1  #! /usr/bin/env python3
       2  
       3  # findlinksto
       4  #
       5  # find symbolic links to a path matching a regular expression
       6  
       7  import os
       8  import sys
       9  import re
      10  import getopt
      11  
      12  def main():
      13      try:
      14          opts, args = getopt.getopt(sys.argv[1:], '')
      15          if len(args) < 2:
      16              raise getopt.GetoptError('not enough arguments', None)
      17      except getopt.GetoptError as msg:
      18          sys.stdout = sys.stderr
      19          print(msg)
      20          print('usage: findlinksto pattern directory ...')
      21          sys.exit(2)
      22      pat, dirs = args[0], args[1:]
      23      prog = re.compile(pat)
      24      for dirname in dirs:
      25          os.walk(dirname, visit, prog)
      26  
      27  def visit(prog, dirname, names):
      28      if os.path.islink(dirname):
      29          names[:] = []
      30          return
      31      if os.path.ismount(dirname):
      32          print('descend into', dirname)
      33      for name in names:
      34          name = os.path.join(dirname, name)
      35          try:
      36              linkto = os.readlink(name)
      37              if prog.search(linkto) is not None:
      38                  print(name, '->', linkto)
      39          except OSError:
      40              pass
      41  
      42  if __name__ == '__main__':
      43      main()