C programming language • Standard libc Functions • Pointers • Binary Operations • Low-Level Type Conversions • Memory Management • Error Management • Coding Standards (Norm Compliance) • Compilation Automation with Makefile • Basic Git workflow

Libft

Recoding a set of functions from the libc, as well as other utility functions.

Libc functions

External function	Function to Implement
Without any external function	isalpha isdigit isalnum isascii isprint strlen memset bzero memcpy memmove strlcpy strlcat toupper tolower strchr strrchr strncmp memchr memcmp strnstr atoi
Using only malloc	calloc strdup

#include "libft.h"

int	ft_atoi(const char *s)
{
	int					sign;
	unsigned long long	nbr;

	nbr = 0;
	sign = 1;
	while (*s == ' ' || (*s >= '\t' && *s <= '\r'))
		s++;
	if (*s == '-')
	{
		sign *= -1;
		s++;
	}
	else if (*s == '+')
		s++;
	while (*s >= '0' && *s <= '9')
	{
		nbr = (nbr * 10) + (*s - '0');
		s++;
	}
	if (nbr > LLONG_MAX)
		return ((-1) * sign);
	return ((int)(nbr * sign));
}

Non-libc Utility Functions

Function	Description
ft_substr	Allocates (with malloc(3)) and returns a string from the string ’s’. This new string starts at index ’start’ and has a maximum size of ’len’.
ft_strtrim	Allocates (with malloc(3)) and returns a copy of the string ’s1’, without the characters specified in ’set’ at the beginning and the end of the string.
ft_split	Allocates (with malloc(3)) and returns an array of strings obtained by splitting ’s’ using the character ’c’ as a delimiter.
ft_strjoin	Allocates (with malloc(3)) and returns a new string, resulting from the concatenation of s1 and s2.
ft_itoa	Allocates (with malloc(3)) and returns a string representing the integer ’n’ received as an argument. Negative numbers must be handled.
ft_strmapi	Applies the function ’f’ to each character of the string passed as an argument to create a new string resulting from successive applications of ’f’.
ft_striteri	Applies the function ’f’ to each character of the string passed as an argument, and passing its index as the first argument. Each character is passed by address to ’f’ to be modified if necessary.
ft_putchar_fd	Writes the character ’c’ on the given file descriptor.
ft_putstr_fd	Writes the string ’s’ on the given file descriptor.
ft_putendl_fd	Writes the string ’s’ on the given file descriptor followed by a newline.
ft_putnbr_fd	Writes the integer ’n’ on the given file descriptor.

#include "libft.h"

char	*ft_strjoin(char const *s1, char const *s2)
{
	char		*new;
	size_t		i;
	size_t		j;

	if (!s1 || !s2)
		return (NULL);
	i = ft_strlen(s1) + ft_strlen(s2);
	new = malloc(sizeof(char) * (i + 1));
	if (!new)
		return (NULL);
	i = 0;
	j = 0;
	while (s1[i])
		new[j++] = s1[i++];
	i = 0;
	while (s2[i])
	{
		new[j + i] = s2[i];
		i++;
	}
	new[j + i] = '\0';
	return (new);
}

#include "libft.h"

void	ft_putnbr_fd(int n, int fd)
{
	if (n == -2147483648)
		ft_putstr_fd("-2147483648", fd);
	else
	{
		if (n < 0)
		{
			n = -n;
			ft_putchar_fd('-', fd);
		}
		if (n >= 10)
		{
			ft_putnbr_fd(n / 10, fd);
			ft_putnbr_fd(n % 10, fd);
		}
		else
			ft_putchar_fd(n + '0', fd);
	}
}

List manipulation

Function	Description
ft_lstnew	Allocates (with malloc(3)) and returns a new element. The member variable ’content’ is initialized using the value of the parameter ’content’. The variable ’next’ is initialized to NULL.
ft_lst_add_front	Adds the element ’new’ at the beginning of the list.
ft_lst_add_back	Adds the element ’new’ at the end of the list.
ft_lst_size	Counts the number of elements in the list.
ft_lst_last	Returns the last element of the list.
ft_lst_delone	Frees the memory of the element passed as an argument using the function ’del’ then with free(3). The memory of ’next’ must not be freed.
ft_lst_clear	Deletes and frees the memory of the element passed as a parameter, and all the elements that follow, using ’del’ and free(3). Finally, the initial pointer should be set to NULL.
ft_lst_iter	Iterates over the list ’lst’ and applies the function ’f’ to the content of each element.
ft_lst_map	Iterates over the list ’lst’ and applies the function ’f’ to the content of each element. Creates a new list resulting from successive applications of ’f’. The function ’del’ is there to destroy the content of an element if necessary.

#include "libft.h"

void	ft_lstadd_back(t_list **lst, t_list *new)
{
	t_list	*curr;

	if (!*lst)
	{
		*lst = new;
		return ;
	}
	curr = *lst;
	while (curr-> next)
		curr = curr->next;
	curr->next = new;
}