grep in spec file causes rpmbuild to abort with bad exit status

[marks <marks adax com>]

Hi,

I'm using grep in the install section of my spec file to determine
if another file does or does not contain a piece of information.
rpmbuild is aborting with a "bad exit status" message when grep 
does not find the item of interest.

I'd like to have rpmbuild ignore the bad exit status from grep so 
that I can control what is done depending on whether grep finds my 
string or not.

Is there a way to turn off rpmbuild's abort of the entire build
temporarily while I do the grep?

-- 
Thanks,

Mark