libft/ft_substr.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_substr.c                                        :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: kcolin <marvin@42.fr>                      +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2024/10/17 11:45:52 by kcolin            #+#    #+#             */
/*   Updated: 2024/10/23 10:46:53 by kcolin           ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

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

static int	min(size_t a, size_t b)
{
	if (a > b)
		return (b);
	return (a);
}

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

	substr_len = 0;
	i = 0;
	while (s[i] != '\0')
	{
		if (i >= start)
			substr_len++;
		if (i >= start + len)
			break ;
		i++;
	}
	if (i < start)
		return (ft_calloc(1, sizeof(char)));
	out = ft_calloc(min(substr_len, len) + 1, sizeof(char));
	if (out == NULL)
		return (NULL);
	ft_strlcpy(out, s + start, min(substr_len, len) + 1);
	return (out);
}

/*
#include <stdio.h> // BAD
#include <stdint.h> // BAD

int	main(void)
{
	char	*data = "This is a long test string.";

	printf("'%s'\n", ft_substr(data, 0, 4));
	printf("'%s'\n", ft_substr(data, 0, SIZE_MAX));
	printf("'%s'\n", ft_substr(data, 15, 4));
	printf("'%s'\n", ft_substr(data, 15, 0));
	printf("'%s'\n", ft_substr(data, 20, 20));
	printf("'%s'\n", ft_substr(data, 100, 27));
}
*/