Normalize INTERVAL ouput format in a db driver

Hi all,

Just testing 8.4rc2 INTERVALs...

According to the doc, INTERVAL output format is controlled by SET intervalstyle.

I am writing an interface/driver and need a solution to fetch/convert interval
values independently from the current format settings...

I could force my driver to implicitly set the intervalstyle to iso_8601, but I
would prefer to leave this in the hands of the programmer...

Imagine you have to write and ODBC interface/driver with libpq that must support
the SQLINTERVAL C structure, how would you deal with PostgreSQL intervals?

Is it possible to query the current intervalstyle?

Thanks!
Seb