1  #! /usr/bin/env python3
       2  
       3  # linktree
       4  #
       5  # Make a copy of a directory tree with symbolic links to all files in the
       6  # original tree.
       7  # All symbolic links go to a special symbolic link at the top, so you
       8  # can easily fix things if the original source tree moves.
       9  # See also "mkreal".
      10  #
      11  # usage: mklinks oldtree newtree
      12  
      13  import sys, os
      14  
      15  LINK = '.LINK' # Name of special symlink at the top.
      16  
      17  debug = 0
      18  
      19  def main():
      20      if not 3 <= len(sys.argv) <= 4:
      21          print('usage:', sys.argv[0], 'oldtree newtree [linkto]')
      22          return 2
      23      oldtree, newtree = sys.argv[1], sys.argv[2]
      24      if len(sys.argv) > 3:
      25          link = sys.argv[3]
      26          link_may_fail = 1
      27      else:
      28          link = LINK
      29          link_may_fail = 0
      30      if not os.path.isdir(oldtree):
      31          print(oldtree + ': not a directory')
      32          return 1
      33      try:
      34          os.mkdir(newtree, 0o777)
      35      except OSError as msg:
      36          print(newtree + ': cannot mkdir:', msg)
      37          return 1
      38      linkname = os.path.join(newtree, link)
      39      try:
      40          os.symlink(os.path.join(os.pardir, oldtree), linkname)
      41      except OSError as msg:
      42          if not link_may_fail:
      43              print(linkname + ': cannot symlink:', msg)
      44              return 1
      45          else:
      46              print(linkname + ': warning: cannot symlink:', msg)
      47      linknames(oldtree, newtree, link)
      48      return 0
      49  
      50  def linknames(old, new, link):
      51      if debug: print('linknames', (old, new, link))
      52      try:
      53          names = os.listdir(old)
      54      except OSError as msg:
      55          print(old + ': warning: cannot listdir:', msg)
      56          return
      57      for name in names:
      58          if name not in (os.curdir, os.pardir):
      59              oldname = os.path.join(old, name)
      60              linkname = os.path.join(link, name)
      61              newname = os.path.join(new, name)
      62              if debug > 1: print(oldname, newname, linkname)
      63              if os.path.isdir(oldname) and \
      64                 not os.path.islink(oldname):
      65                  try:
      66                      os.mkdir(newname, 0o777)
      67                      ok = 1
      68                  except:
      69                      print(newname + \
      70                            ': warning: cannot mkdir:', msg)
      71                      ok = 0
      72                  if ok:
      73                      linkname = os.path.join(os.pardir,
      74                                              linkname)
      75                      linknames(oldname, newname, linkname)
      76              else:
      77                  os.symlink(linkname, newname)
      78  
      79  if __name__ == '__main__':
      80      sys.exit(main())