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<== Date ==> <== Thread ==>
Subject: Re: Questions from the Static Database Access chapter of the Application Developer's Guide
From: "Johnson, Andrew N. via Tech-talk" <tech-talk at aps.anl.gov>
To: "Wang, Andrew" <wang126 at llnl.gov>
Cc: EPICS tech-talk <tech-talk at aps.anl.gov>
Date: Tue, 1 Feb 2022 00:23:32 +0000
Hi Andy,

On Jan 31, 2022, at 1:53 AM, Wang, Andrew via Tech-talk <tech-talk at aps.anl.gov> wrote:

I have a quick question regarding dbReadDatabase. Based upon my understanding, it seems that it is meant for loading a file containing database definitions, which I presume comes from files with a .dbd extension. However, in Chapter 14.16.1, I noticed that one of the lines of code seems to imply that we can pass .db files into the arguments of dbReadDatabase. I was wondering if that is a typo.

No, both dbReadDatabase() can be used to read either type of file, the IOC has a single parser which handles all of the syntax described in the database definition chapter 6.2.


Additionally, I am a bit curious about how to utilize some of the functions pertaining to record instances. For instance, dbGetNRecords allows us to get the number of record instances for the record type that DBENTRY references. However, I can’t locate a function that allows me to pass a filename to a record instance file with all the record instances within it.

The dbStaticLib API was designed for writing tools to manipulate databases as well as for internal use by the IOC, and it doesn’t encompass everything you need, look at the dbAccessDefs.h header for the dbLoadDatabase() and dbLoadRecords() functions (AppDev chapter 6.10) for instance. Those functions both call dbReadDatabase() to do the actual parsing.

HTH,

- Andrew

-- 
Complexity comes for free, simplicity you have to work for.

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RE: Questions from the Static Database Access chapter of the Application Developer's Guide Wang, Andrew via Tech-talk
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Questions from the Static Database Access chapter of the Application Developer's Guide Wang, Andrew via Tech-talk
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