Thread: Way to reverse ordering of an IP ... ?

for Reverse DNS purposes, I'd like to reverse an IP ...

ie: 200.46.204.1 would become 1.204.46.200

Is there an easy way of doing this *short* of writing a plpgsql function?

I've checked the docs, and found the substring() function that allows for 
using a regex, which I thought might allow this, but can't seem to figure 
out a proper format for it ;(

If I have to write a function to do it, fine ... just wanted to make sure 
I wasn't missing something first ...

----
Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email . scrappy@hub.org                              MSN . scrappy@hub.org
Yahoo . yscrappy               Skype: hub.org        ICQ . 7615664

pgsql-sql-owner@postgresql.org wrote:

> for Reverse DNS purposes, I'd like to reverse an IP ...
> 
> ie: 200.46.204.1 would become 1.204.46.200
> 
> Is there an easy way of doing this *short* of writing a
> plpgsql function?
> 
> I've checked the docs, and found the substring() function
> that allows for using a regex, which I thought might allow
> this, but can't seem to figure out a proper format for it ;(
> 
> If I have to write a function to do it, fine ... just wanted
> to make sure I wasn't missing something first ...


Hi,

You can use (\d+)\.(\d+)\.(\d+)\.(\d+) for the match, and \4.\3.\2.\1 for the replacement in your Regexp.

Cheers,

----------------------------------
Philippe Lang, Ing. Dipl. EPFL
Attik System
rte de la Fonderie 2
1700 Fribourg
Switzerland
http://www.attiksystem.ch

Tel:  +41 (26) 422 13 75
Fax:  +41 (26) 422 13 76