My Handmade C Libraries

A collection of foundational C libraries built from scratch to deepen understanding of memory management, strings, and low-level programming.

About

This repository contains three base libraries I built for future C projects at 42 and beyond:

libft

A custom reimplementation of the C standard library — built from scratch to fully understand memory, pointers, and core functions.

• Reimplements standard C library functions (strlen, memcpy, atoi, etc.)
• Includes a bonus part with linked list utilities (t_list)
• Used as a base library for all following C projects
• Continuously reinforced and improved through each new project

get_next_line

Line-by-line file reader in C A low-level implementation of a function that reads files line by line, managing buffers and memory efficiently.

• Handles newline placements, buffer overflows, and EOF correctly
• Supports multiple file descriptors via the bonus version
• Helps master buffer logic, memory allocation, and static variables

ft_printf

Custom implementation of printf() A functional recreation of the standard printf() function, using only basic write() calls.

• Supports format specifiers: %c, %s, %p, %d, %i, %u, %x, %X, %%
• Built to understand variadic functions and formatted output
• Used across other projects for formatted logging and debugging

Usage

1. Clone the repository

git clone https://github.com/Yuxin29/Mini_C_Library.git
cd Mini_C_Library

2. Compilation Run the following in each library’s directory:

$ make          # Compile all mandatory functions
$ make bonus    # Compile extra bonus functions
$ make clean    # Remove object files
$ make fclean   # Remove object files and static library
$ make re       # Recompile everything from scratch

3. Include in Your Project

#include "libft.h"
and compile with:
gcc your_file.c -L. -lft

Testing

I used multiple online testers to test my libft. These testers has different emphasises, covering different edge cases. There are cases where my libft does not pass all tests, but I have reasoned it and compromised for a balanced solution. Testers that I used include: Tripouille/LibftTester