Libft - My C Standard Library

My implementation of some of the Standard C Library functions including some additional useful functions.

What is libft?

Libft is an individual project at 42 that requires us to re-create some C standard library functions including some additional ones that can be used later to build a library of useful functions for the rest of the program.

Badge

Objectives

• Unix logic

Skills

• Algorithms & AI
• Imperative programming
• Rigor

My grade

Getting started

Follow the steps below

# Clone the project and access the folder
git clone https://github.com/wwwwelton/libft && cd libft/

# Run Make so you can build the library
make

# Run Make with bonus if you want chained lists manipulation functions
make bonus

# Compile your main with the library, example:
clang main.c libft.a

# Execute your program
./a.out

# Clean output objects with
make fclean

# Well done!

Libft / C Standard Library table reference

Each functions has the prefix "ft_" which means forty two.

C Library <ctype.h>
Libft	Description
ft_isalnum	Checks whether the passed character is alphanumeric.
ft_isalpha	Checks whether the passed character is alphabetic.
ft_isascii	Checks whether the passed character is ASCII.
ft_isdigit	Checks whether the passed character is decimal digit.
ft_isprint	Checks whether the passed character is printable.
ft_tolower	Converts uppercase letters to lowercase.
ft_toupper	Converts lowercase letters to uppercase.
C Library <string.h>
Libft	Description
ft_bzero	Erases the data in the n bytes of the memory block. (Write zeroes)
ft_memchr	Searches for the first occurrence of the character c (an unsigned char) in the first n bytes of the string.
ft_memcmp	Compares the first n bytes of str1 and str2.
ft_memcpy	Copies n characters from src to dest.
ft_memmove	Copies n characters from src to dest. (Non destructive manner)
ft_memset	Copies the character c (an unsigned char) to the first n characters of the string.
ft_strchr	Searches for the first occurrence of the character c (an unsigned char) in the string.
ft_strlcat	Appends string src to the end of dst. It will append at most dstsize - strlen(dst) - 1 characters.
ft_strlcpy	Copies up to dstsize - 1 characters from the string src to dst.
ft_strlen	Computes the length of the string but not including the terminating null character.
ft_strncmp	Compares at most the first n bytes of str1 and str2.
ft_strnstr	Locates the first occurrence of the null-terminated string little in the string big, where not more than len characters are searched.
ft_strrchr	Searches for the last occurrence of the character c (an unsigned char) in the string.
C Library <stdlib.h>
Libft	Description
ft_atoi	Converts the string to an integer (type int).
ft_calloc	Allocates the requested memory initialized to zero bytes.
Non-stantard C Library
Libft	Description
ft_itoa	Converts the int to a string (type char *).
ft_putchar_fd	Outputs the character 'c' to the given file descriptor.
ft_putendl_fd	Outputs the string 's' to the given file descriptor, followed by a newline.
ft_putnbr_fd	Outputs the integer 'n' to the given file descriptor.
ft_putstr_fd	Outputs the string 's' to the given file descriptor.
ft_strdup	Returns a pointer to a null-terminated byte string, which is a duplicate of the string.
ft_striteri	Applies a function to each character of the string.
ft_strjoin	Returns a new string, which is the result of the concatenation of 's1' and 's2'.
ft_strmapi	Applies a function to each character of the string 's' to create a new string.
ft_strtrim	Returns a copy of 's1' with the characters specified in 'set' removed from the beginning and the end of the string.
ft_substr	Returns a substring from the string 's'. The substring begins at index 'start' and is of maximum size 'len'.
Chained lists manipulation
Libft	Description
ft_lstadd_back	Adds the element at the end of the list.
ft_lstadd_front	Adds the element at the beginning of the list.
ft_lstclear	Deletes and frees the given element and every successor of that element, using a given function and free.
ft_lstdelone	Takes as a parameter an element and frees the memory of the element’s content using a function given as a parameter and free the element.
ft_lstiter	Iterates the list and applies a function to the content of each element.
ft_lstlast	Returns the last element of the list.
ft_lstmap	Iterates the list and applies a function to the content of each element. Creates a new list resulting of the successive applications of the function. A 'del' function is used to delete the content of an element if needed.
ft_lstnew	Returns a new element.
ft_lstsize	Counts the number of elements in a list.
Personal functions
Libft	Description
ft_atol	Converts the string to a long integer (type long int).
ft_char_to_str	Creates a string of size len filled with the unsigned char passed as parameter.
ft_free_ptr	Deallocates a pointer memory address and sets to NULL.
ft_str_replace	Searches for the first occurrence of the string old_word in the string str and replaces with the string new_word. The memory address of the string str passed as a parameter will be freed.
ft_str_toupper	Converts lowercase letters of the string to uppercase.
ft_strmerge	Returns a new string, which is the result of the concatenation of 's1' and 's2'. The memory address of 's1' and 's2' will be freed.
ft_uitoa_base	Returns a string representing the unsigned integer in the base received as an argument.
ft_get_next_line	Return a string including \n if is a line. In case of the file dont have \n return a string without \n, NULL if the file is empty or error occurred.

Updating

The project is updated regularly with new functions that could be useful for other projects.

📝 License

This project is licensed under the GNU General Public License v3.0 - see the LICENSE file for details.

---

Made by Welton Leite 👋 See my linkedin