String buffer management corrected

void    buff_management(char *str, char mode)
{
    static char buff[BUFF_SIZE];
    static char *buff_ptr = buff;

    if (!mode)
    {
        while (*str)
        {
            if (buff_ptr - buff >= BUFF_SIZE - 1)
            {
                write(1, buff, strlen(buff));
                buff_ptr = buff;
                memset(buff_ptr, 0, BUFF_SIZE);
            }
            *buff_ptr = *str;
            str++;
            buff_ptr++;
        }
    }
    else
    {
        write(1, buff, strlen(buff));
        buff_ptr = buff;
        memset(buff_ptr, 0, BUFF_SIZE);
    }
}