ft_atoi - gabrielcoelhodacunha-old/42sp-libft GitHub Wiki
Description
Converts the string nptr to an integer.
Implementation
int ft_atoi(const char *nptr)
{
int sign;
long nbr;
remove_whitespaces(&nptr);
sign = determine_sign(&nptr);
nbr = 0;
while (ft_isdigit(*nptr)
&& nbr >= INT_MIN && nbr <= INT_MAX)
nbr = nbr * 10 + (*(nptr++) - '0');
nbr *= sign;
if (nbr < INT_MIN)
return (0);
if (nbr > INT_MAX)
return (-1);
return (nbr);
}
static int determine_sign(const char **nptr)
{
int sign;
sign = 1;
if (**nptr == '-')
sign = -1;
if (**nptr == '-' || **nptr == '+')
(*nptr)++;
return (sign);
}
static void remove_whitespaces(const char **nptr)
{
while (ft_isspace(**nptr))
(*nptr)++;
}
static int ft_isspace(int c)
{
return (c == '\t' || c == '\n' || c == '\v'
|| c == '\f' || c == '\r' || c == ' ');
}