Libft - Library of Functions /42 Lisboa/

This is my first project as a 42 Lisboa student, where I had to create a library containing multiple libc re-coded functions and also create new ones that are not included in the standard C library.

So, the project was divided in 3 parts:

• In the first part, I re-coded some functions of the standard C library, following the steps in their man, making them have the same behaviors and prototypes as the original ones. All of their names had to start by the prefix "ft_XXX.c", according to the pdf project's instructions;

• Meanwhile, in the second part, I coded some additional functions that are not present in the standard C library, or are included in a different form;

• And in the last part, I worked with the concept of linked list functions, as a bonus for receiving extra points in my project's evaluation.

To do these steps, I worked with 3 different types of files, them being:

• .c -> Is the file format that all of the functions written must have;

• .h -> It represents the header for the functions, which is useful because I just needed to include it once, and all of the .c files would read from it - by doing this I don't need to put the header of a function (#include <stdio.h>, for example) in every single file. Also, if one function references another function of the library, the header file saves time once I don't need to write the function again;

• Makefile -> Is the file that compiled all of the functions and header of my project as a whole - that way I didn't need to create an "int main" and compile the functions with the "gcc" flags. I only needed to type "make" once I had it created.

Functions:

A) Functions from the library <ctype.h>:

• ft_isalpha - used to check if the param is an alphabetic character ( a-z || A-Z ).
• ft_isdigit - used to check if the param is a digit ( 0-9 ).
• ft_isalnum - used to check if the param is an alphanumeric character ( a-z || A-Z || 0-9 ).
• ft_isprint - used to check if the param is a printable character.
• ft_isascii - used to check if the param is part of the ASCII character set.
• ft_tolower - used to convert char to lowercase characters.
• ft_toupper - used to convert char to uppercase characters.

B) Functions from the library <string.h>:

• ft_strlen - used to calculate the length of a string.
• ft_strchr - used to locate the first occurence of a character in string, returning a pointer to it.
• ft_strrchr - used to locate the last occurence of a character in string.
• ft_strncmp - used to compare two strings, returning a value according to the difference of the first character they differ.
• ft_strnstr - used to locate a substring in a string.
• ft_strdup - creates a duplicate for the string passed as parameter.
• ft_strlcpy - used to copy a string to an specific size.
• ft_strlcat - used to concatenate a string to an specific size.
• ft_bzero - used to write a specific amount of zero bytes to a string.
• ft_memset - used to fill the memory with a constant byte.
• ft_memcpy - used to copy memory area, returning original value of dst.
• ft_memmove - used to copy memory area like memcpy, but more useful if src and dst overlap.
• ft_memchr - used to scan memory to find the first occurence of a character in a buffer.
• ft_memcmp - used to compare different memory areas.

C) Functions from the library <stdlib.h>:

• ft_atoi - used to convert a string to an integer.
• ft_calloc - used to allocate memory and set its bytes' values to 0.

D) Non-standard functions:

• ft_substr - used to return a substring from a string.
• ft_strjoin - used to concatenate two strings.
• ft_strtrim - used to trim the beginning and end of string with specific set of chars.
• ft_split -used to split a string using a char as parameter.
• ft_itoa - used to convert a number into a string.
• ft_strmapi - used to apply a function to each character of a string.
• ft_striteri - used to apply a function to each character of a string like ft_strmapi - but not using malloc.
• ft_putchar_fd - used to output a char to a file descriptor.
• ft_putstr_fd - used to output a string to a file descriptor.
• ft_putendl_fd - used to output a string to a file descriptor, followed by a new line.
• ft_putnbr_fd - used to output a number to a file descriptor.

E) Linked list functions:

• ft_lstnew - used to create a new node in a list.
• ft_lstadd_front - used to add a new node at the beginning of a list.
• ft_lstsize - used to count the number of nodes inside a list.
• ft_lstlast - used to return the address of the last node of a list.
• ft_lstadd_back - used to add a new node at the end of a list.
• ft_lstclear - used to delete a node's content and free its memory from the list.
• ft_lstdelone - used to delete a node's content and free its memory from the list.
• ft_lstiter - used to apply a function to each node of a list.
• ft_lstmap - used to apply a function to each element of a list, creating and returning a new list.