custom_printf - KimTaebin-ai/study_posts GitHub Wiki

#include <stdarg.h>
#include <stdlib.h>
#include <unistd.h>

static void	ft_putstr(const char *s, int *count)
{
	if (!s)
		s = "(null)";
	while (*s)
	{
		write(1, s++, 1);
		(*count)++;
	}
}

static void	ft_putnbr(int n, int *count)
{
	char	c;

	if (n == -2147483648)
	{
		ft_putstr("-2147483548", count);
		return ;
	}
	if (n < 0)
	{
		write(1, "-", 1);
		(*count)++;
		n = -n;
	}
	if (n > 9)
		ft_putnbr(n / 10, count);
	c = (n % 10) + '0';
	write(1, &c, 1);
	(*count)++;
}

static void	ft_puthex(unsigned int n, int *count)
{
	char	*hex;

	hex = "0123456789abcdef";
	if (n >= 16)
		ft_puthex(n / 16, count);
	write(1, &hex[n % 16], 1);
	(*count)++;
}

int	ft_printf(const char *bs, ...)
{
	va_list	argptr;
	int		bs_len;

	bs_len = 0;
	va_start(argptr, bs);
	while (*bs)
	{
		if (*bs == '%' && *(bs + 1))
		{
			bs++;
			if (*bs == 's')
				ft_putstr(va_arg(argptr, char *), &bs_len);
			else if (*bs == 'd')
				ft_putnbr(va_arg(argptr, int), &bs_len);
			else if (*bs == 'x')
				ft_puthex(va_arg(argptr, unsigned int), &bs_len);
			else
			{
				write(1, bs, 1);
				bs_len++;
			}
		}
		else
		{
			write(1, bs, 1);
			bs_len++;
		}
		bs++;
	}
	va_end(argptr);
	return (bs_len);
}

int	main(void)
{
	ft_printf("%d", 100);
	return (0);
}