This is my submission for the Libft project at School 42. The goal of this project was to create our own library of useful C functions, as a way to improve our programming skills and become more familiar with the standard C library.

The library contains a total of 43 functions, divided into four categories:

These functions allow for character identification:

• ft_isalpha: checks if a character is alphabetical.
• ft_isdigit: checks if a character is a digit.
• ft_isalnum: checks if a character is alphanumeric.
• ft_isascii: checks if a character is ASCII.
• ft_isprint: checks if a character is printable.
• ft_toupper: converts a character to uppercase.
• ft_tolower: converts a character to lowercase.

These functions allow for memory manipulation:

• ft_memset: fills a block of memory with a specified value.
• ft_bzero: sets a block of memory to zero.
• ft_memcpy: copies a block of memory from source to destination.
• ft_memmove: copies a block of memory from source to destination, even if they overlap.
• ft_memchr: searches a block of memory for a specified character.
• ft_memcmp: compares two blocks of memory.
• ft_calloc: allocates memory for an array of elements and initializes it to zero.

These functions allow for string manipulation:

• ft_strlen: calculates the length of a string.
• ft_strlcpy: copies a string up to a specified size.
• ft_strlcat: appends a string to another string, up to a specified size.
• ft_strchr: finds the first occurrence of a specified character in a string.
• ft_strrchr: finds the last occurrence of a specified character in a string.
• ft_strnstr: finds a substring in a string, up to a specified length.
• ft_strncmp: compares two strings up to a specified length.
• ft_strdup: duplicates a string.
• ft_substr: extracts a substring from a string.
• ft_strjoin: concatenates two strings.
• ft_strtrim: trims whitespace characters from the beginning and end of a string.
• ft_split: splits a string into substrings based on a delimiter character.
• ft_itoa: converts an integer to a string.
• ft_atoi: converts a string to an integer.
• ft_strmapi: applies a function to each character in a string.
• ft_striteri: applies a function to each character of a string.

These functions allow for character manipulation:

• ft_putchar_fd: outputs a character to a file descriptor.
• ft_putstr_fd: outputs a string to a file descriptor.
• ft_putendl_fd: outputs a string to a file descriptor, followed by a newline character.
• ft_putnbr_fd: outputs an integer to a file descriptor.

These functions are not part of the required set, but are included as bonus functions:

• ft_lstnew: creates a new linked list node.
• ft_lstadd_front: adds a node to the beginning of a linked list.
• ft_lstsize: calculates the size of a linked list.
• ft_lstlast: returns the last node of a linked list.
• ft_lstadd_back: adds a node to the end of a linked list.
• ft_lstdelone: deletes a node from a linked list.
• ft_lstclear: deletes all nodes from a linked list.
• ft_lstiter: applies a function to each node in a linked list.
• ft_lstmap: applies a function to each node in a linked list, creating a new list with the results.

To use the library, simply include the header file libft.h in your C program, and link with the libft.a static library.

Overall, this project was a great way to learn more about the standard C library, and to become more comfortable with programming in C. Project was validated at 125/100.