Python style changes

This tries to conform more closely to PEP8. Imports have been checked and,
if used only once, moved closer to the use to avoid potential import
loops. This also includes a few other minor changes, like using __main__
for utility scripts and variable renames to avoid name clashes.

13 files changed, 104 insertions, 106 deletions

diff --git a/pynslcd/cache.py b/pynslcd/cache.py
index ce706be..7089d41 100644
--- a/pynslcd/cache.py
+++ b/pynslcd/cache.py
@@ -1,7 +1,7 @@
 
 # cache.py - caching layer for pynslcd
 #
-# Copyright (C) 2012 Arthur de Jong
+# Copyright (C) 2012, 2013 Arthur de Jong
 #
 # This library is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Lesser General Public
@@ -29,8 +29,6 @@ import sqlite3
 # TODO: probably create a config table
 
 
-
-
 # FIXME: store the cache in the right place and make it configurable
 filename = '/tmp/cache.sqlite'
 dirname = os.path.dirname(filename)
diff --git a/pynslcd/cfg.py b/pynslcd/cfg.py
index baa29ec..a9f1d89 100644
--- a/pynslcd/cfg.py
+++ b/pynslcd/cfg.py
@@ -20,12 +20,9 @@
 
 import logging
 import re
-import sys
 
 import ldap
 
-from expr import Expression
-
 
 # the number of threads to start
 threads = 5
@@ -134,6 +131,7 @@ def _get_maps():
     # separate function as not to pollute the namespace and avoid import loops
     import alias, ether, group, host, netgroup, network, passwd
     import protocol, rpc, service, shadow
+    import sys
     return dict(
             alias=alias, aliases=alias,
             ether=ether, ethers=ether,
@@ -274,6 +272,7 @@ def read(filename):
         # pam_authz_search <FILTER>
         m = re.match('pam_authz_search\s+(?P<value>\S.*)', line, re.IGNORECASE)
         if m:
+            from expr import Expression
             pam_authz_searches.append(Expression(m.group('value')))
             # TODO: check pam_authz_search expression to only contain
             # username, service, ruser, rhost, tty, hostname, fqdn, dn or
diff --git a/pynslcd/group.py b/pynslcd/group.py
index 71a1173..a72c57d 100644
--- a/pynslcd/group.py
+++ b/pynslcd/group.py
@@ -65,9 +65,11 @@ class Search(search.LDAPSearch):
             memberuid = self.parameters['memberUid']
             dn = uid2dn(self.conn, memberuid)
             if dn:
-                return '(&%s(|(%s=%s)(%s=%s)))' % (self.filter,
-                          attmap['memberUid'], escape_filter_chars(memberuid),
-                          attmap['member'], escape_filter_chars(dn))
+                return '(&%s(|(%s=%s)(%s=%s)))' % (
+                        self.filter,
+                        attmap['memberUid'], escape_filter_chars(memberuid),
+                        attmap['member'], escape_filter_chars(dn)
+                    )
         return super(Search, self).mk_filter()
 
 
diff --git a/pynslcd/nscd.py b/pynslcd/nscd.py
index 19e5ceb..e71bd04 100644
--- a/pynslcd/nscd.py
+++ b/pynslcd/nscd.py
@@ -22,7 +22,6 @@ import fcntl
 import logging
 import os
 import subprocess
-import struct
 
 import cfg
 
@@ -74,9 +73,8 @@ def loop(fd):
     os.environ['PATH'] = '/usr/sbin:/usr/bin:/sbin:/bin'
     while True:
         db = os.read(fd, 1)
-        # FIXME: define the characters and maps somewhere
         if db == '':
-            break
+            break  # close process down
         db = _char_to_db.get(db, None)
         if db:
             exec_invalidate(db)
diff --git a/pynslcd/pynslcd.py b/pynslcd/pynslcd.py
index 35ecb08..99bfda8 100755
--- a/pynslcd/pynslcd.py
+++ b/pynslcd/pynslcd.py
@@ -73,8 +73,8 @@ class MySysLogHandler(logging.Handler):
     def emit(self, record):
         priority = self.mapping.get(record.levelno, syslog.LOG_WARNING)
         msg = self.format(record)
-        for l in msg.splitlines():
-            syslog.syslog(priority, l)
+        for line in msg.splitlines():
+            syslog.syslog(priority, line)
 
 
 # configure logging
@@ -113,8 +113,9 @@ def parse_cmdline():
     global program_name
     program_name = sys.argv[0] or program_name
     try:
-        optlist, args = getopt.gnu_getopt(sys.argv[1:],
-          'cdhV', ('check', 'debug', 'help', 'version', ))
+        optlist, args = getopt.gnu_getopt(
+            sys.argv[1:], 'cdhV',
+            ('check', 'debug', 'help', 'version'))
         for flag, arg in optlist:
             if flag in ('-c', '--check'):
                 global checkonly
@@ -131,10 +132,12 @@ def parse_cmdline():
         if len(args):
             raise getopt.GetoptError('unrecognized option \'%s\'' % args[0], args[0])
     except getopt.GetoptError, reason:
-        sys.stderr.write("%(program_name)s: %(reason)s\n"
-                         "Try '%(program_name)s --help' for more information.\n"
-                          % {'program_name': program_name,
-                             'reason': reason, })
+        sys.stderr.write(
+            "%(program_name)s: %(reason)s\n"
+            "Try '%(program_name)s --help' for more information.\n" % {
+                'program_name': program_name,
+                'reason': reason,
+            })
         sys.exit(1)
 
 
@@ -168,7 +171,7 @@ def getpeercred(fd):
     """Return uid, gid and pid of calling application."""
     import struct
     import socket
-    SO_PEERCRED = 17
+    SO_PEERCRED = getattr(socket, 'SO_PEERCRED', 17)
     creds = fd.getsockopt(socket.SOL_SOCKET, SO_PEERCRED, struct.calcsize('3i'))
     pid, uid, gid = struct.unpack('3i', creds)
     return uid, gid, pid
@@ -181,12 +184,12 @@ handlers.update(common.get_handlers('group'))
 handlers.update(common.get_handlers('host'))
 handlers.update(common.get_handlers('netgroup'))
 handlers.update(common.get_handlers('network'))
-handlers.update(common.get_handlers('pam'))
 handlers.update(common.get_handlers('passwd'))
 handlers.update(common.get_handlers('protocol'))
 handlers.update(common.get_handlers('rpc'))
 handlers.update(common.get_handlers('service'))
 handlers.update(common.get_handlers('shadow'))
+handlers.update(common.get_handlers('pam'))
 handlers.update(common.get_handlers('usermod'))
 
 
@@ -196,8 +199,7 @@ def acceptconnection(session):
     # See: http://docs.python.org/library/socket.html#socket.socket.settimeout
     fp = None
     try:
-        # probably use finally
-        # indicate new connection to logging module (genrates unique id)
+        # indicate new connection to logging module (generates unique id)
         log_newsession()
         # log connection
         try:
@@ -292,9 +294,9 @@ if __name__ == '__main__':
         sys.exit(1)
     # daemonize
     if debugging:
-        daemon = pidfile
+        ctx = pidfile
     else:
-        daemon = daemon.DaemonContext(
+        ctx = daemon.DaemonContext(
                       pidfile=pidfile,
                       signal_map={
                           signal.SIGTERM: 'terminate',
@@ -302,7 +304,7 @@ if __name__ == '__main__':
                           signal.SIGPIPE: None,
                       })
     # start daemon
-    with daemon:
+    with ctx:
         try:
             # start normal logging as configured
             if not debugging:
diff --git a/pynslcd/search.py b/pynslcd/search.py
index 219929b..3db6e9d 100644
--- a/pynslcd/search.py
+++ b/pynslcd/search.py
@@ -25,7 +25,6 @@ import ldap
 import ldap.ldapobject
 
 import cfg
-import nscd
 
 
 # global indicator that there was some error connection to an LDAP server
@@ -56,6 +55,7 @@ class Connection(ldap.ldapobject.ReconnectLDAPObject):
             self.set_option(ldap.OPT_X_TLS, ldap.OPT_X_TLS_HARD)
 
     def reconnect_after_fail(self):
+        import nscd
         logging.info('connected to LDAP server %s', cfg.uri)
         nscd.invalidate()
 
diff --git a/pynslcd/shadow.py b/pynslcd/shadow.py
index 6f7df10..bedac50 100644
--- a/pynslcd/shadow.py
+++ b/pynslcd/shadow.py
@@ -95,7 +95,7 @@ class ShadowRequest(common.Request):
         # return results
         for name in names:
             yield (name, passwd, lastchangedate, mindays, maxdays, warndays,
-                    inactdays, expiredate, flag)
+                   inactdays, expiredate, flag)
 
 
 class ShadowByNameRequest(ShadowRequest):
diff --git a/pynslcd/tio.py b/pynslcd/tio.py
index 9e7f99b..02b7ec6 100644
--- a/pynslcd/tio.py
+++ b/pynslcd/tio.py
@@ -1,7 +1,7 @@
 
 # tio.py - I/O functions
 #
-# Copyright (C) 2010, 2011 Arthur de Jong
+# Copyright (C) 2010, 2011, 2012, 2013 Arthur de Jong
 #
 # This library is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Lesser General Public
@@ -51,10 +51,10 @@ class TIOStream(object):
         return _int32.unpack(self.read(_int32.size))[0]
 
     def read_string(self, maxsize=None):
-        len = self.read_int32()
-        if maxsize and len >= maxsize:
+        num = self.read_int32()
+        if maxsize and num >= maxsize:
             raise TIOStreamError()
-        return self.read(len)
+        return self.read(num)
 
     def read_address(self):
         """Read an address (usually IPv4 or IPv6) from the stream and return
diff --git a/pynslcd/usermod.py b/pynslcd/usermod.py
index c957b97..9622fb2 100644
--- a/pynslcd/usermod.py
+++ b/pynslcd/usermod.py
@@ -26,9 +26,7 @@ import os.path
 
 import ldap
 
-import cache
 import cfg
-import common
 import constants
 import pam
 import passwd
@@ -94,10 +92,10 @@ class UserModRequest(pam.PAMRequest):
                 mods.append((ldap.MOD_REPLACE, passwd.attmap['homeDirectory'], [homedir]))
             elif not os.path.isabs(homedir):
                 self.write_result(constants.NSLCD_USERMOD_HOMEDIR,
-                    'should be an absolute path')
+                                  'should be an absolute path')
             elif not os.path.isdir(homedir):
                 self.write_result(constants.NSLCD_USERMOD_HOMEDIR,
-                    'not a directory')
+                                  'not a directory')
             else:
                 mods.append((ldap.MOD_REPLACE, passwd.attmap['homeDirectory'], [homedir]))
         # check login shell modification
@@ -107,10 +105,10 @@ class UserModRequest(pam.PAMRequest):
                 mods.append((ldap.MOD_REPLACE, passwd.attmap['loginShell'], [shell]))
             elif shell not in list_shells():
                 self.write_result(constants.NSLCD_USERMOD_SHELL,
-                    'unlisted shell')
+                                  'unlisted shell')
             elif not os.path.isfile(shell) or not os.access(shell, os.X_OK):
                 self.write_result(constants.NSLCD_USERMOD_SHELL,
-                    'not an executable')
+                                  'not an executable')
             else:
                 mods.append((ldap.MOD_REPLACE, passwd.attmap['loginShell'], [shell]))
         # get a connection and perform the modification
diff --git a/utils/chsh.py b/utils/chsh.py
index 30c5c12..2f81f13 100755
--- a/utils/chsh.py
+++ b/utils/chsh.py
@@ -31,14 +31,13 @@ import users
 
 # set up command line parser
 parser = argparse.ArgumentParser(
-        description='Change the user login shell in LDAP.',
-        epilog='Report bugs to <%s>.' % constants.PACKAGE_BUGREPORT
-    )
+    description='Change the user login shell in LDAP.',
+    epilog='Report bugs to <%s>.' % constants.PACKAGE_BUGREPORT)
 parser.add_argument('-V', '--version', action=VersionAction)
 parser.add_argument('-s', '--shell', help='login shell for the user account')
 parser.add_argument('-l', '--list-shells', action=ListShellsAction)
 parser.add_argument('username', metavar='USER', nargs='?',
-    help="the user who's shell to change")
+                    help="the user who's shell to change")
 
 
 def ask_shell(oldshell):
@@ -47,24 +46,26 @@ def ask_shell(oldshell):
     return shell or oldshell
 
 
-# parse arguments
-args = parser.parse_args()
-# check username part
-user = users.User(args.username)
-user.check()
-# check the command line shell if one was provided (to fail early)
-shell = args.shell
-if shell is not None:
-    shells.check(shell, user.asroot)
-# prompt for a password if required
-password = user.get_passwd()
-# prompt for a shell if it was not specified on the command line
-if shell is None:
-    print 'Enter the new value, or press ENTER for the default'
-    shell = ask_shell(user.shell)
-    shells.check(shell, user.asroot)
-# perform the modification
-result = nslcd.usermod(user.username, user.asroot, password, {
-        constants.NSLCD_USERMOD_SHELL: shell,
-    })
-# TODO: print proper response
+if __name__ == '__main__':
+    # parse arguments
+    args = parser.parse_args()
+    # check username part
+    user = users.User(args.username)
+    user.check()
+    # check the command line shell if one was provided (to fail early)
+    shell = args.shell
+    if shell is not None:
+        shells.check(shell, user.asroot)
+    # prompt for a password if required
+    password = user.get_passwd()
+    # prompt for a shell if it was not specified on the command line
+    if shell is None:
+        print 'Enter the new value, or press ENTER for the default'
+        shell = ask_shell(user.shell)
+        shells.check(shell, user.asroot)
+    # perform the modification
+    result = nslcd.usermod(
+        user.username, user.asroot, password, {
+            constants.NSLCD_USERMOD_SHELL: shell,
+        })
+    # TODO: print proper response
diff --git a/utils/getent.py b/utils/getent.py
index 07cc670..d662272 100755
--- a/utils/getent.py
+++ b/utils/getent.py
@@ -33,14 +33,13 @@ from nslcd import NslcdClient
 
 # set up command line parser
 parser = argparse.ArgumentParser(
-        description='Query information in LDAP.',
-        epilog='Report bugs to <%s>.' % constants.PACKAGE_BUGREPORT
-    )
+    description='Query information in LDAP.',
+    epilog='Report bugs to <%s>.' % constants.PACKAGE_BUGREPORT)
 parser.add_argument('-V', '--version', action=VersionAction)
 parser.add_argument('database', metavar='DATABASE',
-    help='any of those supported by nslcd')
+                    help='any of those supported by nslcd')
 parser.add_argument('key', metavar='KEY', nargs='?',
-    help='information to lookup')
+                    help='information to lookup')
 
 
 def getent_aliases(database, key=None):
@@ -312,32 +311,33 @@ def getent_shadow(database, key=None):
             )
 
 
-args = parser.parse_args()
-try:
-    if args.database == 'aliases':
-        getent_aliases(args.database, args.key)
-    elif args.database == 'ethers':
-        getent_ethers(args.database, args.key)
-    elif args.database in ('group', 'group.bymember'):
-        getent_group(args.database, args.key)
-    elif args.database in ('hosts', 'hostsv4', 'hostsv6'):
-        getent_hosts(args.database, args.key)
-    elif args.database in ('netgroup', 'netgroup.norec'):
-        getent_netgroup(args.database, args.key)
-    elif args.database in ('networks', 'networksv4', 'networksv6'):
-        getent_networks(args.database, args.key)
-    elif args.database == 'passwd':
-        getent_passwd(args.database, args.key)
-    elif args.database == 'protocols':
-        getent_protocols(args.database, args.key)
-    elif args.database == 'rpc':
-        getent_rpc(args.database, args.key)
-    elif args.database == 'services':
-        getent_services(args.database, args.key)
-    elif args.database == 'shadow':
-        getent_shadow(args.database, args.key)
-    else:
-        parser.error('Unknown database: %s' % args.database)
-except struct.error:
-    print 'Problem contacting nslcd'
-    sys.exit(1)
+if __name__ == '__main__':
+    args = parser.parse_args()
+    try:
+        if args.database == 'aliases':
+            getent_aliases(args.database, args.key)
+        elif args.database == 'ethers':
+            getent_ethers(args.database, args.key)
+        elif args.database in ('group', 'group.bymember'):
+            getent_group(args.database, args.key)
+        elif args.database in ('hosts', 'hostsv4', 'hostsv6'):
+            getent_hosts(args.database, args.key)
+        elif args.database in ('netgroup', 'netgroup.norec'):
+            getent_netgroup(args.database, args.key)
+        elif args.database in ('networks', 'networksv4', 'networksv6'):
+            getent_networks(args.database, args.key)
+        elif args.database == 'passwd':
+            getent_passwd(args.database, args.key)
+        elif args.database == 'protocols':
+            getent_protocols(args.database, args.key)
+        elif args.database == 'rpc':
+            getent_rpc(args.database, args.key)
+        elif args.database == 'services':
+            getent_services(args.database, args.key)
+        elif args.database == 'shadow':
+            getent_shadow(args.database, args.key)
+        else:
+            parser.error('Unknown database: %s' % args.database)
+    except struct.error:
+        print 'Problem contacting nslcd'
+        sys.exit(1)
diff --git a/utils/nslcd.py b/utils/nslcd.py
index 389b194..031319c 100644
--- a/utils/nslcd.py
+++ b/utils/nslcd.py
@@ -71,12 +71,12 @@ class NslcdClient(object):
         return _int32.unpack(self.read(_int32.size))[0]
 
     def read_string(self):
-        len = self.read_int32()
-        return self.read(len)
+        num = self.read_int32()
+        return self.read(num)
 
     def read_stringlist(self):
-        len = self.read_int32()
-        return [self.read_string() for x in xrange(len)]
+        num = self.read_int32()
+        return [self.read_string() for x in xrange(num)]
 
     def read_ether(self):
         value = self.fp.read(6)
@@ -87,8 +87,8 @@ class NslcdClient(object):
         return af, socket.inet_ntop(af, self.read_string())
 
     def read_addresslist(self):
-        len = self.read_int32()
-        return [self.read_address() for x in xrange(len)]
+        num = self.read_int32()
+        return [self.read_address() for x in xrange(num)]
 
     def get_response(self):
         # complete the request if required and check response header
diff --git a/utils/users.py b/utils/users.py
index 02216d6..3387318 100644
--- a/utils/users.py
+++ b/utils/users.py
@@ -34,8 +34,8 @@ class User(object):
         else:
             self.asroot = False
             userinfo = pwd.getpwuid(self.myuid)
-        (self.username, ignore, self.uid, self.gid, self.gecos, self.homedir,
-            self.shell) = userinfo
+        (self.username, self.password, self.uid, self.gid, self.gecos,
+            self.homedir, self.shell) = userinfo
         # if we are trying to modify another user we should be root
         self.asroot = self.myuid != self.uid