ft_strncmp.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_strncmp.c                                       :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: lclerc <lclerc@student.42.fr>              +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2022/10/29 16:14:13 by lclerc            #+#    #+#             */
/*   Updated: 2022/11/23 16:02:48 by lclerc           ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

/*
 * DESCRIPTION
 * The strcmp() and strncmp() functions lexicographically compare the null-
 * terminated strings s1 and s2.
 * 
 * The strncmp() function compares not more than n characters. Because strncmp()
 * is designed for comparing strings rather than binary data, characters that 
 * appear after a `\0' character are not compared.
 * 
 * RETURN VALUES
 * The strcmp() and strncmp() 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'.
 */

#include "libft.h"

int	ft_strncmp(const char *s1, const char *s2, size_t n)
{
	size_t	i;

	i = 1;
	if (n == 0)
		return (0);
	while ((*s1 == *s2 && (i < n)) && ((*s1 != '\0') && (*s2 != '\0')))
	{
		s1++;
		s2++;
		i++;
	}
	return ((unsigned char)*s1 - (unsigned char)*s2);
}