A directory under SVN can sometimes contain a lot of unversioned (or ignored) files, e.g. temporary files from a compilation process. These files can be listed as follows:

svn status --no-ignore | grep '^[I?]' | cut -c 9

The following command deletes them all:

svn status --no-ignore | grep '^[I?]' | cut -c 9 | xargs -Ixx rm -rf xx

An additional benefit of these simple one-liners: they can be saved as bash aliases.

Sources