Recursively Remove SVN files

You want to traverse a directory tree and see if it contains anything other than a directory. This is beyond rm's capabilities. You need other tools such as find. You can delete the empty directories under a given directory this way (-depth causes parent directories that become empty to be deleted as well):

find "$x" -depth -type d -exec rmdir {} +

Here is a function which, for each argument, deletes the argument if it is a non-directory file or a directory tree not containing anything other than directories. Note that this function isn't atomic: if one of the arguments changes while it's running, you may end up with an error message, but it's safe in that it won't delete any non-directory inside a directory passed as argument.

rm () {
  ret=0
  for x; do
    case $x in -*) x=./$x;; esac
    if [ -d "$x" ]; then
      if [ -n "$(find "$x" ! -type d | head -n 1)" ]; then
        echo 1>&2 "$x: non-empty directory tree"
        ret=2
      else
        find "$x" -depth -exec rmdir {} +
        if [ -d "$x" ]; then ret=2; fi
      fi
    else
      command rm "$x" || [ $ret -gt 1 ] || ret=2
    fi
  done
  return $ret
}

You can do:

find . -exec ./is_dir.py {} \; -o -print

It will list everything that is not a directory. Assuming that is_dir.py is executable (chmod +x is_dir.py) and contains something like:

#!/usr/bin/env python

import sys
import os

if os.path.isdir(sys.argv[1]):
    sys.exit(0)
sys.exit(1)

And if is_dir.py generates output of its own, you can do:

 rm -f nondir.lst
 find . -exec ./is_dir.py {} \; -o -exec echo  {} >> nondir.lst \;

so that its outoput doesn't get mixed with the list of names for which is_dir.py fails.