ft_strjoin.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_strjoin.c                                       :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: rakama <rui20030415@gmail.com>             +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2022/04/12 16:43:22 by rakama            #+#    #+#             */
/*   Updated: 2022/04/26 23:54:04 by rakama           ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"

char	*ft_return_result(char	*result, const char	*s1, const char	*s2)
{
	size_t	len1;
	size_t	len2;

	len1 = ft_strlen(s1);
	len2 = ft_strlen(s2);
	if (result == NULL)
		return (NULL);
	if (s1 == NULL)
	{
		ft_memcpy(result, s2, len2 + 1);
		return (result);
	}
	else if (s2 == NULL)
	{
		ft_memcpy(result, s1, len1 + 1);
		return (result);
	}
	if (s1 == NULL && s2 == NULL)
	{
		*result = '\0';
		return (result);
	}
	return (result);
}

char	*ft_strjoin(char const	*s1, char const	*s2)
{
	size_t	len1;
	size_t	len2;
	char	*result;

	len1 = ft_strlen(s1);
	len2 = ft_strlen(s2);
	result = malloc(sizeof(char) * (len1 + len2) + 1);
	if (result == NULL)
		return (NULL);
	ft_return_result(result, s1, s2);
	ft_memcpy(result, s1, len1);
	ft_memcpy(result + len1, s2, len2 + 1);
	return (result);
}