--- In ib-support@y..., Doug Chamberlin <yahoogroups@a...> wrote:

> I have zero experience with UDFs on non-Windows systems. However,
> perhaps
> there is a clue to the problem in that the error message
> says "F_MODULO is
> not defined" (all uppercase) when you have previously used lower
> case to
> define everything.

Doug, Bill, John, Senthil, big thanx for your quick replies. I got it
to work, it was a problem with upper case letters afterall. I also
learned a few things, so if someone searches this group's archive
later:

If you want to make your own udf, don't rely on manuals ;) or
isc_config file which states this:

# Where values are commented out the default value
# (which is usually show as well) applies.

and further below...

#EXTERNAL_FUNCTION_DIRECTORY "/opt/interbase/udf"

The default instalation directory (when using .rpm file) on RH linux
for Firebird 1.0 is /opt/interbase/, and the instalation
creates /opt/interbase/UDF (note the upper case) which is the place
user should place their udf-libs.

To test this, I also compiled FreeUDFLibC, and it copied to UDF
directory, and it worked.