ft_printf.c

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

typedef struct		s_flags
{
	int		width;
	int		prec;
	int		p;
}			t_flags;

int g_count;
va_list ap;
t_flags flags;

void	init_flags(void)
{
	flags.width = 0;
	flags.prec = 0;
	flags.p = 0;
}

void	ft_putchar(char c)
{
	write(1, &c, 1);
	g_count++;
}

int 	ft_strlen(char *s)
{
	int i;

	i = 0;
	while (s[i])
		i++;
	return (i);
}

int 	num(int n)
{
	int i;

	i = 0;
	if (n == 0)
		i++;
	while (n != 0)
	{
		n /= 10;
		i++;
	}
	return (i);
}

int 	num_hex(int n)
{
	int i;

	i = 0;
	if (n == 0)
		i++;
	while (n != 0)
	{
		n /= 16;
		i++;
	}
	return (i);
}

int 	ft_atoi(const char *s)
{
	long num;

	num = 0;
	while(*s >= '0' && *s <= '9')
	{
		num = num * 10 + (*s - 48);
		s++;
	}
	return (num);
}

int 	is_num(char c)
{
	if (c >= 48 && c < 58)
		return (1);
	return (0);
}

void	print_str()
{
	char *str;
	int  spaces;
	int preci;
	int i;

	str = va_arg(ap, char*);
	if (!str)
		str = "(null)";
	preci = (flags.p && flags.prec < ft_strlen(str)) ? flags.prec : ft_strlen(str);
	spaces = flags.width - preci;
	i = 0;
	while (spaces > 0)
	{
		ft_putchar(' ');
		spaces--;
	}
	while (i < preci)
	{
		ft_putchar(str[i]);
		i++;
	}
}

void	ft_puthex(unsigned int n)
{
	char *num;

	num = "0123456789abcdef";
	if (n < 16)
		ft_putchar(num[n]);
	else
	{
		ft_puthex(n / 16);
		ft_puthex(n % 16);
	}
}

void	print_hex()
{
	unsigned int x;
	int spaces;
	int preci;
	int i;

	x = va_arg(ap, unsigned int);
	preci = (flags.prec > num_hex(x) ? flags.prec - num_hex(x) : 0);
	spaces = (preci > 0 ) ? flags.width - flags.prec : flags.width - num_hex(x);
	i = -1;
	while (++i < spaces)
		ft_putchar(' ');
	i = -1;
	while (++i < preci)
		ft_putchar('0');
	ft_puthex(x);
}

void	ft_putnbr(int n, int preci)
{
	unsigned int i;

	if (n < 0)
	{
		ft_putchar('-');
		while (preci)
		{
			ft_putchar('0');
			preci--;
		}
		i = -n;
	}
	else
		i = n;
	while (preci)
	{
		ft_putchar('0');
		preci--;
	}
	if (i < 10)
		ft_putchar(i + '0');
	else if (i > 9)
	{
		ft_putnbr(i / 10, preci);
		ft_putnbr(i % 10, preci);
	}
}

void	print_int()
{
	int d;
	int i;
	int spaces;
	int preci;
	int signe;

	d = va_arg(ap, int);
	signe = d < 0 ? 1 : 0;
	preci = (flags.prec > num(d)) ? flags.prec - num(d) : 0;
	spaces = (preci > 0) ? flags.width - (flags.prec + signe) : flags.width - (num(d) + signe);
	i = -1;
	while (++i < spaces)
		ft_putchar(' ');
	ft_putnbr(d, preci);
}

void	ft_check(const char *s, int *i)
{
	if (is_num(s[*i]))
	{
		flags.width = ft_atoi(s + (*i));
		*i += num(flags.width);
	}
	if (s[*i] == '.')
	{
		flags.p = 1;
		(*i)++;
	}
	if (is_num(s[*i]))
	{
		flags.prec = ft_atoi(s + (*i));
		*i += num(flags.prec);
	}
	if (s[*i] == 'd')
		print_int();
	if (s[*i] == 's')
		print_str();
	else if (s[*i] == 'x')
		print_hex();
}

int		ft_printf(const char *s, ...)
{
	int i;

	g_count = 0;
	va_start(ap, s);
	i = 0;
	while (s[i])
	{
		init_flags();
		if (s[i] == '%')
		{
			i++;
			ft_check(s, &i);	
		}
		else
			ft_putchar(s[i]);
		i++;
	}
	va_end(ap);
	return (g_count);
}
int main()
{
   ft_printf("Magic %s is %5d\n", "number", 42);
printf("Magic %s is %5d", "number", 42);
}