Libft/ft_substr.c at main · tigran-sargsyan-w/Libft · GitHub

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/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_substr.c                                        :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: tsargsya <marvin@42.fr>                    +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2024/12/09 16:00:23 by tsargsya          #+#    #+#             */
/*   Updated: 2024/12/12 13:52:55 by tsargsya         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"
#include <stdlib.h>

static char	*ft_return_empty_str(void)
{
	char	*res;

	res = malloc(1);
	if (!res)
		return (NULL);
	res[0] = '\0';
	return (res);
}

char	*ft_substr(char const *s, unsigned int start, size_t len)
{
	char	*res;
	size_t	s_len;
	size_t	substr_len;

	if (!s)
		return (NULL);
	s_len = ft_strlen(s);
	if (start >= s_len)
		return (ft_return_empty_str());
	substr_len = s_len - start;
	if (substr_len > len)
		substr_len = len;
	res = malloc(substr_len + 1);
	if (!res)
		return (NULL);
	ft_strlcpy(res, s + start, substr_len + 1);
	return (res);
}