Experimental Physics and
Industrial Control System

Noboru Yamamoto <[email protected]> · Fri, 02 Nov 2007 08:22:22 +0900

Hi,

Andrew Johnson wrote:
> Heinrich du Toit wrote:
>>
>> Is there 'n lexical analyzer for .db files?
>>
>> I guess there must be something in epics BASE somewhere?
>> But is it written in something like flex that can easily be
>> extended/used or is it some custom code nightmare?
> 
> The IOC's parser is written in flex and antelope (BSD-licensed versions 
> of lex and yacc), the code for which you can find in base/src/dbStatic. 
>  Note that you need to parse a DBD file (to define the record types, 
> fields, menu selections etc.) before you can completely understand a DB 
> file.
> 
> However rather than directly grabbing and trying to use our lex and yacc 
> files I would strongly recommend that you make use of the dbStaticLib 
> library API which permits you to load, manipulate and save DBD and DB 
> files; if you stick with the dbStatic API (documented in Chapter 14 of 
> the EPICS IOC Application Developer's Guide) you're more protected 
> against future changes to the syntax of the DB and DBD files.
I agree with Andrew's comment.

> 
> It is also relatively easy to write a DB file parser in modern scripting 
> languages such as Perl and Python, but it is also easy to omit some 
> obscure pieces of the syntax.  You should be aware that future major 
> releases of Base will probably replace the 'C' dbStatic library with 
> tools written in Perl (which will have a similar Perl library for 
> manipulating the underlying data).
I wrote a simple SWIG interface module for Python.
It bridges dbStaticLib and Python. And add some python code to access to
the database easier.

You can find it at:

http://www-acc.kek.jp/EPICS_Gr/products.html

> 
> HTH,
> 
> - Andrew

Regards,

Noboru Yamamoto
J-pARC control group/EPICS group
J-PARC Center/KEK, JAPAN

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System