Convert String to Integer

#include <stdio.h>
#include <stdint.h>

int custom_atoi(const char *str)
{
    int sign = 1;
    int i = 0;
    int result = 0;

    if(str[i] == '-')
    {
        sign = -1;
        i++;
    }
    else if(str[i] == '+')
    {
        i++;
    }

    while(str[i] >= '0' && str[i] <= '9')
    {
        result = result*10 + (str[i]-'0');
        i++;
    }

    return sign * result;
}

int main()
{
    char str[101];

    fgets(str,sizeof(str),stdin);

    uint8_t i = 0;
    while(str[i])
    {
        if(str[i]=='\n')
        {
            str[i]='\0';
            break;
        }
        i++;
    }

    printf("%d",custom_atoi(str));

    return 0;
}