Libft: The Custom C Library

💡 Project Overview

The Libft project is a fundamental exercise at 42 School designed to familiarize students with the C programming language and its standard library (<string.h>, <stdlib.h>, etc.). The goal is to reimplement a wide array of commonly used C functions, build a static library (libft.a), and ensure all functions adhere to the strict 42 Norminette style guide. /* By: afomin afomin@student.42kl.edu.my #+# +:+ #+# */ This library serves as the groundwork for all subsequent C projects within the curriculum.

⚙️ Compilation and Installation

The library is compiled using a standard Makefile.

Clone the repository:

git clone https://github.com/AlexHysel/42-Libft.git
cd 42-Libft

Compile the library:

make

This command compiles all .c source files and creates the static library file: libft.a.

Cleanup (Optional):

make clean   // Removes object files (.o)
make fclean  // Removes object files AND the libft.a file
make re      // Cleans and recompiles the entire library

📚 Library Contents

The functions in this library are organized into three main categories:

Part 1: Standard Library Recreations (Mandatory)

These functions mirror those found in the standard C library (libc).

Memory

ft_memset, ft_bzero, ft_memcpy, ft_memmove, ft_memchr, ft_memcmp

String

ft_strlen, ft_strlcpy, ft_strlcat, ft_strchr, ft_strrchr, ft_strncmp, ft_strnstr, ft_strdup, ft_atoi

Character

ft_isalpha, ft_isdigit, ft_isalnum, ft_isascii, ft_isprint, ft_toupper, ft_tolower

Part 2: Additional Utility Functions

These functions provide necessary utilities for string and memory manipulation, dynamic allocation, and file descriptor output.

ft_substr (Returns a newly allocated substring from a given string)

ft_strjoin (Concatenates two strings into a new, dynamically allocated string)

ft_strtrim (Trims leading and trailing characters specified in a set from a string)

ft_split (Splits a string by a given delimiter character, returning an array of strings)

ft_itoa (Converts an integer value to its string representation)

ft_strmapi (Applies a function to each character of a string, creating a new string)

ft_striteri (Applies a function to each character of a string, passing its index)

ft_putchar_fd (Writes a character to the given file descriptor)

ft_putstr_fd (Writes a string to the given file descriptor)

ft_putendl_fd (Writes a string to the given file descriptor, followed by a newline)

ft_putnbr_fd (Writes an integer to the given file descriptor)

Bonus Part: Singly Linked Lists

This section implements a set of functions for managing a generic singly linked list structure.

Linked List Structure (t_list)

typedef struct s_list
{
    void            *content; // Pointer to the data stored in the node
    struct s_list   *next;    // Pointer to the next node in the list
} t_list;

Linked List Functions

ft_lstnew

Creates a new list node.

ft_lstadd_front

Adds a node to the beginning of the list.

ft_lstsize

Counts the number of elements in the list.

ft_lstlast

Returns the last node of the list.

ft_lstadd_back

Adds a node to the end of the list.

ft_lstdelone

Takes a node and frees the memory allocated by the node's content and the node itself.

ft_lstclear

Deletes and frees every node from a list.

ft_lstiter

Applies a function to the content of every node.

ft_lstmap Applies a function to every node's content and creates a new list from the results.