#!/usr/bin/env python

"""Recursively find symbolic link loops in specified directory tree"""

from optparse import OptionParser
import errno
import sys
import os

__license__ = 'BSD'

def main(argv=None):
    optparse = OptionParser('%prog <dir>', description=__doc__)
    args = optparse.parse_args(argv)[1]
    if len(args) != 1:
        optparse.print_help()
        return 2
    for basedir, subdirs, filenames in os.walk(args[0]):
        for filename in filenames:
            path = os.path.join(basedir, filename)
            if os.path.islink(path):
                try:
                    os.stat(path)
                except (OSError, IOError), error:
                    if error.errno == errno.ELOOP:
                        print >> sys.stderr, 'ELOOP: %s <-> %s' % (
                                path, os.path.join(basedir, os.readlink(path)))

    return 0

if __name__ == '__main__':
    sys.exit(main())