Experimental Physics and
Industrial Control System

Benjamin Franksen <[email protected]> · Tue, 30 Jan 2007 11:30:59 +0100

On Monday 29 January 2007 18:28, Andrew Johnson wrote:
> I don't think this change is as large as you make it.

Possibly. You have listed some good reasons for most of the changes and I 
appreciate the effort to clean up the syntax (and the code).

The change that had disturbed me most was

> The characters permitted in a bareword parameter (i.e. a filename or
> value that is not inside quotes) have been reduced from the overly wide
> set allowed before; the permitted characters now comprise: a-z A-Z 0-9 _ -
> + : . / \ [ ] < > ;

I thought (mistakenly) that formally allowed was any character except { } 
( ) , $ " = that is, everything that is not a 'delimiter' symbol. I am sure 
I read this somewhere either in the sources or else in some piece of 
documentation. However, I can't seem to find it any longer. Maybe I mixed 
it up with some other EPICS related tool (but which one?). When I look 
again at dbLoadTemplate sources I see that e.g. $ ( and ) are explicitly 
allowed which is porbably not a good idea.

> > One further issue that I would be interested in is: will the
> > corresponding tool on the host side (MSI) be adapted according to the
> > new rules, so that inflating substitutions on host and target side will
> > remain equivalent? (Or have they ever been after dbLoadTemplate was no
> > longer available on the host side?)
>
> The tightening up of the syntax I have done has not affected MSI at all,
> and I don't intend to make any changes to that tool; the two have
> probably never been completely identical in the syntax they will accept
> since they are independently written code, but there is and always will
> be a core syntax that both understand, which is the syntax described in
> the Application Developers' Guide.
>
> If this change prevents an operational site from upgrading to R3.14.9 I
> am willing to write a perl script that fixes any files that are no
> longer accepted by the dbLoadTemplate() command.  However I do expect
> such changes to be minor and probably quicker to fix by hand in most
> cases - quoting some filenames is likely to be the most common change.

I hope you are right.

Cheers
Ben
-- 
"Programming = Mathematics + Murphy's Law" (Dijkstra in EWD1008)

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System