Convert String to Integer

#include <stdio.h>
#include <stdint.h>
#include <math.h>
int custom_atoi(const char *str) {
    // Your logic here
    char neg = 0;
    signed long integer_val = 0;
    if(*str == '-')
    {
        neg = 1;
        str++;
    }
    else if(*str == '+')
    {
        str++;
    }
    while((*str >= '0' && *str <= '9'))
    {
       integer_val = integer_val*10 + *str - '0';
       str++;
    }


    if(neg == 1)
    {
        integer_val*=-1;
    }
    return integer_val;
}

int main() {
    char str[101];
    fgets(str, sizeof(str), stdin);

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

    printf("%d", custom_atoi(str));
    return 0;
}