A funny recipe.

According to a recent book about MySQL, this is the recipe to convert an IP address into an integer, with the purpose of using it as server-ID.

1. Take for example 10.0.159.22
2. Using a calculator (!!!), convert each of the four numbers to hexadecimal (you get 0a.00.9f.16)
3. Then glue the four hexadecimal numbers together, after removing the dots, and, again with the calculator, convert them to decimal (0a009f16HEX=167812886DEC)
4. Use this number (167812886) as your server ID in the options file.

Brilliant, eh?

Had the authors searched the MySQL manual for "IP address", they would have found the INET_ATON function, which can be used like this:

select inet_aton('10.0.159.22');
+--------------------------+
| inet_aton('10.0.159.22') |
+--------------------------+
|                167812886 |
+--------------------------+

Update.
Of course, if you want to ignore INET_ATON and avoid using a calculator, you can still leverage the server to do something like this:

delimiter //
drop function if exists redundant_inet_aton //
create function redundant_inet_aton(IP varchar(16))
returns bigint
deterministic
begin
    return conv( 
      concat(
        lpad(hex(substring_index(IP, '.', 1)+0),2,'0'),
        lpad(hex(substring_index(
                    substring_index(IP, '.', 2),
                 '.', -1) +0 ),2,'0'), 
        lpad(hex(substring_index(
                    substring_index(IP, '.', 3),
                 '.', -1) +0 ),2,'0'),
        lpad(hex(substring_index(IP, '.', -1) +0),2,'0') 
      ), 
        16,10);
end //
#
# Probably good for an obfuscated code contest
#
delimiter ;

#
# testing the new function
#
select IP, redundant_inet_aton(IP), inet_aton(IP)
    from (
               SELECT '10.0.159.22' AS IP 
        UNION  SELECT '192.168.2.6' 
        UNION  SELECT '127.0.0.1' 
        UNION  SELECT '10.176.1.15' 
        UNION  SELECT '173.194.36.104' 
    ) as t;
+----------------+-------------------------+---------------+
| IP             | redundant_inet_aton(IP) | inet_aton(IP) |
+----------------+-------------------------+---------------+
| 10.0.159.22    |               167812886 |     167812886 |
| 192.168.2.6    |              3232236038 |    3232236038 |
| 127.0.0.1      |              2130706433 |    2130706433 |
| 10.176.1.15    |               179306767 |     179306767 |
| 173.194.36.104 |              2915181672 |    2915181672 |
+----------------+-------------------------+---------------+