Bonus Question :P

[tibberous]

I use this function to store ip address in an int field in the database:

 

function ip2num($ip){

$parts = explode('.', $ip);

$value = 0;

$exp = 0;

foreach($parts as $part)

$value += $part * pow(256, $exp++);

return $value;

}

 

How do I convert back?

[TeddyKiller]

Use CODE or PHP tags.

 

What do you mean "Convert back" ?

[tibberous]

I got it!

 

I took the number an used base_convert($num, 10, 16) to get a series of 8 alpha-numeric characters. Then, I used windows calculator to convert them from base-16 to base-10 2 at a time to get base 256.

 

But, for some reason, the sets are backwords. I only found this out b/c I was playing with my ip address. So, basically, if you get:

 

75.149.00.109

 

You just make it:

 

109.00.149.75

 

So, I kind of solved it, but there is a lot more standard way that just involves modding and dividing. Does anyone know that way?

 

@Teddy:

 

It converts an ip address to a base-10 number, so converting back would be getting the original ip.

[Daniel0]

Uh...

 

ip2long, long2ip

[ignace]

Uh...

 

ip2long, long2ip

 

Makes you wonder why those boys at php.net go through all the trouble?!

[oni-kun]

Uh...

 

ip2long, long2ip

 

Makes you wonder why those boys at php.net go through all the trouble?!

 

And girls. I think?

[tibberous]

Lol. Guess my class on C++ bit-encoding was a waste?

 

 

[ignace]

Guess my class on C++ bit-encoding was a waste?

 

Not if you are writing C++

[Daniel0]

They're in MySQL too, by the way:

 

INET_NTOA(), INET_NTOA()

[TeddyKiller]

They're in MySQL too, by the way:

 

INET_NTOA(), INET_NTOA()

 

There the same?

[Mchl]

No. They just do the same thing. There's exactly one way to convert IP in form of four octets into a 32bit integer.

BTW: Make sure you use UNSIGNED INTEGER in MySQL for storing IPs.

 

[edit]

 

OC the second one is INET_ATON()

[Daniel0]

Heh... yeah the second one (or first one) was supposed to have been INET_ATON().