ft_substr.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_substr.c                                        :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: flverge <flverge@student.42.fr>            +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2023/10/02 15:26:41 by flverge           #+#    #+#             */
/*   Updated: 2024/09/22 17:15:13 by flverge          ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"

/**
 * @brief Allocates and returns a substring from the string 's'.
 *
 * The substring begins at index 'start' and is of maximum size 'len'.
 *
 * @param s The string from which to create the substring.
 * @param start The start index of the substring in the string 's'.
 * @param len The maximum length of the substring.
 * @return The substring. NULL if the allocation fails or if 's' is NULL.
 */
char	*ft_substr(char const *s, unsigned int start, size_t len)
{
	char	*buffer;
	size_t	len_s;

	if (!s)
		return (NULL);
	len_s = ft_strlen(s);
	if (start > len_s)
		return (ft_calloc(1, sizeof(char)));
	if (len > ft_strlen(s + start))
		len = ft_strlen(s + start);
	buffer = ft_calloc(len + 1, sizeof(char));
	if (!buffer)
		return (NULL);
	ft_memcpy(buffer, &s[start], len);
	buffer[len] = '\0';
	return (buffer);
}