Experimental Physics and
Industrial Control System

[email protected] (William Lupton) · Mon, 5 Feb 96 11:54:29 HST

Dear all,

  Many EPICS tools use a $(macro) syntax to substitute macros, and a
"macro1=value1,macro2=value2" syntax on tool invocation to set macro
values.

  The code to perform the substitutions exists in several places and
does not behave identically under various boundary conditions (one
thing I have noted recently is that "bill=,fred=xxx" does not substitute
an empty string for $(bill)). Also there are places where macro substitution
would be useful but, as far as I am aware, is not available, e.g. in
alh configuration files (currently we are using the C pre-processor here).

  I would like to propose:

a) providing a single library to handle definition of and substitution of
   macros with the $(macro) syntax

b) providing a standalone filter which can act as a pre-processor and which
   will support file inclusion and macro (re-)definition

c) migrating EPICS tools to use the (a) library

The routines in base/src/dbtools come close to (a) but they do not permit
macro (re-)definition.

  Any comments? I volunteer to solicit input and to do the work.

  William

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System