Your very first own library

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⚠️ Disclaimer

• Full Portfolio: This repository focuses on this specific project. You can find my entire 42 curriculum 👉 here.
• Subject Rules: I strictly follow the rules regarding 42 subjects; I cannot share the PDFs, but I explain the concepts in this README.
• Archive State: The code is preserved exactly as it was during evaluation (graded state). I do not update it, so you can see my progress and mistakes from that time.
• Academic Integrity: I encourage you to try the project yourself first. Use this repo only as a reference, not for copy-pasting. Be patient, you will succeed.

📂 Purpose

Libft is the cornerstone of the 42 curriculum. Its goal is to build a custom C library that will be used in almost every future project.

Since we are not allowed to use most standard C libraries (like <string.h> or <stdlib.h>) in our exercises, we must rewrite these functions from scratch. We will learn how to create a Makefile to automate compilation and generate a static library (libft.a). Also, organizing code efficiently using header files (.h) to declare prototypes and structures.

⚠️ Evolution & Reliability: This library is designed to grow. In the future, you will add more functions, either required by other projects or for your own utility. Therefore, your code must be rock-solid: no memory leaks, no segmentation faults, and correct return values. Treat this project as the most important asset in your curriculum.

🐨 Status

Completed on 27/10/2025 with bonus.

  

🔷 Usage

First, clone this repository.

https://github.com/Overtekk/Libft.git

Compile with make...

make

...and add bonus functions

make bonus

You can use my main to test all functions. You can run it using

cc -Wall -Werror -Wextra main/main.c libft.a && ./a.out

Enter the number of the function you want to test (ex: 1 for ft_isalpha), then follow the instructions.

A main without bonus dependencies is also available. Use this instead:

cc -Wall -Werror -Wextra main/main_no_bonus.c libft.a && ./a.out

Warning

The compilation will fail if some functions are missing from your library.

🖱️ Function list

🧱 Memory

Function	Function
ft_memset	ft_memchr
ft_bzero	ft_memcmp
ft_memcpy	ft_calloc
ft_memmove	ft_strdup

🔡 String Manipulation

Function	Function	Function
ft_strlen	ft_strncmp	ft_split
ft_strlcpy	ft_strnstr	ft_strmapi
ft_strlcat	ft_substr	ft_striteri
ft_strchr	ft_strjoin
ft_strrchr	ft_strtrim

🔢 Converters & Checkers

Function	Function
ft_isalpha	ft_toupper
ft_isdigit	ft_tolower
ft_isalnum	ft_atoi
ft_isascii	ft_itoa
ft_isprint

📠 File Descriptor

Function
ft_putchar_fd
ft_putstr_fd
ft_putendl_fd
ft_putnbr_fd

⛓️ Linked List (Bonus)

Function	Function
ft_lstnew	ft_lstdelone
ft_lstadd_front	ft_lstclear
ft_lstsize	ft_lstiter
ft_lstlast	ft_lstmap
ft_lstadd_back

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