libft/ft_strnstr.c at master · FindingMiGo/libft · GitHub

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/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_strnstr.c                                       :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: user <user@student.42tokyo.jp>             +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2023/04/29 15:30:00 by user              #+#    #+#             */
/*   Updated: 2023/04/29 15:30:00 by user             ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"

char	*ft_strnstr(const char *s1, const char *s2, size_t n)
{
	size_t	i;
	size_t	j;

	if (!s2[0])
		return ((char *)s1);
	i = 0;
	while (s1[i] && i < n)
	{
		j = 0;
		while (s1[i + j] == s2[j] && s1[i + j] && s2[j] && i + j < n)
		{
			if (!s2[j + 1])
				return ((char *)&s1[i]);
			j++;
		}
		i++;
	}
	return (NULL);
}