Libft is one of the initial projects at 42 School, designed to help students create their own function library in C, replacing many standard utilities from <string.h>, <stdlib.h>, and <ctype.h>.

The purpose of Libft is to strengthen your understanding of the C language fundamentals, particularly memory manipulation, string handling, and data conversion. Throughout this project, you will implement custom versions of essential functions that will be useful in future developments.

These functions allow you to handle and modify strings:

• ft_strlen → Returns the length of a string.
• ft_strcpy, ft_strncpy → Copies a string into another.
• ft_strdup → Creates a duplicate of a string in dynamic memory.
• ft_strcat, ft_strncat → Concatenates two strings.
• ft_strchr, ft_strrchr → Searches for a character within a string.
• ft_strcmp, ft_strncmp → Compares two strings.
• ft_strstr, ft_strnstr → Finds a substring within another string.

These functions allow you to work with memory more efficiently:

• ft_memset → Fills a memory block with a given value.
• ft_bzero → Sets a memory block to zero.
• ft_memcpy, ft_memccpy → Copies data from one memory location to another.
• ft_memmove → Moves memory blocks safely.
• ft_memchr → Searches for a specific byte within a memory block.
• ft_memcmp → Compares two memory blocks.
• ft_calloc → Allocates memory and initializes it to zero.

Key functions for converting between different data types:

• ft_atoi → Converts a string into an integer.
• ft_itoa → Converts an integer into a string.
• ft_tolower, ft_toupper → Converts characters to lowercase or uppercase.

Useful functions for character classification, similar to <ctype.h>:

• ft_isalpha → Checks if a character is a letter.
• ft_isdigit → Checks if it is a number.
• ft_isalnum → Checks if it is alphanumeric.
• ft_isascii → Determines if it belongs to the ASCII range.
• ft_isprint → Checks if it is a printable character.

Extra functions to enhance data handling:

• ft_substr → Extracts a substring from a larger string.
• ft_strjoin → Merges two strings into one.
• ft_strtrim → Trims whitespace from the beginning and end of a string.
• ft_split → Splits a string into multiple substrings based on a delimiter.
• ft_strmapi → Applies a function to each character of a string and returns a new one.
• ft_putchar_fd → Writes a character to a file descriptor.
• ft_putstr_fd → Writes a string to a file descriptor.
• ft_putendl_fd → Writes a string followed by a newline to a file descriptor.
• ft_putnbr_fd → Writes a number to a file descriptor.

To compile Libft, simply clone the repository and run:

make

This will generate libft.a, a static library that you can include in your projects with:

#include "libft.h"

To clean object files and recompile, use:

make clean    # Removes intermediate files
make fclean   # Deletes intermediate files and libft.a
make re       # Cleans and recompiles everything