🇫🇷 Version française disponible ici

---

Project presentation - libft

Description

This project involves creating a reusable personal static library (libft.a) by reimplementing useful standard C library functions, along with additional functions that will be helpful in future projects.

The purpose is to gain a deeper understanding of data structures and basic algorithms. At 42, we are often restricted from using certain standard libraries, so we build and expand our own library as we progress through the curriculum.

For example:

• ft_printf (with its own Makefile), a 42 project added to the library, see more here.
• get_next_line, a 42 project integrated into libft, see more here.

---

Languages & Technologies

Language

• C (C99 standard)

Technologies

• Makefile
• Static library (.a)
• Dynamic memory allocation
• Memory manipulation
• String manipulation
• Linked lists

---

What’s included in the library

The project instructions divide it into three sections:

1. Libc Functions - Reimplementations of some standard C functions.
2. Additional Functions - Extra utility functions considered useful for later projects.
3. Linked List Functions - Functions used to manipulate linked lists.
4. Personal Functions - Additional functions I implemented on my own.

Libc Functions	Description
ft_isalnum	Checks if a char is alphanumeric
ft_isalpha	Checks if a char is an alphabetic letter
ft_isascii	Checks if a char belongs to the ASCII set
ft_isdigit	Checks if a char is a digit (0-9)
ft_isprint	Checks if a char is printable
ft_tolower	Converts an uppercase letter to lowercase
ft_toupper	Converts a lowercase letter to uppercase
ft_bzero	Sets a block of memory to zero
ft_calloc	Allocates memory and initializes it to zero
ft_strncmp	Compares two strings up to a given number of characters
ft_strnstr	Locates a substring within a string, limited by length
ft_memchr	Searches for a byte in a memory block
ft_memcmp	Compares two memory blocks
ft_memcpy	Copies memory from source to destination
ft_memmove	Copies memory safely, handling overlapping regions
ft_memset	Fills a memory block with a constant byte
ft_atoi	Converts a string to an integer
ft_strlcat	Concatenates strings with size limitation
ft_strlcpy	Copies a string with size limitation
ft_strlen	Returns the length of a string
ft_strrchr	Finds the last occurrence of a character in a string
ft_strchr	Finds the first occurrence of a character in a string
ft_strdup	Duplicates a string into newly allocated memory

Additional Functions	Description
ft_substr.c	Extracts a substring from a string
ft_strjoin	Concatenates two strings into a new one
ft_strtrim	Trims specified characters from the beginning and end of a string
ft_split	Splits a string into an array using a char as a delimiter
ft_itoa	Converts an integer to a string
ft_strmapi	Creates a new string by applying a function to each character of a string
ft_striteri	Applies a function to each character of a string, modifying it in place
ft_putchar_fd	Writes a char 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 an integer to a file descriptor

Linked list Functions	Description
ft_lstadd_back	Adds a new element at the end of a linked list
ft_lstadd_front	Adds a new element at the beginning of a linked list
ft_lstclear	Deletes and frees all elements of a linked list
ft_lstdelone	Deletes and frees a single list element
ft_lstiter	Applies a function to each element of a list
ft_lstlast	Returns the last element of a linked list
ft_lstmap	Creates a new list by applying a function to each element
ft_lstnew	Creates a new linked list element
ft_lstsize	Returns the number of elements in a linked list

Personal Functions	Description
ft_printf	Custom implementation of the printf function supporting the following format specifiers: c, s, p, d, i, u, x, X and %
get_next_line	Reads a file descriptor line by line
countwords	Returns the number of words in a string separated by a given delimiter.
strjoin_wfree	Concatenates two strings into a new one and frees the first string
factorial	Computes the factorial of a number recursively
fibonacci	Returns the Fibonacci number at a given index
find_next_prime	Finds the smallest prime number greater than or equal to the given number
int_overflow_check	Checks if the string represents a valid integer
nb_is_prime	Checks whether a number is a prime number
nb_sqrt	Returns the integer square root of a number if it exists.
power_nb	Computes a number raised to a given power recursively
ft_is_white_space	Checks if a char is a space, tab or newline

---

Using libft

Makefile rules

1. all as default rule: builds the project, compiles all .c files into .o, then creates the library (.a)
2. clean : removes compiled object files (.o)
3. fclean : clean rule and removes the library (.a)
4. re : fclean then all rule

---

How to use libft

1. Clone libft into your project folder first : git clone https://github.com/bibickette/libft
2. Build libft using its Makefile : run make -s -C libft, this runs the Makefile in the libft folder.
3. Include the libft.h header in your project to access the functions.
4. Compile your project with the libft library: cc your_files.o -L./libft -lft -o your_program

Now your project can use libft functions !

---

Project validation date : December 23, 2023