This project has been created as part of the 42 curriculum by yoben-ch.

Libft

Description

Libft is a custom C static library created for the 42 curriculum. Its goal is to reimplement a selection of standard C library functions, add useful string and memory utilities, and provide a small linked-list API that can be reused in later C projects.

The project builds a static archive named libft.a. All source files are written in C, follow the 42 Norm, and are compiled with cc using -Wall -Wextra -Werror.

Library Details

This library contains three groups of functions.

Libc Reimplementations

These functions reproduce the behavior of their standard C library equivalents, using the ft_ prefix:

• Character checks and conversion: ft_isalpha, ft_isdigit, ft_isalnum, ft_isascii, ft_isprint, ft_toupper, ft_tolower
• Memory functions: ft_memset, ft_bzero, ft_memcpy, ft_memmove, ft_memchr, ft_memcmp, ft_calloc
• String functions: ft_strlen, ft_strlcpy, ft_strlcat, ft_strchr, ft_strrchr, ft_strncmp, ft_strnstr, ft_strdup
• Conversion: ft_atoi

The character classification functions return 1 when the character matches the tested class and 0 otherwise, as required by the subject.

Additional Functions

These functions provide common operations that are useful in later projects:

• ft_substr: creates a substring from a string
• ft_strjoin: joins two strings into a new allocated string
• ft_strtrim: trims characters from the beginning and end of a string
• ft_split: splits a string into a NULL-terminated array of strings
• ft_itoa: converts an integer to a string
• ft_strmapi: creates a new string by applying a function to each character
• ft_striteri: applies a function to each character in place
• ft_putchar_fd, ft_putstr_fd, ft_putendl_fd, ft_putnbr_fd: write output to a file descriptor

Linked List Functions

The library defines the following list structure in libft.h:

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

It also implements these list helpers:

• ft_lstnew
• ft_lstadd_front
• ft_lstsize
• ft_lstlast
• ft_lstadd_back
• ft_lstdelone
• ft_lstclear
• ft_lstiter
• ft_lstmap

Instructions

Compile the library from the repository root:

make

This creates:

libft.a

Clean object files:

make clean

Clean object files and the static library:

make fclean

Rebuild the project from scratch:

make re

To use the library in another C file, include the header and link the archive:

#include "libft.h"

cc -Wall -Wextra -Werror main.c libft.a

Project Rules

• No global variables are used.
• Helper functions, when needed, are declared static.
• The library is created with ar.
• libtool is not used.
• The Makefile provides the required rules: all, clean, fclean, and re.
• The submitted files are the Makefile, libft.h, and ft_*.c source files.

Resources

• man pages for the standard C library functions reimplemented in this project
• The 42 Libft subject, version 19.2
• The OpenBSD manual pages for strlcpy and strlcat
• The GNU C Library documentation
• The C reference documentation at cppreference.com