% cat CVS/Root
:ext:anoncvs@savannah.gnu.org:/cvsroot/emacs
% find . -path '.*/CVS/Root' -print0 | xargs -0 \
> perl -i -p -e 's/:ext:anoncvs\@(cvs\.)?s/:pserver:anonymous\@cvs.s/'
% cat CVS/Root
:pserver:anonymous@cvs.savannah.gnu.org:/cvsroot/emacs