prototypes and macros
├── main.c                  # Optional test file
├── Makefile                # Build system

---

🧪 How to Use

✅ Compile:

make

🚀 Test:

#include "get_next_line.h"

int fd = open("file.txt", O_RDONLY);
char *line;

while ((line = get_next_line(fd)) != NULL)
{
    printf("%s", line);
    free(line);
}
close(fd);

---

⚙️ BUFFER_SIZE

You can define BUFFER_SIZE at compile time:

gcc -D BUFFER_SIZE=42 get_next_line.c get_next_line_utils.c main.c

Or inside get_next_line.h:

#ifndef BUFFER_SIZE
# define BUFFER_SIZE 42
#endif

---

📚 Resources

• man 2 read
• man 3 malloc
• [42 Subject PDF / Peer feedback]

---

👤 Author

42 Login: hsilverb
Contact: LinkedIn

---

📝 License

This project was developed as part of the 42 School curriculum.
For educational and personal use only.