libft/ft_memcpy.c at master · doomangang/libft · GitHub

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/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_memcpy.c                                        :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: jihyjeon < jihyjeon@student.42seoul.kr>    +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2023/10/11 13:51:03 by jihyjeon          #+#    #+#             */
/*   Updated: 2023/11/05 21:46:56 by jihyjeon         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"

void	*ft_memcpy(void *dst, const void *src, size_t n)
{
	unsigned char	*d;
	unsigned char	*s;

	d = dst;
	s = (unsigned char *)src;
	if (!d && !s)
		return (0);
	if (d < s || d >= (s + n))
	{
		while (n--)
		{
			*(d++) = *(s++);
		}
	}
	else
	{
		d += n;
		s += n;
		while (n--)
		{
			*(--d) = *(--s);
		}
	}
	return (dst);
}