📚 Libft — My Very First C Library

Libft is the first project at 1337 School that consists of re-coding a set of standard C library functions, along with additional utility functions that will be reused throughout future projects.

Quick Overview

• Built with: C
• Focus: Rebuilding core C standard library functions and utility functions from scratch.
• What I learned: Pointers, strings, memory manipulation, linked lists, clean function design, and low-level debugging.

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A foundation library built from scratch to understand memory, pointers, and data structures in C.

Overview

The goal of Libft is to understand, implement, and master the core mechanisms of C programming:

• Memory management (malloc, free, pointer arithmetic)
• String manipulation
• Linked lists
• Static functions and modular organization
• Compilation via Makefile

You end up with your own library, libft.a, that can be linked to any future C project.

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Compilation

Clone the repository and run:

make          # builds mandatory part
make bonus    # builds with bonus (linked list functions)
make clean    # removes object files
make fclean   # removes objects and libft.a
make re       # rebuild everything`

Project Structure

libft/
├── Makefile
├── libft.h
├── ft_*.c
└── (bonus) ft_lst*.c

🧩 Implemented Functions

Part 1 — Libc Functions

Category	Functions
Character checks	ft_isalpha ft_isdigit ft_isalnum ft_isascii ft_isprint
String length / memory	ft_strlen ft_memset ft_bzero ft_memcpy ft_memmove
String search / compare	ft_strlcpy ft_strlcat ft_strchr ft_strrchr ft_strncmp ft_memchr ft_memcmp ft_strnstr
Conversion	ft_atoi
Memory allocation	ft_calloc ft_strdup
Character case	ft_toupper ft_tolower

Part 2 — Additional Functions

Category	Functions
String manipulation	ft_substr ft_strjoin ft_strtrim ft_split
Conversion	ft_itoa
Function pointers	ft_strmapi ft_striteri
File descriptors (output)	ft_putchar_fd ft_putstr_fd ft_putendl_fd ft_putnbr_fd

Bonus — Linked Lists

Function	Description
ft_lstnew	Create a new node
ft_lstadd_front	Add a node at the beginning of the list
ft_lstsize	Count the number of nodes
ft_lstlast	Return the last node of the list
ft_lstadd_back	Add a node at the end of the list
ft_lstdelone	Delete one node using a function del
ft_lstclear	Delete and free all nodes
ft_lstiter	Apply a function to each node’s content
ft_lstmap	Create a new list resulting from the successive applications of a function

🚀 Usage Example

After building the library, you can use it in any C project:

make
cc main.c libft.a -o my_program
./my_program

✅ Project Status

Check	Result
Norminette	✅ Passed
Memory leaks	✅ None (checked with Valgrind)
Mandatory part	✅ Completed
Bonus part	✅ Completed
Segfaults	🚫 None
Compilation flags	-Wall -Wextra -Werror

Author

Walid Krati [wkrati]

AKA: Kratos

🎓 1337 / 42 Network

GitHub — @wkratos77