ft_strtrim.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_strtrim.c                                       :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: jchoy-me <marvin@42.fr>                    +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2023/07/11 14:29:59 by jchoy-me          #+#    #+#             */
/*   Updated: 2023/07/17 16:32:41 by jchoy-me         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "libft.h"

/*
DESCRIPTION:
Allocates (with malloc(3)) and returns a copy of ’s1’ with the characters 
specified in ’set’ removed from the beginning and the end of the string.

PARAMETERS:
s1:		The string to be trimmed.
set:	The reference set of characters to trim.

RETURN VALUE:
The trimmed string.
NULL if the allocation fails.

EXTERNAL FUNCTIONS:
malloc
*/

char	*ft_strtrim(char const *s1, char const *set)
{
	char	*dest;
	int		start;
	int		end;
	int		nbytes;

	if (s1 == NULL || set == NULL)
		return (NULL);
	start = 0;
	end = ft_strlen(s1);
	while (s1[start] != '\0' && ft_strchr(set, s1[start]))
		start++;
	while (end > start && ft_strchr(set, s1[end - 1]))
		end--;
	nbytes = end - start + 1;
	dest = (char *) malloc(sizeof(char) * nbytes);
	if (dest == NULL)
		return (NULL);
	ft_strlcpy(dest, &(s1[start]), nbytes);
	return (dest);
}