Experimental Physics and
Industrial Control System

"Hu, Yong via Tech-talk" <tech-talk at aps.anl.gov> · Wed, 10 Jun 2020 01:33:47 +0000

Michael,

When you say "restrictions", does that mean a newer version of EPICS IOC will fail to load a .db file in which a record name contains a "weird" character?
If the IOC fails to load .db because it does not follow the new rules/restrictions, facilities that have already used "weird" characters will suffer badly when they upgrade EPICS base to a newer version. 

Yong

On 6/8/20, 5:09 PM, "Tech-talk on behalf of Michael Davidsaver via Tech-talk" <tech-talk-bounces at aps.anl.gov on behalf of tech-talk at aps.anl.gov> wrote:

    I'm looking to collect examples of epics record names in the wild.

    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.

    An example from the NSLS2 naming convention (for which I am have
    some responsibility).

    > TST{evm:1D-DlyGen:31}Evt:Trig2-SP

    Which is notable for containing "{" and "}" in the middle.

    As background.  At present, records can be created with almost
    any characters in a name.

    > record(ai, "a b") {}
    > record(ai, "x.y") {}
    > record(ai, "x\"") {}

    However, record names including '.' can't be addressed and aren't
    very useful.  Further, names including spaces can't be targeted
    by links.

    On the subject of links.  Dirk was surprised to find that
    the syntax for link parsing treats "[0]" as a record name,
    but "[0,1]" as a constant array.

    https://urldefense.com/v3/__https://bugs.launchpad.net/epics-base/*bug/1882520__;Kw!!P4SdNyxKAPE!TwNJ4RpksYZmN8YbfgjiN7Y3igc4486VOLcj-_1L1KUqPcMdbvxVXH_bSrI3$ 

    Rather than carving out another exception, I'd like to look at
    coding a general rule.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System