getting svn tag in version

[Andrea Crotti]

Given a project with many eggs, I would like to make it easy to have all 
the version numbers synchronized
to the upper level SVN version.

So for example I might have svn tags
0.1,
0.2
and a development version.
The development version should get version -dev, and the others 0.1 and 0.2

I found few examples around that read and parse the .svn/entries file, 
is it really
the best way to do it?