53 lines
1.5 KiB
C
53 lines
1.5 KiB
C
/* ************************************************************************** */
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/* */
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/* ::: :::::::: */
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/* ft_atol.c :+: :+: :+: */
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/* +:+ +:+ +:+ */
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/* By: lderidde <lderidde@student.s19.be> +#+ +:+ +#+ */
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/* +#+#+#+#+#+ +#+ */
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/* Created: 2025/02/11 15:40:16 by lderidde #+# #+# */
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/* Updated: 2025/02/11 15:40:16 by lderidde ### ########.fr */
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/* */
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/* ************************************************************************** */
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#include "../../libft.h"
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static int is_signed(char c, int *sign)
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{
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if (c == '+' || c == '-')
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{
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if (c == '-')
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*sign *= -1;
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return (1);
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}
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return (0);
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}
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long ft_atol(const char *str)
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{
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long res;
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int sign;
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res = 0;
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sign = 1;
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errno = 0;
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while (*str && ((*str >= 9 && *str <= 13) || *str == 32))
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str++;
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if (is_signed(*str, &sign))
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str++;
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while (*str >= '0' && *str <= '9')
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{
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if (((sign > 0) && res >= (LONG_MAX / 10)
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&& (*str - '0' > LONG_MAX % 10))
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|| (sign == -1 && res >= LONG_MAX / 10
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&& *str - '0' > LONG_MAX % 10 + 1))
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{
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errno = ERANGE;
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break ;
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}
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res = (res * 10) + (*str - '0');
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str++;
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}
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return (res * sign);
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}
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