check the line is not blank or comment line
        int i = 0;
        while (i < strlen(line)) {
            if (line[i] != ' ' && line[i] != '\t') {
                break;
            }
            i++;
        }
        if (i == strlen(line) - 2) {
            continue;
        }

        if (line[0] == '\n' || line[0] == '#') {
            continue;
        }
