ft_strncasecmp.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_strncasecmp.c                                   :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: bnoufel <bnoufel@student.42.fr>            +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2020/02/08 16:09:04 by bnoufel           #+#    #+#             */
/*   Updated: 2020/02/08 19:49:38 by bnoufel          ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "str.h"
#include "char.h"

/*
**	@param const char *s1
**	@param const char *s2
**	@param size_t n
**	The ft_strncasecmp functions lexicographically
**		compare the null-terminated strings s1 and s2 with no case sensitive.
**	The ft_strncasecmp function compares not more than n characters.
**	Because ft_strncasecmp is designed for comparing strings rather
**		than binary data, characters that appear after a `\0'
**		character are not compared.
************************* RETURN VALUES **********************************
**	The ft_strncasecmp functions return an integer greater than, equal to,
**		or less than 0, according as the string s1 is greater than, equal to,
**		or less than the string s2.
**	The comparison is done using unsigned characters, so that `\200' is greater
**	than `\0'.
*/

static size_t	ft_get_big_len(const char *s1, const char *s2, size_t n)
{
	size_t	ls1;
	size_t	ls2;

	ls1 = ft_strlen(s1);
	ls2 = ft_strlen(s2);
	if (ls1 < n)
		n = ls1 + 1;
	if (ls2 < n)
		n = ls2 + 1;
	return (n);
}

static int	return_result_strcasecmp(uint8_t *str1, uint8_t *str2, size_t i)
{
	if (ft_tolower(str1[i]) < ft_tolower(str2[i]))
		return (-1);
	return (1);
}

int	ft_strncasecmp(const char *s1, const char *s2, size_t n)
{
	size_t	len;
	size_t	i;
	uint8_t	*str1;
	uint8_t	*str2;

	str1 = (uint8_t *)s1;
	str2 = (uint8_t *)s2;
	if (str1 == str2)
		return (0);
	i = 0;
	len = ft_get_big_len(s1, s2, n);
	while (i < len)
	{
		if (ft_tolower(str1[i]) != ft_tolower(str2[i]))
			return (return_result_strcasecmp(str1, str2, i));
		i++;
	}
	return (0);
}