Re: A standard package for config files is needed

[Jacob Sparre Andersen <sparre@nbi.dk>]

Preben Randhol wrote:

> On the GtkAda list there has been some discussion on making a standard
> package for reading/writing configuration files. As most programs need
> this it would be very nice with a small, platform independant, robust
> but easy to use package.

Yes.

If we take a look at the specification (API) side of things
first, then I think such a package would need:

 + (generic?) routines to read and write primitive Ada types
   from/to the configuration data.

 + The data should be stored as key-value pairs, possibly
   embedded in in a hierarchical system of sections.

 + A routine for syncronising the configuration data with
   the external storage in case that is relevant.

 + An option to select another source/target than the
   default storage of the configuration data.

Are there more things we should keep in mind, when
discussing the specification for a simple configuration
management package?

If we take a look at the implementation (file format) side
of things, there are a few things worth noting:

 + Using the same file format on all systems makes it
   slightly easier to write documentation for programs using
   the package (unless the package includes a function
   returning the file format documentation).

 + Using a text based file format makes it easier to copy
   configuration files between different platforms.

 + Using a text based file format allows users to use
   independent tools (for example text editors) to modify
   the configuration.

 + Using a platform specific binary format may make access
   to the configuration data faster.

 + Using typical (or standard) configuration management for
   the individual platforms, will allow users to configure
   programs in a way they are familiar with.

And since the specification and implementation sides of
things can be relatively independent of each other, nothing
prevents us from writing more than one implementation, so
everybody can get to use their choice of configuration files
(also for programs written by other Ada programmers ;-).

Jacob
-- 
"Those who profess to favor freedom and yet depreciate
 agitation, are people who want crops without ploughing the
 ground; they want rain without thunder and lightning; they
 want the ocean without the roar of its waters."
                                        -- Frederick Douglas