rdiff

#!/usr/bin/env python
# vim: shiftwidth=4 expandtab ft=python
# Written by Ben Samuel, 2010. Released into public domain.
# Use at your own risk.

import os, sys, stat
import os.path as path

def statOrNone(ent):
    try:
        return os.lstat(ent)
    except:
        return None
def tryListing(path):
    try:
        return os.listdir(path)
    except:
        return []

queue = [tuple(sys.argv[1:3])]
while queue:
    (this, that) = queue.pop(0)
    (this_stat, that_stat) = map(statOrNone, (this, that))
    if this_stat is None and that_stat is None:
        print "Same: %s and %s are missing" % (this, that)
        continue
    if this_stat is None and that_stat is not None:
        print "That: %s is missing, but %s exists" % (this, that)
        continue
    if this_stat is not None and that_stat is None:
        print "This: %s exists, but %s is missing" % (this, that)
        continue
    if this_stat[stat.ST_INO] == that_stat[stat.ST_INO] \
        and this_stat[stat.ST_DEV] == that_stat[stat.ST_DEV]:
        continue
    (this_mode, that_mode) = (this_stat[stat.ST_MODE], that_stat[stat.ST_MODE])
    (this_dir, that_dir) = map(stat.S_ISDIR, (this_mode, that_mode))
    if this_dir and that_dir:
        # Reading it backwards:
        # Read in the directory listings of this and that, join them together
        # Step through the combined listing (for ent in)
        # With each item, make a pair object of this/ent and that/ent
        # Create a set of those entries to remove duplicates
        # Extend the queue with the contents of that set
        queue.extend(set(((path.join(this, ent), path.join(that, ent))
            for ent in tryListing(this) + tryListing(that))))
        continue
    if this_dir != that_dir:
        print "%s is %sa directory but %s is %sa directory" % (
                this, '' if this_dir else 'not',
                that, '' if that_dir else 'not')