This project has been created as part of the 42 curriculum by csekakul.

Description

libft is a custom C library that reimplements a set of standard libc functions, along with additional utility functions. The goal of this project is to deepen the understanding of:

• memory management
• string manipulation
• linked lists
• low-level C programming

All functions are written from scratch in C and compiled into a static library (libft.a). The behavior of the reimplemented functions follows the corresponding libc functions as described in their manual pages. This library is intended to be reused in future 42 projects.

Implemented Functions

The library includes functions from the following categories:

Character checks:

• ft_isalpha
• ft_isdigit
• ft_isalnum
• ft_isascii
• ft_isprint

String manipulation:

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

Memory manipulation:

• ft_memset
• ft_bzero
• ft_memcpy
• ft_memmove
• ft_memchr
• ft_memcmp
• ft_calloc

Conversion:

• ft_atoi
• ft_itoa

File descriptor output:

• ft_putchar_fd
• ft_putstr_fd
• ft_putendl_fd
• ft_putnbr_fd

Linked list utilities:

• ft_lstnew
• ft_lstadd_front
• ft_lstsize
• ft_lstlast
• ft_lstadd_back
• ft_lstdelone
• ft_lstclear
• ft_lstiter
• ft_lstmap

These functions provide a reusable foundation for string handling, memory operations, numeric conversions, file descriptor output, and basic linked list manipulation.

Instructions

Compile the library make

This will generate the file libft.a

Clean object files make clean

Clean everything make fclean

Recompile from scratch make re

Include the header in your project #include "libft.h"

Compile with your program cc main.c -L. -lft

Resources

• man libc
• man strlen, man memcpy, man atoi, etc.
• 42 intra documentation
• AI usage:
  • AI tools were used as a learning aid to better understand certain concepts such as:
    • file descriptors
    • linked lists
    • general behavior of some standard libc functions
  • AI was not used to generate final code for the project

All implementations were written manually in accordance with the 42 subject rules and official documentation.