Load two /etc/passwd files and find all users and groups that need to be fixed on a machine.

fix-uid-gid.py

#!/usr/bin/python

import sys

def load_passwd(path):
  lookup = { }
  f = file(path)

  for line in f:
    line = line.rstrip()
    fields = line.split(':')

#!/usr/bin/python

import sys

def load_passwd(path):
  lookup = { }
  f = file(path)

  for line in f:
    line = line.rstrip()
    fields = line.split(':')

    lookup[fields[0]] = { 'uid': fields[2], 'gid': fields[3] }

  f.close()

  return lookup

if __name__ == '__main__':

  if len(sys.argv) != 3:
    print "Usage: %s <current passwd> <new passwd>" % (sys.argv[0])
    sys.exit(1)

  current_passwd = load_passwd(sys.argv[1])
  new_passwd = load_passwd(sys.argv[2])

  for user in new_passwd.keys():

    if current_passwd.has_key(user):
      current = current_passwd[user]
      new = new_passwd[user]

      if current['uid'] != new['uid'] or current['gid'] != new['gid']:
        print "Need to change %s (uid:%s gid:%s) -> (uid:%s gid:%s)" % \
          (user, current['uid'], current['gid'], new['uid'], new['gid'])
        print "  find / \( -uid %s -exec chown %s \{\} \; \) -o \( -gid %s -exec chgrp %s \{\} \; \)" % \
          (current['uid'], new['uid'], current['gid'], new['gid'])
    else:
      print "Need to add %s (uid:%s gid:%s)" % (user, new['uid'], new['gid'])