ft_ulongtohex.c

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/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   ft_ulongtohex.c                                    :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: tspoof <tspoof@student.hive.fi>            +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2022/12/02 23:20:01 by tspoof            #+#    #+#             */
/*   Updated: 2022/12/08 17:22:22 by tspoof           ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */
 
#include "libft.h"
 
static int  ft_hex_char_count(unsigned long n)
{
    int     i;
 
    i = 1;
    while (n >= 16)
    {
        n = n / 16;
        i++;
    }
    return (i);
}
 
static char ft_decimal16_to_hex(int dec)
{
    if (dec < 10)
        return (dec + '0');
    if (dec == 10)
        return ('a');
    if (dec == 11)
        return ('b');
    if (dec == 12)
        return ('c');
    if (dec == 13)
        return ('d');
    if (dec == 14)
        return ('e');
    if (dec == 15)
        return ('f');
    return (0);
}
 
char    *ft_ulongtohex(unsigned long n)
{
    char    *str;
    int     len;
    int     hex;
 
    len = ft_hex_char_count(n);
    str = (char *)ft_calloc(len + 1, sizeof(char));
    if (!str)
        return (NULL);
    while (len)
    {
        hex = ft_decimal16_to_hex(n % 16);
        str[len - 1] = hex;
        n = n / 16;
        len--;
    }
    return (str);
}