[Wrapper-user] One more patch...

[Christian B. <kr...@di...>]

hi there -- lot's of cool stuff recently! I understand there is a
release coming up soon, so here is something that I personally find very
useful: cascading configurations. if there is interest, I would be
delighted to see this included in the upcoming version.

cascading configurations: very simple hack, basically it allows to
specify additional configuration files that are loaded after the main
configuration file. if an additional configuration file specifies a
property that is already specified, the value is replaced with the value
from the additional configuration file. if the property hasn't been
specified, it is simply added.

this is very useful if you have to query for certain parameters upon
installation of an app (via an installer or wizard) -- instead of
rewriting the config file, everything that has been queried from the
user can simply be put in an additional configuration file. this also
helps to a certain degree for upgrading, ie. a new base configuration
file can be shipped, but changes that have already been made to an
existing installation will remain in the additional configuration and
don't get lost (as long as the format of the properties does not
drastically change, that is, but still...). it's also useful if you have
to deal with different JVMs (for example IBM on AIX, Sun on Linux),
since for example -server as a JVM parameter makes the IBM JVM very
unhappy from my experience.

here is how this works in my implementation:

./wrapper ../conf/wrapper.conf include.1=../user.conf.1
include.2=../user.conf.2 

and so on. the order that additional configuration properties are
applied is (of course) include.1, include.2, ...

attached are 4 files (wrapper.h, wrapper.c, wrapper_unix.c,
wrapper_win.c) that are changed to implement the described
functionality. the implementation is quick and dirty, but works for me.
it was originally done against 2.2.9, but I just got the latest beta for
2.3.0 (link was in Leif's mail from Mon, 20 Jan 2003 19:39:03 +0900) and
moved the changes over there -- this is hopefully making it easier to
diff against the current version of the code (plus my 2.2.9 was polluted
by other stuff; also, I'm sorry for being too stupid and lazy to learn
how to use diff and patch). since I can make very good use of this
functionality, I would be happy to see this going into the codebase --
this safes me from having to maintain a private fork ;) -- I am neither
in love with my implementation nor with the names I chose for functions
and parameters, so feel free to change all that to comply with your
naming scheme and general ideas if you want.


thanks,


chr.