Re: more custom C function fun - Mailing list pgsql-general

From Dan \"Heron\" Myers
Subject Re: more custom C function fun
Date
Msg-id 48207BC6.1040508@xnapid.com
Whole thread Raw
In response to Re: more custom C function fun  (Martijn van Oosterhout <kleptog@svana.org>)
Responses Re: more custom C function fun  (Martijn van Oosterhout <kleptog@svana.org>)
List pgsql-general
Martijn van Oosterhout wrote:
> You do realise that VARDATA does not return a null terminated string?

I did not realize that...  but it led me in the right direction.

> Try using something like text_to_cstring or using elog(NOTICE) to
> display what's actually being compared.

I've outputted some things with elog (which is the other thing I needed
to figure this out).

Using DatumToCString(mytextvariable), I get single-character-length
strings that do not match the data actually in the fields.

Using VARDATA(mytextvariable) as the char*, I get things like this (name
obscured) (using strlen to get the string's length):

string: "Hillary Clinton(6611)", length 21
string: "95555551234nton(6611)", length 21

Of course, then I realized that strlen isn't the right tool for the job;
I need: int len = VARSIZE(mytextvariable) - VARHDRSZ;

Using that with the VARDATA as my char*, I get this:

string: "Hillary Clinton(6611)" - length: 21
string: "95555551234" - length: 11

Which is what I need.  Perhaps we could get some documentation about how
to use this stuff?  I was unable to find any on the Postgres site, if
there is any.

Thanks for your help guys :)

- Dan

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