📚 Libft

📝 Introduction

Libft is the first project at 42 School, focusing on recreating various standard C library functions, as well as additional utility functions that will be used throughout the entire curriculum.

"By rewriting these functions, you'll gain a deeper understanding of their inner workings and become more proficient in C programming."

The purpose is to build your own library, which you'll expand and use in your future C projects at 42.

🎯 Project Objectives

• Reimplement standard C library functions with identical behaviors
• Create additional utility functions not found in the standard library
• Learn to create and manage a library in C
• Deepen understanding of memory management, strings, and data structures in C
• Apply rigorous error handling and edge case management

🛠️ Implemented Functions

Part 1: Libc Functions

Reimplementation of standard C library functions

Function	Description
ft_isalpha	Check if character is alphabetic
ft_isdigit	Check if character is a digit
ft_isalnum	Check if character is alphanumeric
ft_isascii	Check if character is in ASCII table
ft_isprint	Check if character is printable
ft_strlen	Calculate string length
ft_memset	Fill memory with a constant byte
ft_bzero	Zero a byte string
ft_memcpy	Copy memory area
ft_memmove	Copy memory area with overlap handling
ft_strlcpy	Size-bounded string copying
ft_strlcat	Size-bounded string concatenation
ft_toupper	Convert character to uppercase
ft_tolower	Convert character to lowercase
ft_strchr	Locate character in string (first occurrence)
ft_strrchr	Locate character in string (last occurrence)
ft_strncmp	Compare two strings (size-bounded)
ft_memchr	Scan memory for a character
ft_memcmp	Compare memory areas
ft_strnstr	Locate a substring in a string (size-bounded)
ft_atoi	Convert ASCII string to integer
ft_calloc	Allocate and zero-initialize array
ft_strdup	Create a duplicate of the string

Part 2: Additional Functions

Functions that are either not in the libc, or that are part of it but in a different form

Function	Description
ft_substr	Extract substring from string
ft_strjoin	Concatenate two strings
ft_strtrim	Trim beginning and end of string with specific set of chars
ft_split	Split string using a character as delimiter
ft_itoa	Convert integer to ASCII string
ft_strmapi	Apply function to each character of a string with index
ft_striteri	Apply function to each character of a string with index
ft_putchar_fd	Output a character to a file descriptor
ft_putstr_fd	Output a string to a file descriptor
ft_putendl_fd	Output a string to a file descriptor, followed by a newline
ft_putnbr_fd	Output a number to a file descriptor

Bonus Part

Functions to manipulate linked lists

Function	Description
ft_lstnew	Create a new list element
ft_lstadd_front	Add new element at beginning of list
ft_lstsize	Count elements in a list
ft_lstlast	Return the last element of the list
ft_lstadd_back	Add new element at end of list
ft_lstdelone	Delete element from list using a delete function on content
ft_lstclear	Delete sequence of elements from list
ft_lstiter	Apply function to content of all list's elements
ft_lstmap	Apply function to content of all list's elements and create new list

🧪 Testing

The library was extensively tested using:

• 42 School's Moulinette
• Unit tests with libft-unit-test
• War Machine
• Custom test cases for edge conditions

📋 Skills Developed

• Deep understanding of C memory management
• String manipulation techniques
• Implementation of data structures (linked lists)
• Rigorous function testing and edge case handling
• Makefile creation and usage
• Library creation and management

---

📊 Project Stats

Metric	Value
Final Score	125/100
Functions Implemented	43
Lines of Code	~1500
Completion Time	2 weeks