text: #! /usr/bin/env python
  
  # linktree
  #
  # Make a copy of a directory tree with symbolic links to all files in the
  # original tree.
  # All symbolic links go to a special symbolic link at the top, so you
  # can easily fix things if the original source tree moves.
  # See also "mkreal".
  #
  # usage: mklinks oldtree newtree
  
  import sys, os
  
  LINK = '.LINK' # Name of special symlink at the top.
  
  debug = 0
  
  def main():
      if not 3 <= len(sys.argv) <= 4:
          print 'usage:', sys.argv[0], 'oldtree newtree [linkto]'
          return 2
      oldtree, newtree = sys.argv[1], sys.argv[2]
      if len(sys.argv) > 3:
          link = sys.argv[3]
          link_may_fail = 1
      else:
          link = LINK
          link_may_fail = 0
      if not os.path.isdir(oldtree):
          print oldtree + ': not a directory'
          return 1
      try:
          os.mkdir(newtree, 0777)
      except os.error, msg:
          print newtree + ': cannot mkdir:', msg
          return 1
      linkname = os.path.join(newtree, link)
      try:
          os.symlink(os.path.join(os.pardir, oldtree), linkname)
      except os.error, msg:
          if not link_may_fail:
              print linkname + ': cannot symlink:', msg
              return 1
          else:
              print linkname + ': warning: cannot symlink:', msg
      linknames(oldtree, newtree, link)
      return 0
  
  def linknames(old, new, link):
      if debug: print 'linknames', (old, new, link)
      try:
          names = os.listdir(old)
      except os.error, msg:
          print old + ': warning: cannot listdir:', msg
          return
      for name in names:
          if name not in (os.curdir, os.pardir):
              oldname = os.path.join(old, name)
              linkname = os.path.join(link, name)
              newname = os.path.join(new, name)
              if debug > 1: print oldname, newname, linkname
              if os.path.isdir(oldname) and \
                 not os.path.islink(oldname):
                  try:
                      os.mkdir(newname, 0777)
                      ok = 1
                  except:
                      print newname + \
                            ': warning: cannot mkdir:', msg
                      ok = 0
                  if ok:
                      linkname = os.path.join(os.pardir,
                                              linkname)
                      linknames(oldname, newname, linkname)
              else:
                  os.symlink(linkname, newname)
  
  if __name__ == '__main__':
      sys.exit(main())
  