src/mlibc/stdlib/atoi.c


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#include <mlibc/math.h>
#include <stddef.h>
#include <stdint.h>
#include <mlibc/string.h>

int atoi(char *str) {
    size_t s_str = strlen(str);
    if (!s_str) return 0;

    uint8_t negative = 0;
    if (str[0] == '-') negative = 1;

    size_t i = 0;
    if (negative) i++;

    int ret = 0;
    for (; i < s_str; i++) {
        ret += (str[i] - '0') * pow(10, (s_str - i) - 1);
    }

    if (negative) ret *= -1;
    return ret;
}