Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Tue, 31 Jul 2012 18:19:32 -0500

Hi Benjamin,

On 2012-07-31 Benjamin Franksen wrote:
> Am Dienstag, 31. Juli 2012, 18:52:54 schrieb Andrew Johnson:
> > On 2012-07-31 Ralph Lange wrote:
> > > Shouldn't the db parser complain about this?
> >
> > It should print a warning, but we haven't been very strict about the set
> > of allowed characters in the past so I don't think 3.14.x can reject all
> > of the characters that fall outside the set that is documented as legal.
> > I'll add code to warn about space, both quotes, dot and dollar — any
> > others that I should add to that (fairly arbitrary) list?
> 
> the Developer's Guide is fairly precise about it (3.14.12, page 107):

... but the documented restrictions have never been enforced, and there were 
no adverse effects if you did use many of the characters outside of those 
documented limitations.  For example I believe there are sites that use braces 
{} in their record naming convention.  If we are too strict about the 
characters we allow, we risk alienating such sites, making it impossible for 
them to upgrade.

> > The real bug here though is that makeBaseApp.pl should have removed the
> > dot and any other illegal characters from the user-name when it
> > instantiated the example template in the first place.  Bruno's generated
> > example should never have tried to create record names with dots in them
> > at all.
> 
> I am not so sure about this. I think this places too much burden on
>  something as simple as makeBaseApp.pl that just replaces some strings in a
>  (template) directory of files while copting them somewhere else.
>  Ultimately, it is the function that /loads/ a db file that has the
>  responsibility to make the definitive check (after doing a last round of
>  macro substitutions).

The makeBaseApp.pl script already does exactly this kind of filtering on the 
application name to generate the app_RegisterRecordDeviceDriver function name, 
which must be a legal C identifier.  It's not hard...

> For 3.15, I think dbst (or some replacement with similar functionality)
>  should be re-bundled with base and should be used by default (DB_OPT=YES),
>  e.g. in the Makefiles of the makeBaseApp example. This would also have
>  cought the error early.

My solution works, and avoids having to write documentation telling the user 
how to edit their application files if their user name happens to have a . in 
it and they get a nasty error message.  I prefer to avoid the problem from 
occurring at all, rather than just flagging an error when it does.  It's fixed 
in 3.15.0.1 and also in 3.14.12.3 when that comes out.

- Andrew
-- 
Never interrupt your enemy when he is making a mistake.
-- Napoleon Bonaparte

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System