Re: inet value validation

[Andreas Kretschmer <akretschmer(at)spamfence(dot)net>]

pgsql-general(at)list(dot)coretech(dot)ro <pgsql-general(at)list(dot)coretech(dot)ro> schrieb:

> 
> hello,
> 
> I want to write a function to validate an inet data type, but I figure that 
> postgres should already have such a function to use before inserting values 
> in inet type columns.
> is it possible to access postgres's validation function for inet types ? I 
> have snooped through the catalogs but I can not find such a function.

You can try to cast a string into inet like this:

test=# select '127.0.0.255'::inet;
    inet
-------------
 127.0.0.255
(1 row)

test=# select '127.0.0.256'::inet;
ERROR:  invalid input syntax for type inet: "127.0.0.256"


Now you can write a little function to do this:

,----[  a little function  ]
| create or replace function check_ip(varchar) returns bool as $$
| declare
|         i inet;
| begin
|         i := $1::inet;
|         return 't'::bool;
|         EXCEPTION WHEN invalid_text_representation then
|                 return 'f'::bool;
| end;
| $$ language plpgsql immutable strict;
`----

You can use this function now inside a transaction.



HTH, Andreas
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