Libft  

This project has been created as part of the 42 curriculum by lbraga.

Libft is the first project in the 42 curriculum. The goal is to create the libft.a static library by reimplementing some functions from the standard C library and a few additional utility functions. This project focuses on understanding how these functions work under the hood, handling memory management, string manipulation, and linked lists in the bonus part.

1. Libft Functions
2. Instructions
3. Resources
4. AI Disclosure
5. Final Notes
6. Function List

Libft Functions

• Characters: isalpha isdigit isalnum isascii isprint toupper tolower
• Memory: memset bzero memcpy memmove memchr memcmp calloc
• Strings: strlen strlcpy strlcat strncmp strchr strrchr strnstr strdup substr strjoin strtrim split strmapi striteri
• Conversion: atoi itoa
• File Descriptor: putchar_fd putstr_fd putendl_fd putnbr_fd
• Linked Lists (bonus): lstnew lstadd_front lstsize lstlast lstadd_back lstdelone lstclear lstiter lstmap
• List Struct:

   typedef struct s_list
   {
   	void			*content;
   	struct s_list	*next;
   }					t_list;
  

Instructions

To compile the library, you must have the cc compiler and the make tool installed.

1. Clone the repository:

   git clone https://github.com/leandrobbj/libft.git && cd libft
   

2. Create the library:

   make
   

Other commands:

• make bonus: Creates the library including the bonus functions.
• make clean: Removes the object files (.o).
• make fclean: Removes the object files and the compiled library (libft.a).
• make re: Performs a fclean followed by a make.

Resources

• CS50: Introduction to Computer Science - Harvard University's lectures on C programming, memory management, and algorithms.
• Linux Programmer's Manual (man pages) - Useful for understanding the behavior of libc functions.
• Norminette Documentation - Helpful for ensuring the code follows the school's coding standards.

AI Disclosure

In compliance with the 42 curriculum requirements, I used AI tools, including the CS50.ai Duck, during the development of this project to support my learning. These tools were used to research and summarize technical articles about memory management, pointer arithmetic, recursion, and data structure iteration.

The AI also helped with test development to identify potential logic bugs and edge cases during the implementation of complex functions, and supported the organization and formatting of project configuration files.

Final Notes

Developing Libft was a significant challenge that helped me understand the standard functions from scratch. This project gave me a foundation in pointer arithmetic for direct memory manipulation and in working with pointers to pointers. Ultimately, it was about building the skills needed to solve problems and create a reliable toolkit for future projects.

This is the end of the documentation. For a quick reference on how each function behaves, please refer to the List below.

Function List

Libc Functions	Description
isalpha	Checks for an alphabetic character.
isdigit	Checks for a digit (0 through 9).
isalnum	Checks for an alphanumeric character.
isascii	Checks whether c fits into the ASCII character set.
isprint	Checks for any printable character.
strlen	Calculates the length of a string.
memset	Fills memory with a constant byte.
bzero	Erases the data in n bytes of memory.
memcpy	Copies memory area.
memmove	Copies memory area (handles overlapping).
strlcpy	Size-bounded string copying.
strlcat	Size-bounded string concatenation.
toupper	Converts a lowercase letter to uppercase.
tolower	Converts an uppercase letter to lowercase.
strchr	Locates a character in a string.
strrchr	Locates a character in a string, searching from the end.
strncmp	Compares two strings up to n characters.
memchr	Scans memory for a character.
memcmp	Compares memory areas.
strnstr	Locates a substring in a string, searching up to n characters.
atoi	Converts a string to an integer.
calloc	Allocates memory and initializes it to zero.
strdup	Creates a duplicate of a string using malloc.

Additional Functions	Description
substr	Returns a substring from a string.
strjoin	Concatenates two strings into a new one.
strtrim	Trims specific characters from the start and end of a string.
split	Splits a string into an array of strings using a delimiter.
itoa	Converts an integer to a string.
strmapi	Applies a function to each character of a string to create a new one.
striteri	Applies a function to each character of a string by its index.
putchar_fd	Outputs a character to a specific file descriptor.
putstr_fd	Outputs a string to a specific file descriptor.
putendl_fd	Outputs a string followed by a newline to a file descriptor.
putnbr_fd	Outputs an integer to a specific file descriptor.

Linked Lists Bonus Functions	Description
lstnew	Creates a new list element.
lstadd_front	Adds an element to the beginning of a list.
lstsize	Counts the number of elements in a list.
lstlast	Returns the last element of a list.
lstadd_back	Adds an element to the end of a list.
lstdelone	Deletes one element from a list using a given function.
lstclear	Deletes and frees an entire list.
lstiter	Iterates through a list and applies a function to each element.
lstmap	Iterates through a list and applies a function to create a new list.