ft_strnstr.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_strnstr.c                                       :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: adiaz-lo <marvin@42.fr>                    +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2020/01/13 10:02:36 by adiaz-lo          #+#    #+#             */
/*   Updated: 2020/01/13 10:09:15 by adiaz-lo         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

/*
** This function locates the first occurrence of the substring 'to_find' in the
** string 'str' and returns a pointer to this position.
** For further information, please check the Standard C Library Function
** 'strnstr(const char *str, const char *to_find, size_t len)'.
*/

#include "libft.h"

char	*ft_strnstr(const char *str, const char *to_find, size_t len)
{
	size_t	i;
	size_t	j;

	if (!*to_find)
		return ((char *)str);
	i = 0;
	while (str[i] && (size_t)i < len)
	{
		if (str[i] == to_find[0])
		{
			j = 0;
			while (str[i + j] == to_find[j] && i + j < len)
			{
				if (to_find[j + 1] == '\0')
					return ((char *)&str[i]);
				j++;
			}
		}
		i++;
	}
	return (0);
}