118
this works for me in bash:
svn status | egrep '^\?' | cut -c8- | xargs rm
Seth Reno's is better:
svn status | grep ^\? | cut -c9- | xargs -d \\n rm -r
It handles unversioned folders and spaces in filenames
As per comments below, this only works on files that subversion doesn't know about (status=?). Anything that subversion does know about (including Ignored files/folders) will not be deleted.
If you are using subversion 1.9 or greater you can simply use the svn cleanup command with --remove-unversioned and --remove-ignored options