Experimental Physics and
Industrial Control System

"Konrad, Martin via Tech-talk" <tech-talk at aps.anl.gov> · Tue, 9 Jun 2020 14:59:53 +0000

Hi Michael,
> This is an early step towards (maybe) adding restrictions on what
> characters a record name can contain, and in what positions.
> eg. restricting possible first and last characters.
> 
> In particular I'm looking for examples including characters
> beyond the usual alphanumeric separated by ':' or '-'.
> And in what positions they may (or may not) appear.
FRIB uses ':' and '_' to separate name components. Other than that we
only use alphanumeric characters.

The good old Application Developer's Guide [1] contains a section
talking about allowed characters that I would like to quote here:

> 6.3.2 Unquoted Strings
>
> In the summary section, some values are shown as quoted strings and
> some unquoted. The actual rule is that any string consisting of only
> the following characters does not need to be quoted unless it contains
> one of the above keywords:
>
> a-z A-Z 0-9 _ + - : . [ ] < > ;
>
> These are all legal characters for process variable names, although .
> is not allowed in a record name since it separates the record from the
> field name in a PV name. Thus in many cases quotes are not needed
> around record or field names in database files. Any string containing
> a macro does need to be quoted though.

For reference, there was also a discussion in the past about allowed
characters in PV names [2]. I appreciate any efforts to make the
situation more clear to both users and developers.

Cheers,

Martin

[1] https://epics.anl.gov/base/R3-15/6-docs/AppDevGuide.pdf
[2] https://epics.anl.gov/tech-talk/2016/msg01589.php

-- 
Martin Konrad
Facility for Rare Isotope Beams
Michigan State University
640 South Shaw Lane
East Lansing, MI 48824-1321, USA
Tel. 517-908-7253
Email: konrad at frib.msu.edu

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System