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ft_atoi.c
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ft_atoi.c
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/* ************************************************************************** */
/* */
/* ::: :::::::: */
/* ft_atoi.c :+: :+: :+: */
/* +:+ +:+ +:+ */
/* By: yuotsuka <yuotsuka@student.42.fr> +#+ +:+ +#+ */
/* +#+#+#+#+#+ +#+ */
/* Created: 2024/04/18 20:59:19 by yuotsuka #+# #+# */
/* Updated: 2024/05/22 20:21:14 by yuotsuka ### ########.fr */
/* */
/* ************************************************************************** */
#include "libft.h"
static int ft_isspace(int c)
{
const char *str;
int i;
i = 0;
str = " \n\t\v\f\r";
while (c != str[i])
{
if (str[i] == '\0')
return (0);
i++;
}
return (1);
}
static long ft_atol(const char *s)
{
long res;
long coeff;
res = 0;
coeff = -1ul >> 1;
while (*s && ft_isspace(*s))
s++;
if (*s == '+' || *s == '-')
if (*s++ == '-')
coeff = ~(-1ul >> 1);
while (*s && ft_isdigit(*s))
{
if (__builtin_mul_overflow(res, 10, &res)
|| ((0 < coeff) && __builtin_add_overflow(res, *s - '0', &res))
|| ((coeff < 0) && __builtin_sub_overflow(res, *s - '0', &res)))
return (coeff);
s++;
}
return (res);
}
int ft_atoi(const char *nptr)
{
return (ft_atol(nptr));
}
// int main()
// {
// char *num = " \t +1234aaaa";
// __builtin_printf("%d\n", ft_atoi(num));
// __builtin_printf("%d", atoi(num));
// }