Add local cliapp module

Add a copy of the specific version of the cliapp module required by morph, a
known version of which can't otherwise be guaranteed to be available on
general Linux systems, or via PyPi. Including the module directly allows for
continued development in line with morph, until a time when it may become
desirable to move away from dependence on this module.

With a local copy of cliapp added to morph, it has been shown that morph is
capable of building Baserock images without depending on an existing Baserock
system.

Change-Id: Iab1f7037c7afff054a2404c0552d9b5e4d2d141f

18 files changed, 3730 insertions, 0 deletions

diff --git a/cliapp/__init__.py b/cliapp/__init__.py
new file mode 100644
index 00000000..6e4d4081
--- /dev/null
+++ b/cliapp/__init__.py
@@ -0,0 +1,34 @@
+# Copyright (C) 2011  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+__version__ = '1.20130808'
+
+
+from fmt import TextFormat
+from settings import (Settings, log_group_name, config_group_name,
+                      perf_group_name)
+from runcmd import runcmd, runcmd_unchecked, shell_quote, ssh_runcmd
+from app import Application, AppException
+
+# The plugin system
+from hook import Hook, FilterHook
+from hookmgr import HookManager
+from plugin import Plugin
+from pluginmgr import PluginManager
+
+
+__all__ = locals()
diff --git a/cliapp/app.py b/cliapp/app.py
new file mode 100644
index 00000000..8e280afa
--- /dev/null
+++ b/cliapp/app.py
@@ -0,0 +1,671 @@
+# Copyright (C) 2011  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import errno
+import gc
+import inspect
+import logging
+import logging.handlers
+import os
+import StringIO
+import sys
+import traceback
+import time
+import platform
+import textwrap
+
+import cliapp
+
+
+class AppException(Exception):
+
+    '''Base class for application specific exceptions.
+
+    Any exceptions that are subclasses of this one get printed as
+    nice errors to the user. Any other exceptions cause a Python
+    stack trace to be written to stderr.
+
+    '''
+
+    def __init__(self, msg):
+        self.msg = msg
+
+    def __str__(self):
+        return self.msg
+
+
+class LogHandler(logging.handlers.RotatingFileHandler): # pragma: no cover
+
+    '''Like RotatingFileHandler, but set permissions of new files.'''
+
+    def __init__(self, filename, perms=0600, *args, **kwargs):
+        self._perms = perms
+        logging.handlers.RotatingFileHandler.__init__(self, filename,
+                                                      *args, **kwargs)
+
+    def _open(self):
+        if not os.path.exists(self.baseFilename):
+            flags = os.O_CREAT | os.O_WRONLY
+            fd = os.open(self.baseFilename, flags, self._perms)
+            os.close(fd)
+        return logging.handlers.RotatingFileHandler._open(self)
+
+
+class Application(object):
+
+    '''A framework for Unix-like command line programs.
+
+    The user should subclass this base class for each application.
+    The subclass does not need code for the mundane, boilerplate
+    parts that are the same in every utility, and can concentrate on the
+    interesting part that is unique to it.
+
+    To start the application, call the `run` method.
+
+    The ``progname`` argument sets tne name of the program, which is
+    used for various purposes, such as determining the name of the
+    configuration file.
+
+    Similarly, ``version`` sets the version number of the program.
+
+    ``description`` and ``epilog`` are included in the output of
+    ``--help``. They are formatted to fit the screen. Unlike the
+    default behavior of ``optparse``, empty lines separate
+    paragraphs.
+
+    '''
+
+    def __init__(self, progname=None, version='0.0.0', description=None,
+                 epilog=None):
+        self.fileno = 0
+        self.global_lineno = 0
+        self.lineno = 0
+        self._description = description
+        if not hasattr(self, 'arg_synopsis'):
+            self.arg_synopsis = '[FILE]...'
+        if not hasattr(self, 'cmd_synopsis'):
+            self.cmd_synopsis = {}
+
+        self.subcommands = {}
+        self.subcommand_aliases = {}
+        self.hidden_subcommands = set()
+        for method_name in self._subcommand_methodnames():
+            cmd = self._unnormalize_cmd(method_name)
+            self.subcommands[cmd] = getattr(self, method_name)
+
+        self.settings = cliapp.Settings(progname, version,
+                                        usage=self._format_usage,
+                                        description=self._format_description,
+                                        epilog=epilog)
+
+        self.plugin_subdir = 'plugins'
+
+        # For meliae memory dumps.
+        self.memory_dump_counter = 0
+        self.last_memory_dump = 0
+
+        # For process duration.
+        self._started = os.times()[-1]
+
+    def add_settings(self):
+        '''Add application specific settings.'''
+
+    def run(self, args=None, stderr=sys.stderr, sysargv=sys.argv,
+            log=logging.critical):
+        '''Run the application.'''
+
+        def run_it():
+            self._run(args=args, stderr=stderr, log=log)
+
+        if self.settings.progname is None and sysargv:
+            self.settings.progname = os.path.basename(sysargv[0])
+        envname = '%s_PROFILE' % self._envname(self.settings.progname)
+        profname = os.environ.get(envname, '')
+        if profname: # pragma: no cover
+            import cProfile
+            cProfile.runctx('run_it()', globals(), locals(), profname)
+        else:
+            run_it()
+
+    def _envname(self, progname):
+        '''Create an environment variable name of the name of a program.'''
+
+        basename = os.path.basename(progname)
+        if '.' in basename:
+            basename = basename.split('.')[0]
+
+        ok = 'abcdefghijklmnopqrstuvwxyz0123456789'
+        ok += ok.upper()
+
+        return ''.join(x.upper() if x in ok else '_' for x in basename)
+
+    def _set_process_name(self): # pragma: no cover
+        comm = '/proc/self/comm'
+        if platform.system() == 'Linux' and os.path.exists(comm):
+            with open('/proc/self/comm', 'w', 0) as f:
+                f.write(self.settings.progname[:15])
+
+    def _run(self, args=None, stderr=sys.stderr, log=logging.critical):
+        try:
+            self._set_process_name()
+            self.add_settings()
+            self.setup_plugin_manager()
+
+            # A little bit of trickery here to make --no-default-configs and
+            # --config=foo work right: we first parse the command line once,
+            # and pick up any config files. Then we read configs. Finally,
+            # we re-parse the command line to allow any options to override
+            # config file settings.
+            self.setup()
+            self.enable_plugins()
+            if self.subcommands:
+                self.add_default_subcommands()
+            args = sys.argv[1:] if args is None else args
+            self.parse_args(args, configs_only=True)
+            self.settings.load_configs()
+            args = self.parse_args(args)
+
+            self.setup_logging()
+            self.log_config()
+
+            if self.settings['output']:
+                self.output = open(self.settings['output'], 'w')
+            else:
+                self.output = sys.stdout
+
+            self.process_args(args)
+            self.cleanup()
+            self.disable_plugins()
+        except AppException, e:
+            log(traceback.format_exc())
+            stderr.write('ERROR: %s\n' % str(e))
+            sys.exit(1)
+        except SystemExit, e:
+            if e.code is not None and type(e.code) != int:
+                log(str(e))
+                stderr.write('ERROR: %s\n' % str(e))
+            sys.exit(e.code if type(e.code) == int else 1)
+        except KeyboardInterrupt, e:
+            sys.exit(255)
+        except IOError, e: # pragma: no cover
+            if e.errno == errno.EPIPE and e.filename is None:
+                # We're writing to stdout, and it broke. This almost always
+                # happens when we're being piped to less, and the user quits
+                # less before we finish writing everything out. So we ignore
+                # the error in that case.
+                sys.exit(1)
+            log(traceback.format_exc())
+            stderr.write('ERROR: %s\n' % str(e))
+            sys.exit(1)
+        except OSError, e: # pragma: no cover
+            log(traceback.format_exc())
+            if hasattr(e, 'filename') and e.filename:
+                stderr.write('ERROR: %s: %s\n' % (e.filename, e.strerror))
+            else:
+                stderr.write('ERROR: %s\n' % e.strerror)
+            sys.exit(1)
+        except BaseException, e: # pragma: no cover
+            log(traceback.format_exc())
+            stderr.write(traceback.format_exc())
+            sys.exit(1)
+
+        logging.info('%s version %s ends normally' %
+                     (self.settings.progname, self.settings.version))
+
+    def compute_setting_values(self, settings):
+        '''Compute setting values after configs and options are parsed.
+
+        You can override this method to implement a default value for
+        a setting that is dependent on another setting. For example,
+        you might have settings "url" and "protocol", where protocol
+        gets set based on the schema of the url, unless explicitly
+        set by the user. So if the user sets just the url, to
+        "http://www.example.com/", the protocol would be set to
+        "http". If the user sets both url and protocol, the protocol
+        does not get modified by compute_setting_values.
+
+        '''
+
+    def add_subcommand(
+        self, name, func, arg_synopsis=None, aliases=None, hidden=False):
+        '''Add a subcommand.
+
+        Normally, subcommands are defined by add ``cmd_foo`` methods
+        to the application class. However, sometimes it is more convenient
+        to have them elsewhere (e.g., in plugins). This method allows
+        doing that.
+
+        The callback function must accept a list of command line
+        non-option arguments.
+
+        '''
+
+        if name not in self.subcommands:
+            self.subcommands[name] = func
+            self.cmd_synopsis[name] = arg_synopsis
+            self.subcommand_aliases[name] = aliases or []
+            if hidden: # pragma: no cover
+                self.hidden_subcommands.add(name)
+
+    def add_default_subcommands(self):
+        if 'help' not in self.subcommands:
+            self.add_subcommand('help', self.help)
+        if 'help-all' not in self.subcommands:
+            self.add_subcommand('help-all', self.help_all)
+
+    def _help_helper(self, args, show_all): # pragma: no cover
+        try:
+            width = int(os.environ.get('COLUMNS', '78'))
+        except ValueError:
+            width = 78
+
+        fmt = cliapp.TextFormat(width=width)
+
+        if args:
+            usage = self._format_usage_for(args[0])
+            description = fmt.format(self._format_subcommand_help(args[0]))
+            text = '%s\n\n%s' % (usage, description)
+        else:
+            usage = self._format_usage(all=show_all)
+            description = fmt.format(self._format_description(all=show_all))
+            text = '%s\n\n%s' % (usage, description)
+
+        text = self.settings.progname.join(text.split('%prog'))
+        self.output.write(text)
+
+    def help(self, args): # pragma: no cover
+        '''Print help.'''
+        self._help_helper(args, False)
+
+    def help_all(self, args): # pragma: no cover
+        '''Print help, including hidden subcommands.'''
+        self._help_helper(args, True)
+
+    def _subcommand_methodnames(self):
+        return [x
+                 for x in dir(self)
+                 if x.startswith('cmd_') and
+                    inspect.ismethod(getattr(self, x))]
+
+    def _normalize_cmd(self, cmd):
+        return 'cmd_%s' % cmd.replace('-', '_')
+
+    def _unnormalize_cmd(self, method):
+        assert method.startswith('cmd_')
+        return method[len('cmd_'):].replace('_', '-')
+
+    def _format_usage(self, all=False):
+        '''Format usage, possibly also subcommands, if any.'''
+        if self.subcommands:
+            lines = []
+            prefix = 'Usage:'
+            for cmd in sorted(self.subcommands.keys()):
+                if all or cmd not in self.hidden_subcommands:
+                    args = self.cmd_synopsis.get(cmd, '') or ''
+                    lines.append(
+                        '%s %%prog [options] %s %s' % (prefix, cmd, args))
+                    prefix = ' ' * len(prefix)
+            return '\n'.join(lines)
+        else:
+            return None
+
+    def _format_usage_for(self, cmd): # pragma: no cover
+        args = self.cmd_synopsis.get(cmd, '') or ''
+        return 'Usage: %%prog [options] %s %s' % (cmd, args)
+
+    def _format_description(self, all=False):
+        '''Format OptionParser description, with subcommand support.'''
+        if self.subcommands:
+            summaries = []
+            for cmd in sorted(self.subcommands.keys()):
+                if all or cmd not in self.hidden_subcommands:
+                    summaries.append(self._format_subcommand_summary(cmd))
+            cmd_desc = ''.join(summaries)
+            return '%s\n%s' % (self._description or '', cmd_desc)
+        else:
+            return self._description
+
+    def _format_subcommand_summary(self, cmd): # pragma: no cover
+        method = self.subcommands[cmd]
+        doc = method.__doc__ or ''
+        lines = doc.splitlines()
+        if lines:
+            summary = lines[0].strip()
+        else:
+            summary = ''
+        return '* %%prog %s: %s\n' % (cmd, summary)
+
+    def _format_subcommand_help(self, cmd): # pragma: no cover
+        if cmd not in self.subcommands:
+            raise cliapp.AppException('Unknown subcommand %s' % cmd)
+        method = self.subcommands[cmd]
+        doc = method.__doc__ or ''
+        t = doc.split('\n', 1)
+        if len(t) == 1:
+            return doc
+        else:
+            first, rest = t
+            return first + '\n' + textwrap.dedent(rest)
+
+    def setup_logging(self): # pragma: no cover
+        '''Set up logging.'''
+
+        level_name = self.settings['log-level']
+        levels = {
+            'debug': logging.DEBUG,
+            'info': logging.INFO,
+            'warning': logging.WARNING,
+            'error': logging.ERROR,
+            'critical': logging.CRITICAL,
+            'fatal': logging.FATAL,
+        }
+        level = levels.get(level_name, logging.INFO)
+
+        if self.settings['log'] == 'syslog':
+            handler = self.setup_logging_handler_for_syslog()
+        elif self.settings['log'] and self.settings['log'] != 'none':
+            handler = LogHandler(
+                            self.settings['log'],
+                            perms=int(self.settings['log-mode'], 8),
+                            maxBytes=self.settings['log-max'],
+                            backupCount=self.settings['log-keep'],
+                            delay=False)
+            fmt = '%(asctime)s %(levelname)s %(message)s'
+            datefmt = '%Y-%m-%d %H:%M:%S'
+            formatter = logging.Formatter(fmt, datefmt)
+            handler.setFormatter(formatter)
+        else:
+            handler = self.setup_logging_handler_to_none()
+            # reduce amount of pointless I/O
+            level = logging.FATAL
+
+        logger = logging.getLogger()
+        logger.addHandler(handler)
+        logger.setLevel(level)
+
+    def setup_logging_handler_for_syslog(self): # pragma: no cover
+        '''Setup a logging.Handler for logging to syslog.'''
+
+        handler = logging.handlers.SysLogHandler(address='/dev/log')
+        progname = '%%'.join(self.settings.progname.split('%'))
+        fmt = progname + ": %(levelname)s %(message)s"
+        formatter = logging.Formatter(fmt)
+        handler.setFormatter(formatter)
+
+        return handler
+
+    def setup_logging_handler_to_none(self): # pragma: no cover
+        '''Setup a logging.Handler that does not log anything anywhere.'''
+
+        handler = logging.FileHandler('/dev/null')
+        return handler
+
+    def setup_logging_handler_to_file(self): # pragma: no cover
+        '''Setup a logging.Handler for logging to a named file.'''
+
+        handler = LogHandler(
+                        self.settings['log'],
+                        perms=int(self.settings['log-mode'], 8),
+                        maxBytes=self.settings['log-max'],
+                        backupCount=self.settings['log-keep'],
+                        delay=False)
+        fmt = self.setup_logging_format()
+        datefmt = self.setup_logging_timestamp()
+        formatter = logging.Formatter(fmt, datefmt)
+        handler.setFormatter(formatter)
+
+        return handler
+
+    def setup_logging_format(self): # pragma: no cover
+        '''Return format string for log messages.'''
+        return '%(asctime)s %(levelname)s %(message)s'
+
+    def setup_logging_timestamp(self): # pragma: no cover
+        '''Return timestamp format string for log message.'''
+        return '%Y-%m-%d %H:%M:%S'
+
+    def log_config(self):
+        logging.info('%s version %s starts' %
+                     (self.settings.progname, self.settings.version))
+        logging.debug('sys.argv: %s' % sys.argv)
+        logging.debug('environment variables:')
+        for name in os.environ:
+            logging.debug('environment: %s=%s' % (name, os.environ[name]))
+        cp = self.settings.as_cp()
+        f = StringIO.StringIO()
+        cp.write(f)
+        logging.debug('Config:\n%s' % f.getvalue())
+        logging.debug('Python version: %s' % sys.version)
+
+    def app_directory(self):
+        '''Return the directory where the application class is defined.
+
+        Plugins are searched relative to this directory, in the subdirectory
+        specified by self.plugin_subdir.
+
+        '''
+
+        module_name = self.__class__.__module__
+        module = sys.modules[module_name]
+        dirname = os.path.dirname(module.__file__) or '.'
+        return dirname
+
+    def setup_plugin_manager(self):
+        '''Create a plugin manager.'''
+        self.pluginmgr = cliapp.PluginManager()
+        dirname = os.path.join(self.app_directory(), self.plugin_subdir)
+        self.pluginmgr.locations = [dirname]
+
+    def enable_plugins(self): # pragma: no cover
+        '''Load plugins.'''
+        for plugin in self.pluginmgr.plugins:
+            plugin.app = self
+            plugin.setup()
+        self.pluginmgr.enable_plugins()
+
+    def disable_plugins(self):
+        self.pluginmgr.disable_plugins()
+
+    def parse_args(self, args, configs_only=False):
+        '''Parse the command line.
+
+        Return list of non-option arguments.
+
+        '''
+
+        return self.settings.parse_args(
+            args, configs_only=configs_only, arg_synopsis=self.arg_synopsis,
+            cmd_synopsis=self.cmd_synopsis,
+            compute_setting_values=self.compute_setting_values)
+
+    def setup(self):
+        '''Prepare for process_args.
+
+        This method is called just before enabling plugins. By default it
+        does nothing, but subclasses may override it with a suitable
+        implementation. This is easier than overriding process_args
+        itself.
+
+        '''
+
+    def cleanup(self):
+        '''Clean up after process_args.
+
+        This method is called just after process_args. By default it
+        does nothing, but subclasses may override it with a suitable
+        implementation. This is easier than overriding process_args
+        itself.
+
+        '''
+
+    def process_args(self, args):
+        '''Process command line non-option arguments.
+
+        The default is to call process_inputs with the argument list,
+        or to invoke the requested subcommand, if subcommands have
+        been defined.
+
+        '''
+
+
+        if self.subcommands:
+            if not args:
+                raise SystemExit('must give subcommand')
+
+            cmd = args[0]
+            if cmd not in self.subcommands:
+                for name in self.subcommand_aliases:
+                    if cmd in self.subcommand_aliases[name]:
+                        cmd = name
+                        break
+                else:
+                    raise SystemExit('unknown subcommand %s' % args[0])
+
+            method = self.subcommands[cmd]
+            method(args[1:])
+        else:
+            self.process_inputs(args)
+
+    def process_inputs(self, args):
+        '''Process all arguments as input filenames.
+
+        The default implementation calls process_input for each
+        input filename. If no filenames were given, then
+        process_input is called with ``-`` as the argument name.
+        This implements the usual Unix command line practice of
+        reading from stdin if no inputs are named.
+
+        The attributes ``fileno``, ``global_lineno``, and ``lineno`` are set,
+        and count files and lines. The global line number is the
+        line number as if all input files were one.
+
+        '''
+
+        for arg in args or ['-']:
+            self.process_input(arg)
+
+    def open_input(self, name, mode='r'):
+        '''Open an input file for reading.
+
+        The default behaviour is to open a file named on the local
+        filesystem. A subclass might override this behavior for URLs,
+        for example.
+
+        The optional mode argument speficies the mode in which the file
+        gets opened. It should allow reading. Some files should perhaps
+        be opened in binary mode ('rb') instead of the default text mode.
+
+        '''
+
+        if name == '-':
+            return sys.stdin
+        else:
+            return open(name, mode)
+
+    def process_input(self, name, stdin=sys.stdin):
+        '''Process a particular input file.
+
+        The ``stdin`` argument is meant for unit test only.
+
+        '''
+
+        self.fileno += 1
+        self.lineno = 0
+        f = self.open_input(name)
+        for line in f:
+            self.global_lineno += 1
+            self.lineno += 1
+            self.process_input_line(name, line)
+        if f != stdin:
+            f.close()
+
+    def process_input_line(self, filename, line):
+        '''Process one line of the input file.
+
+        Applications that are line-oriented can redefine only this method in
+        a subclass, and should not need to care about the other methods.
+
+        '''
+
+    def runcmd(self, *args, **kwargs): # pragma: no cover
+        return cliapp.runcmd(*args, **kwargs)
+
+    def runcmd_unchecked(self, *args, **kwargs): # pragma: no cover
+        return cliapp.runcmd_unchecked(*args, **kwargs)
+
+    def _vmrss(self): # pragma: no cover
+        '''Return current resident memory use, in KiB.'''
+        f = open('/proc/self/status')
+        rss = 0
+        for line in f:
+            if line.startswith('VmRSS'):
+                rss = line.split()[1]
+        f.close()
+        return rss
+
+    def dump_memory_profile(self, msg): # pragma: no cover
+        '''Log memory profiling information.
+
+        Get the memory profiling method from the dump-memory-profile
+        setting, and log the results at DEBUG level. ``msg`` is a
+        message the caller provides to identify at what point the profiling
+        happens.
+
+        '''
+
+        kind = self.settings['dump-memory-profile']
+        interval = self.settings['memory-dump-interval']
+
+        if kind == 'none':
+            return
+
+        now = time.time()
+        if self.last_memory_dump + interval > now:
+            return
+        self.last_memory_dump = now
+
+        # Log wall clock and CPU times for self, children.
+        utime, stime, cutime, cstime, elapsed_time = os.times()
+        duration = elapsed_time - self._started
+        logging.debug('process duration: %s s' % duration)
+        logging.debug('CPU time, in process: %s s' % utime)
+        logging.debug('CPU time, in system: %s s' % stime)
+        logging.debug('CPU time, in children: %s s' % cutime)
+        logging.debug('CPU time, in system for children: %s s' % cstime)
+
+        logging.debug('dumping memory profiling data: %s' % msg)
+        logging.debug('VmRSS: %s KiB' % self._vmrss())
+
+        if kind == 'simple':
+            return
+
+        # These are fairly expensive operations, so we only log them
+        # if we're doing expensive stuff anyway.
+        logging.debug('# objects: %d' % len(gc.get_objects()))
+        logging.debug('# garbage: %d' % len(gc.garbage))
+
+        if kind == 'heapy':
+            from guppy import hpy
+            h = hpy()
+            logging.debug('memory profile:\n%s' % h.heap())
+        elif kind == 'meliae':
+            filename = 'obnam-%d.meliae' % self.memory_dump_counter
+            logging.debug('memory profile: see %s' % filename)
+            from meliae import scanner
+            scanner.dump_all_objects(filename)
+            self.memory_dump_counter += 1
+
diff --git a/cliapp/app_tests.py b/cliapp/app_tests.py
new file mode 100644
index 00000000..080a6007
--- /dev/null
+++ b/cliapp/app_tests.py
@@ -0,0 +1,331 @@
+# Copyright (C) 2011  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import optparse
+import os
+import StringIO
+import sys
+import tempfile
+import unittest
+
+import cliapp
+
+
+def devnull(msg):
+    pass
+
+
+class AppExceptionTests(unittest.TestCase):
+
+    def setUp(self):
+        self.e = cliapp.AppException('foo')
+
+    def test_error_message_contains_foo(self):
+        self.assert_('foo' in str(self.e))
+
+
+class ApplicationTests(unittest.TestCase):
+
+    def setUp(self):
+        self.app = cliapp.Application()
+
+    def test_creates_settings(self):
+        self.assert_(isinstance(self.app.settings, cliapp.Settings))
+
+    def test_calls_add_settings_only_in_run(self):
+
+        class Foo(cliapp.Application):
+            def process_args(self, args):
+                pass
+            def add_settings(self):
+                self.settings.string(['foo'], '')
+        foo = Foo()
+        self.assertFalse('foo' in foo.settings)
+        foo.run(args=[])
+        self.assert_('foo' in foo.settings)
+
+    def test_run_uses_string_list_options_only_once(self):
+
+        class Foo(cliapp.Application):
+            def add_settings(self):
+                self.settings.string_list(['foo'], '')
+            def process_args(self, args):
+                pass
+        foo = Foo()
+        foo.run(args=['--foo=yo'])
+        self.assertEqual(foo.settings['foo'], ['yo'])
+
+    def test_run_sets_up_logging(self):
+        self.called = False
+        def setup():
+            self.called = True
+        self.app.setup_logging = setup
+        self.app.process_args = lambda args: None
+        self.app.run([])
+        self.assert_(self.called)
+
+    def test_run_sets_progname_from_sysargv0(self):
+        self.app.process_args = lambda args: None
+        self.app.run(args=[], sysargv=['foo'])
+        self.assertEqual(self.app.settings.progname, 'foo')
+
+    def test_run_calls_process_args(self):
+        self.called = None
+        self.app.process_args = lambda args: setattr(self, 'called', args)
+        self.app.run(args=['foo', 'bar'])
+        self.assertEqual(self.called, ['foo', 'bar'])
+
+    def test_run_processes_input_files(self):
+        self.inputs = []
+        self.app.process_input = lambda name: self.inputs.append(name)
+        self.app.run(args=['foo', 'bar'])
+        self.assertEqual(self.inputs, ['foo', 'bar'])
+
+    def test_run_sets_output_attribute(self):
+        self.app.process_args = lambda args: None
+        self.app.run(args=[])
+        self.assertEqual(self.app.output, sys.stdout)
+
+    def test_run_sets_output_to_file_if_output_option_is_set(self):
+        self.app.process_args = lambda args: None
+        self.app.run(args=['--output=/dev/null'])
+        self.assertEqual(self.app.output.name, '/dev/null')
+
+    def test_run_calls_parse_args(self):
+        class DummyOptions(object):
+            def __init__(self):
+                self.output = None
+                self.log = None
+        self.called = None
+        self.app.parse_args = lambda args, **kw: setattr(self, 'called', args)
+        self.app.process_args = lambda args: None
+        self.app.settings.options = DummyOptions()
+        self.app.run(args=['foo', 'bar'])
+        self.assertEqual(self.called, ['foo', 'bar'])
+
+    def test_makes_envname_correctly(self):
+        self.assertEqual(self.app._envname('foo'), 'FOO')
+        self.assertEqual(self.app._envname('foo.py'), 'FOO')
+        self.assertEqual(self.app._envname('foo bar'), 'FOO_BAR')
+        self.assertEqual(self.app._envname('foo-bar'), 'FOO_BAR')
+        self.assertEqual(self.app._envname('foo/bar'), 'BAR')
+        self.assertEqual(self.app._envname('foo_bar'), 'FOO_BAR')
+
+    def test_parses_options(self):
+        self.app.settings.string(['foo'], 'foo help')
+        self.app.settings.boolean(['bar'], 'bar help')
+        self.app.parse_args(['--foo=foovalue', '--bar'])
+        self.assertEqual(self.app.settings['foo'], 'foovalue')
+        self.assertEqual(self.app.settings['bar'], True)
+
+    def test_calls_setup(self):
+        class App(cliapp.Application):
+            def setup(self):
+                self.setup_called = True
+            def process_inputs(self, args):
+                pass
+        app = App()
+        app.run(args=[])
+        self.assertTrue(app.setup_called)
+
+    def test_calls_cleanup(self):
+        class App(cliapp.Application):
+            def cleanup(self):
+                self.cleanup_called = True
+            def process_inputs(self, args):
+                pass
+        app = App()
+        app.run(args=[])
+        self.assertTrue(app.cleanup_called)
+
+    def test_process_args_calls_process_inputs(self):
+        self.called = False
+        def process_inputs(args):
+            self.called = True
+        self.app.process_inputs = process_inputs
+        self.app.process_args([])
+        self.assert_(self.called)
+
+    def test_process_inputs_calls_process_input_for_each_arg(self):
+        self.args = []
+        def process_input(arg):
+            self.args.append(arg)
+        self.app.process_input = process_input
+        self.app.process_inputs(['foo', 'bar'])
+        self.assertEqual(self.args, ['foo', 'bar'])
+
+    def test_process_inputs_calls_process_input_with_dash_if_no_inputs(self):
+        self.args = []
+        def process_input(arg):
+            self.args.append(arg)
+        self.app.process_input = process_input
+        self.app.process_inputs([])
+        self.assertEqual(self.args, ['-'])
+
+    def test_open_input_opens_file(self):
+        f = self.app.open_input('/dev/null')
+        self.assert_(isinstance(f, file))
+        self.assertEqual(f.mode, 'r')
+
+    def test_open_input_opens_file_in_binary_mode_when_requested(self):
+        f = self.app.open_input('/dev/null', mode='rb')
+        self.assertEqual(f.mode, 'rb')
+
+    def test_open_input_opens_stdin_if_dash_given(self):
+        self.assertEqual(self.app.open_input('-'), sys.stdin)
+
+    def test_process_input_calls_open_input(self):
+        self.called = None
+        def open_input(name):
+            self.called = name
+            return StringIO.StringIO('')
+        self.app.open_input = open_input
+        self.app.process_input('foo')
+        self.assertEqual(self.called, 'foo')
+
+    def test_process_input_does_not_close_stdin(self):
+        self.closed = False
+        def close():
+            self.closed = True
+        f = StringIO.StringIO('')
+        f.close = close
+        def open_input(name):
+            if name == '-':
+                return f
+        self.app.open_input = open_input
+        self.app.process_input('-', stdin=f)
+        self.assertEqual(self.closed, False)
+
+    def test_processes_input_lines(self):
+
+        lines = []
+        class Foo(cliapp.Application):
+            def open_input(self, name):
+                return StringIO.StringIO(''.join('%s%d\n' % (name, i)
+                                                 for i in range(2)))
+            def process_input_line(self, name, line):
+                lines.append(line)
+
+        foo = Foo()
+        foo.run(args=['foo', 'bar'])
+        self.assertEqual(lines, ['foo0\n', 'foo1\n', 'bar0\n', 'bar1\n'])
+
+    def test_process_input_line_can_access_counters(self):
+        counters = []
+        class Foo(cliapp.Application):
+            def open_input(self, name):
+                return StringIO.StringIO(''.join('%s%d\n' % (name, i)
+                                                 for i in range(2)))
+            def process_input_line(self, name, line):
+                counters.append((self.fileno, self.global_lineno, self.lineno))
+
+        foo = Foo()
+        foo.run(args=['foo', 'bar'])
+        self.assertEqual(counters,
+                         [(1, 1, 1),
+                          (1, 2, 2),
+                          (2, 3, 1),
+                          (2, 4, 2)])
+
+    def test_run_prints_out_error_for_appexception(self):
+        def raise_error(args):
+            raise cliapp.AppException('xxx')
+        self.app.process_args = raise_error
+        f = StringIO.StringIO()
+        self.assertRaises(SystemExit, self.app.run, [], stderr=f, log=devnull)
+        self.assert_('xxx' in f.getvalue())
+
+    def test_run_prints_out_stack_trace_for_not_appexception(self):
+        def raise_error(args):
+            raise Exception('xxx')
+        self.app.process_args = raise_error
+        f = StringIO.StringIO()
+        self.assertRaises(SystemExit, self.app.run, [], stderr=f, log=devnull)
+        self.assert_('Traceback' in f.getvalue())
+
+    def test_run_raises_systemexit_for_systemexit(self):
+        def raise_error(args):
+            raise SystemExit(123)
+        self.app.process_args = raise_error
+        f = StringIO.StringIO()
+        self.assertRaises(SystemExit, self.app.run, [], stderr=f, log=devnull)
+
+    def test_run_raises_systemexit_for_keyboardint(self):
+        def raise_error(args):
+            raise KeyboardInterrupt()
+        self.app.process_args = raise_error
+        f = StringIO.StringIO()
+        self.assertRaises(SystemExit, self.app.run, [], stderr=f, log=devnull)
+
+
+class DummySubcommandApp(cliapp.Application):
+
+    def cmd_foo(self, args):
+        self.foo_called = True
+
+
+class SubcommandTests(unittest.TestCase):
+
+    def setUp(self):
+        self.app = DummySubcommandApp()
+        self.trash = StringIO.StringIO()
+
+    def test_lists_subcommands(self):
+        self.assertEqual(self.app._subcommand_methodnames(), ['cmd_foo'])
+
+    def test_normalizes_subcommand(self):
+        self.assertEqual(self.app._normalize_cmd('foo'), 'cmd_foo')
+        self.assertEqual(self.app._normalize_cmd('foo-bar'), 'cmd_foo_bar')
+
+    def test_raises_error_for_no_subcommand(self):
+        self.assertRaises(SystemExit, self.app.run, [],
+                          stderr=self.trash, log=devnull)
+
+    def test_raises_error_for_unknown_subcommand(self):
+        self.assertRaises(SystemExit, self.app.run, ['what?'],
+                          stderr=self.trash, log=devnull)
+
+    def test_calls_subcommand_method(self):
+        self.app.run(['foo'], stderr=self.trash, log=devnull)
+        self.assert_(self.app.foo_called)
+
+    def test_calls_subcommand_method_via_alias(self):
+        self.bar_called = False
+        def bar(*args):
+            self.bar_called = True
+        self.app.add_subcommand('bar', bar, aliases=['yoyo'])
+        self.app.run(['yoyo'], stderr=self.trash, log=devnull)
+        self.assertTrue(self.bar_called)
+
+    def test_adds_default_subcommand_help(self):
+        self.app.run(['foo'], stderr=self.trash, log=devnull)
+        self.assertTrue('help' in self.app.subcommands)
+
+
+class ExtensibleSubcommandTests(unittest.TestCase):
+
+    def setUp(self):
+        self.app = cliapp.Application()
+
+    def test_lists_no_subcommands(self):
+        self.assertEqual(self.app.subcommands, {})
+
+    def test_adds_subcommand(self):
+        help = lambda args: None
+        self.app.add_subcommand('foo', help)
+        self.assertEqual(self.app.subcommands, {'foo': help})
+
diff --git a/cliapp/fmt.py b/cliapp/fmt.py
new file mode 100644
index 00000000..1358b0ab
--- /dev/null
+++ b/cliapp/fmt.py
@@ -0,0 +1,125 @@
+# Copyright (C) 2013  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+'''Simplistic text re-formatter.
+
+This module format text, paragraph by paragraph, so it is somewhat
+nice-looking, with no line too long, and short lines joined. In
+other words, like what the textwrap library does. However, it
+extends textwrap by recognising bulleted lists.
+
+'''
+
+
+import textwrap
+
+
+class Paragraph(object):
+
+    def __init__(self):
+        self._lines = []
+
+    def append(self, line):
+        self._lines.append(line)
+
+    def _oneliner(self):
+        return ' '.join(' '.join(x.split()) for x in self._lines)
+
+    def fill(self, width):
+        filled = textwrap.fill(self._oneliner(), width=width)
+        return filled
+
+
+class BulletPoint(Paragraph):
+
+    def fill(self, width):
+        text = self._oneliner()
+        assert text.startswith('* ')
+        filled = textwrap.fill(text[2:], width=width - 2)
+        lines = ['  %s' % x for x in filled.splitlines(True)]
+        lines[0] = '* %s' % lines[0][2:]
+        return ''.join(lines)
+
+
+class EmptyLine(Paragraph):
+
+    def fill(self, width):
+        return ''
+
+
+class TextFormat(object):
+
+    def __init__(self, width=78):
+        self._width = width
+
+    def format(self, text):
+        '''Return input string, but formatted nicely.'''
+
+        filled_paras = []
+        for para in self._paragraphs(text):
+            filled_paras.append(para.fill(self._width))
+        filled = '\n'.join(filled_paras)
+        if text and not filled.endswith('\n'):
+            filled += '\n'
+        return filled
+
+    def _paragraphs(self, text):
+
+        def is_empty(line):
+            return line.strip() == ''
+
+        def is_bullet(line):
+            return line.startswith('* ')
+
+        def is_continuation(line):
+            return line.startswith(' ')
+
+        current = None
+        in_list = False
+        for line in text.splitlines(True):
+            if in_list and is_continuation(line):
+                assert current is not None
+                current.append(line)
+            elif is_bullet(line):
+                if current:
+                    yield current
+                    if not in_list:
+                        yield EmptyLine()
+                current = BulletPoint()
+                current.append(line)
+                in_list = True
+            elif is_empty(line):
+                if current:
+                    yield current
+                    yield EmptyLine()
+                current = None
+                in_list = False
+            else:
+                if in_list:
+                    yield current
+                    yield EmptyLine()
+                    current = None
+
+                if not current:
+                    current = Paragraph()
+                current.append(line)
+                in_list = False
+
+        if current:
+            yield current
+
+
diff --git a/cliapp/fmt_tests.py b/cliapp/fmt_tests.py
new file mode 100644
index 00000000..79f1ab6b
--- /dev/null
+++ b/cliapp/fmt_tests.py
@@ -0,0 +1,59 @@
+# Copyright (C) 2013  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import unittest
+
+import cliapp
+
+
+class TextFormatTests(unittest.TestCase):
+
+    def setUp(self):
+        self.fmt = cliapp.TextFormat(width=10)
+
+    def test_returns_empty_string_for_empty_string(self):
+        self.assertEqual(self.fmt.format(''), '')
+
+    def test_returns_short_one_line_paragraph_as_is(self):
+        self.assertEqual(self.fmt.format('foo bar'), 'foo bar\n')
+
+    def test_collapse_multiple_spaces_into_one(self):
+        self.assertEqual(self.fmt.format('foo    bar'), 'foo bar\n')
+
+    def test_wraps_long_line(self):
+        self.assertEqual(self.fmt.format('foobar word'), 'foobar\nword\n')
+
+    def test_handles_paragraphs(self):
+        self.assertEqual(
+            self.fmt.format('foo\nbar\n\nyo\nyo\n'),
+            'foo bar\n\nyo yo\n')
+
+    def test_collapses_more_than_two_empty_lines(self):
+        self.assertEqual(
+            self.fmt.format('foo\nbar\n\n\n\n\n\n\n\n\n\nyo\nyo\n'),
+            'foo bar\n\nyo yo\n')
+
+    def test_handles_bulleted_lists(self):
+        self.assertEqual(
+            self.fmt.format('foo\nbar\n\n* yo\n* a\n  and b\n\nword'),
+            'foo bar\n\n* yo\n* a and b\n\nword\n')
+
+    def test_handles_bulleted_lists_without_surrounding_empty_lines(self):
+        self.assertEqual(
+            self.fmt.format('foo\nbar\n* yo\n* a\n  and b\nword'),
+            'foo bar\n\n* yo\n* a and b\n\nword\n')
+
diff --git a/cliapp/genman.py b/cliapp/genman.py
new file mode 100644
index 00000000..e81fcfee
--- /dev/null
+++ b/cliapp/genman.py
@@ -0,0 +1,148 @@
+# Copyright (C) 2011  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import optparse
+import re
+
+
+class ManpageGenerator(object):
+
+    '''Fill in a manual page template from an OptionParser instance.'''
+
+    def __init__(self, template, parser, arg_synopsis, cmd_synopsis):
+        self.template = template
+        self.parser = parser
+        self.arg_synopsis = arg_synopsis
+        self.cmd_synopsis = cmd_synopsis
+
+    def sort_options(self, options):
+        return sorted(options,
+                      key=lambda o: (o._long_opts + o._short_opts)[0])
+
+    def option_list(self, container):
+        return self.sort_options(container.option_list)
+
+    @property
+    def options(self):
+        return self.option_list(self.parser)
+
+    def format_template(self):
+        sections = (('SYNOPSIS', self.format_synopsis()),
+                    ('OPTIONS', self.format_options()))
+        text = self.template
+        for section, contents in sections:
+            pattern = '\n.SH %s\n' % section
+            text = text.replace(pattern, pattern + contents)
+        return text
+
+    def format_synopsis(self):
+        lines = []
+        lines += ['.nh']
+        lines += ['.B %s' % self.esc_dashes(self.parser.prog)]
+
+        all_options = self.option_list(self.parser)
+        for group in self.parser.option_groups:
+            all_options += self.option_list(group)
+        for option in self.sort_options(all_options):
+            for spec in self.format_option_for_synopsis(option):
+                lines += ['.RB [ %s ]' % spec]
+
+        if self.cmd_synopsis:
+            lines += ['.PP']
+            for cmd in sorted(self.cmd_synopsis):
+                lines += ['.br',
+                          '.B %s' % self.esc_dashes(self.parser.prog),
+                          '.RI [ options ]',
+                          self.esc_dashes(cmd)]
+                lines += self.format_argspec(self.cmd_synopsis[cmd])
+        elif self.arg_synopsis:
+            lines += self.format_argspec(self.arg_synopsis)
+
+        lines += ['.hy']
+        return ''.join('%s\n' % line for line in lines)
+
+    def format_option_for_synopsis(self, option):
+        if option.metavar:
+            suffix = '\\fR=\\fI%s' % self.esc_dashes(option.metavar)
+        else:
+            suffix = ''
+        for name in option._short_opts + option._long_opts:
+            yield '%s%s' % (self.esc_dashes(name), suffix)
+
+    def format_options(self):
+        lines = []
+
+        for option in self.sort_options(self.parser.option_list):
+            lines += self.format_option_for_options(option)
+
+        for group in self.parser.option_groups:
+            lines += ['.SS "%s"' % group.title]
+            for option in self.sort_options(group.option_list):
+                lines += self.format_option_for_options(option)
+
+        return ''.join('%s\n' % line for line in lines)
+
+    def format_option_for_options(self, option):
+        lines = []
+        lines += ['.TP']
+        shorts = [self.esc_dashes(x) for x in option._short_opts]
+        if option.metavar:
+            longs = ['%s =\\fI%s' % (self.esc_dashes(x), option.metavar)
+                     for x in option._long_opts]
+        else:
+            longs = ['%s' % self.esc_dashes(x)
+                     for x in option._long_opts]
+        lines += ['.BR ' + ' ", " '.join(shorts + longs)]
+        lines += [self.esc_dots(self.expand_default(option).strip())]
+        return lines
+
+    def expand_default(self, option):
+        default = self.parser.defaults.get(option.dest)
+        if default is optparse.NO_DEFAULT or default is None:
+            default = 'none'
+        else:
+            default = str(default)
+        return option.help.replace('%default', default)
+
+    def esc_dashes(self, optname):
+        return '\\-'.join(optname.split('-'))
+
+    def esc_dots(self, line):
+        if line.startswith('.'):
+            return '\\' + line
+        else:
+            return line
+
+    def format_argspec(self, argspec):
+        roman = re.compile(r'[^A-Z]+')
+        italic = re.compile(r'[A-Z]+')
+        words = ['.RI']
+        while argspec:
+            m = roman.match(argspec)
+            if m:
+                words += [self.esc_dashes(m.group(0))]
+                argspec = argspec[m.end():]
+            else:
+                words += ['""']
+            m = italic.match(argspec)
+            if m:
+                words += [self.esc_dashes(m.group(0))]
+                argspec = argspec[m.end():]
+            else:
+                words += ['""']
+        return [' '.join(words)]
+
diff --git a/cliapp/hook.py b/cliapp/hook.py
new file mode 100644
index 00000000..d453f2e6
--- /dev/null
+++ b/cliapp/hook.py
@@ -0,0 +1,76 @@
+# Copyright (C) 2009-2012  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+'''Hooks with callbacks.
+
+In order to de-couple parts of the application, especially when plugins
+are used, hooks can be used. A hook is a location in the application
+code where plugins may want to do something. Each hook has a name and
+a list of callbacks. The application defines the name and the location
+where the hook will be invoked, and the plugins (or other parts of the
+application) will register callbacks.
+
+'''
+
+
+class Hook(object):
+
+    '''A hook.'''
+
+    def __init__(self):
+        self.callbacks = []
+
+    def add_callback(self, callback):
+        '''Add a callback to this hook.
+
+        Return an identifier that can be used to remove this callback.
+
+        '''
+
+        if callback not in self.callbacks:
+            self.callbacks.append(callback)
+        return callback
+
+    def call_callbacks(self, *args, **kwargs):
+        '''Call all callbacks with the given arguments.'''
+        for callback in self.callbacks:
+            callback(*args, **kwargs)
+
+    def remove_callback(self, callback_id):
+        '''Remove a specific callback.'''
+        if callback_id in self.callbacks:
+            self.callbacks.remove(callback_id)
+
+
+class FilterHook(Hook):
+
+    '''A hook which filters data through callbacks.
+
+    Every hook of this type accepts a piece of data as its first argument
+    Each callback gets the return value of the previous one as its
+    argument. The caller gets the value of the final callback.
+
+    Other arguments (with or without keywords) are passed as-is to
+    each callback.
+
+    '''
+
+    def call_callbacks(self, data, *args, **kwargs):
+        for callback in self.callbacks:
+            data = callback(data, *args, **kwargs)
+        return data
+
diff --git a/cliapp/hook_tests.py b/cliapp/hook_tests.py
new file mode 100644
index 00000000..a32f33af
--- /dev/null
+++ b/cliapp/hook_tests.py
@@ -0,0 +1,79 @@
+# Copyright (C) 2009-2012  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import unittest
+
+from cliapp import Hook, FilterHook
+
+
+class HookTests(unittest.TestCase):
+
+    def setUp(self):
+        self.hook = Hook()
+
+    def callback(self, *args, **kwargs):
+        self.args = args
+        self.kwargs = kwargs
+
+    def test_has_no_callbacks_by_default(self):
+        self.assertEqual(self.hook.callbacks, [])
+
+    def test_adds_callback(self):
+        self.hook.add_callback(self.callback)
+        self.assertEqual(self.hook.callbacks, [self.callback])
+
+    def test_adds_callback_only_once(self):
+        self.hook.add_callback(self.callback)
+        self.hook.add_callback(self.callback)
+        self.assertEqual(self.hook.callbacks, [self.callback])
+
+    def test_calls_callback(self):
+        self.hook.add_callback(self.callback)
+        self.hook.call_callbacks('bar', kwarg='foobar')
+        self.assertEqual(self.args, ('bar',))
+        self.assertEqual(self.kwargs, { 'kwarg': 'foobar' })
+
+    def test_removes_callback(self):
+        cb_id = self.hook.add_callback(self.callback)
+        self.hook.remove_callback(cb_id)
+        self.assertEqual(self.hook.callbacks, [])
+
+
+class FilterHookTests(unittest.TestCase):
+
+    def setUp(self):
+        self.hook = FilterHook()
+
+    def callback(self, data, *args, **kwargs):
+        self.args = args
+        self.kwargs = kwargs
+        return data + ['callback']
+
+    def test_returns_argument_if_no_callbacks(self):
+        self.assertEqual(self.hook.call_callbacks(['foo']), ['foo'])
+
+    def test_calls_callback_and_returns_modified_data(self):
+        self.hook.add_callback(self.callback)
+        data = self.hook.call_callbacks([])
+        self.assertEqual(data, ['callback'])
+
+    def test_calls_callback_with_extra_args(self):
+        self.hook.add_callback(self.callback)
+        self.hook.call_callbacks(['data'], 'extra', kwextra='kwextra')
+        self.assertEqual(self.args, ('extra',))
+        self.assertEqual(self.kwargs, { 'kwextra': 'kwextra' })
+
diff --git a/cliapp/hookmgr.py b/cliapp/hookmgr.py
new file mode 100644
index 00000000..80db2d0a
--- /dev/null
+++ b/cliapp/hookmgr.py
@@ -0,0 +1,46 @@
+# Copyright (C) 2009-2012  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+class HookManager(object):
+
+    '''Manage the set of hooks the application defines.'''
+
+    def __init__(self):
+        self.hooks = {}
+
+    def new(self, name, hook):
+        '''Add a new hook to the manager.
+
+        If a hook with that name already exists, nothing happens.
+
+        '''
+
+        if name not in self.hooks:
+            self.hooks[name] = hook
+
+    def add_callback(self, name, callback):
+        '''Add a callback to a named hook.'''
+        return self.hooks[name].add_callback(callback)
+
+    def remove_callback(self, name, callback_id):
+        '''Remove a specific callback from a named hook.'''
+        self.hooks[name].remove_callback(callback_id)
+
+    def call(self, name, *args, **kwargs):
+        '''Call callbacks for a named hook, using given arguments.'''
+        return self.hooks[name].call_callbacks(*args, **kwargs)
+
diff --git a/cliapp/hookmgr_tests.py b/cliapp/hookmgr_tests.py
new file mode 100644
index 00000000..7abdeba4
--- /dev/null
+++ b/cliapp/hookmgr_tests.py
@@ -0,0 +1,59 @@
+# Copyright (C) 2009-2012  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import unittest
+
+from cliapp import HookManager, FilterHook
+
+
+class HookManagerTests(unittest.TestCase):
+
+    def setUp(self):
+        self.hooks = HookManager()
+        self.hooks.new('foo', FilterHook())
+
+    def callback(self, *args, **kwargs):
+        self.args = args
+        self.kwargs = kwargs
+
+    def test_has_no_tests_initially(self):
+        hooks = HookManager()
+        self.assertEqual(hooks.hooks, {})
+
+    def test_adds_new_hook(self):
+        self.assert_(self.hooks.hooks.has_key('foo'))
+
+    def test_adds_callback(self):
+        self.hooks.add_callback('foo', self.callback)
+        self.assertEqual(self.hooks.hooks['foo'].callbacks, [self.callback])
+
+    def test_removes_callback(self):
+        cb_id = self.hooks.add_callback('foo', self.callback)
+        self.hooks.remove_callback('foo', cb_id)
+        self.assertEqual(self.hooks.hooks['foo'].callbacks, [])
+
+    def test_calls_callbacks(self):
+        self.hooks.add_callback('foo', self.callback)
+        self.hooks.call('foo', 'bar', kwarg='foobar')
+        self.assertEqual(self.args, ('bar',))
+        self.assertEqual(self.kwargs, { 'kwarg': 'foobar' })
+
+    def test_call_returns_value_of_callbacks(self):
+        self.hooks.new('bar', FilterHook())
+        self.hooks.add_callback('bar', lambda data: data + 1)
+        self.assertEqual(self.hooks.call('bar', 1), 2)
+
diff --git a/cliapp/plugin.py b/cliapp/plugin.py
new file mode 100644
index 00000000..c6ea66fe
--- /dev/null
+++ b/cliapp/plugin.py
@@ -0,0 +1,125 @@
+# Copyright (C) 2009-2012  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+'''A generic plugin manager.
+
+The plugin manager finds files with plugins and loads them. It looks
+for plugins in a number of locations specified by the caller. To add
+a plugin to be loaded, it is enough to put it in one of the locations,
+and name it *_plugin.py. (The naming convention is to allow having
+other modules as well, such as unit tests, in the same locations.)
+
+'''
+
+
+import imp
+import inspect
+import os
+
+
+class Plugin(object):
+
+    '''Base class for plugins.
+
+    A plugin MUST NOT have any side effects when it is instantiated.
+    This is necessary so that it can be safely loaded by unit tests,
+    and so that a user interface can allow the user to disable it,
+    even if it is installed, with no ill effects. Any side effects
+    that would normally happen should occur in the enable() method,
+    and be undone by the disable() method. These methods must be
+    callable any number of times.
+
+    The subclass MAY define the following attributes:
+
+    * name
+    * description
+    * version
+    * required_application_version
+
+    name is the user-visible identifier for the plugin. It defaults
+    to the plugin's classname.
+
+    description is the user-visible description of the plugin. It may
+    be arbitrarily long, and can use pango markup language. Defaults
+    to the empty string.
+
+    version is the plugin version. Defaults to '0.0.0'. It MUST be a
+    sequence of integers separated by periods. If several plugins with
+    the same name are found, the newest version is used. Versions are
+    compared integer by integer, starting with the first one, and a
+    missing integer treated as a zero. If two plugins have the same
+    version, either might be used.
+
+    required_application_version gives the version of the minimal
+    application version the plugin is written for. The first integer
+    must match exactly: if the application is version 2.3.4, the
+    plugin's required_application_version must be at least 2 and
+    at most 2.3.4 to be loaded. Defaults to 0.
+
+    '''
+
+    @property
+    def name(self):
+        return self.__class__.__name__
+
+    @property
+    def description(self):
+        return ''
+
+    @property
+    def version(self):
+        return '0.0.0'
+
+    @property
+    def required_application_version(self):
+        return '0.0.0'
+
+    def setup(self):
+        '''Setup plugin.
+
+        This is called at plugin load time. It should not yet enable the
+        plugin (the ``enable`` method does that), but it might do things
+        like add itself into a hook that adds command line arguments
+        to the application.
+
+        '''
+
+    def enable_wrapper(self):
+        '''Enable plugin.
+
+        The plugin manager will call this method, which then calls the
+        enable method. Plugins should implement the enable method.
+        The wrapper method is there to allow an application to provide
+        an extended base class that does some application specific
+        magic when plugins are enabled or disabled.
+
+        '''
+
+        self.enable()
+
+    def disable_wrapper(self):
+        '''Corresponds to enable_wrapper, but for disabling a plugin.'''
+        self.disable()
+
+    def enable(self):
+        '''Enable the plugin.'''
+        raise NotImplemented()
+
+    def disable(self):
+        '''Disable the plugin.'''
+        raise NotImplemented()
+
diff --git a/cliapp/plugin_tests.py b/cliapp/plugin_tests.py
new file mode 100644
index 00000000..8c980397
--- /dev/null
+++ b/cliapp/plugin_tests.py
@@ -0,0 +1,55 @@
+# Copyright (C) 2009-2012  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import unittest
+
+from cliapp import Plugin
+
+
+class PluginTests(unittest.TestCase):
+
+    def setUp(self):
+        self.plugin = Plugin()
+
+    def test_name_is_class_name(self):
+        self.assertEqual(self.plugin.name, 'Plugin')
+
+    def test_description_is_empty_string(self):
+        self.assertEqual(self.plugin.description, '')
+
+    def test_version_is_zeroes(self):
+        self.assertEqual(self.plugin.version, '0.0.0')
+
+    def test_required_application_version_is_zeroes(self):
+        self.assertEqual(self.plugin.required_application_version, '0.0.0')
+
+    def test_enable_raises_exception(self):
+        self.assertRaises(Exception, self.plugin.enable)
+
+    def test_disable_raises_exception(self):
+        self.assertRaises(Exception, self.plugin.disable)
+
+    def test_enable_wrapper_calls_enable(self):
+        self.plugin.enable = lambda: setattr(self, 'enabled', True)
+        self.plugin.enable_wrapper()
+        self.assert_(self.enabled, True)
+
+    def test_disable_wrapper_calls_disable(self):
+        self.plugin.disable = lambda: setattr(self, 'disabled', True)
+        self.plugin.disable_wrapper()
+        self.assert_(self.disabled, True)
+
diff --git a/cliapp/pluginmgr.py b/cliapp/pluginmgr.py
new file mode 100644
index 00000000..5e995236
--- /dev/null
+++ b/cliapp/pluginmgr.py
@@ -0,0 +1,175 @@
+# Copyright (C) 2009-2012  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+'''A generic plugin manager.
+
+The plugin manager finds files with plugins and loads them. It looks
+for plugins in a number of locations specified by the caller. To add
+a plugin to be loaded, it is enough to put it in one of the locations,
+and name it *_plugin.py. (The naming convention is to allow having
+other modules as well, such as unit tests, in the same locations.)
+
+'''
+
+
+import imp
+import inspect
+import os
+
+
+from cliapp import Plugin
+
+
+class PluginManager(object):
+
+    '''Manage plugins.
+
+    This class finds and loads plugins, and keeps a list of them that
+    can be accessed in various ways.
+
+    The locations are set via the locations attribute, which is a list.
+
+    When a plugin is loaded, an instance of its class is created. This
+    instance is initialized using normal and keyword arguments specified
+    in the plugin manager attributes plugin_arguments and
+    plugin_keyword_arguments.
+
+    The version of the application using the plugin manager is set via
+    the application_version attribute. This defaults to '0.0.0'.
+
+    '''
+
+    suffix = '_plugin.py'
+
+    def __init__(self):
+        self.locations = []
+        self._plugins = None
+        self._plugin_files = None
+        self.plugin_arguments = []
+        self.plugin_keyword_arguments = {}
+        self.application_version = '0.0.0'
+
+    @property
+    def plugin_files(self):
+        if self._plugin_files is None:
+            self._plugin_files = self.find_plugin_files()
+        return self._plugin_files
+
+    @property
+    def plugins(self):
+        if self._plugins is None:
+            self._plugins = self.load_plugins()
+        return self._plugins
+
+    def __getitem__(self, name):
+        for plugin in self.plugins:
+            if plugin.name == name:
+                return plugin
+        raise KeyError('Plugin %s is not known' % name)
+
+    def find_plugin_files(self):
+        '''Find files that may contain plugins.
+
+        This finds all files named *_plugin.py in all locations.
+        The returned list is sorted.
+
+        '''
+
+        pathnames = []
+
+        for location in self.locations:
+            try:
+                basenames = os.listdir(location)
+            except os.error:
+                continue
+            for basename in basenames:
+                s = os.path.join(location, basename)
+                if s.endswith(self.suffix) and os.path.exists(s):
+                    pathnames.append(s)
+
+        return sorted(pathnames)
+
+    def load_plugins(self):
+        '''Load plugins from all plugin files.'''
+
+        plugins = dict()
+
+        for pathname in self.plugin_files:
+            for plugin in self.load_plugin_file(pathname):
+                if plugin.name in plugins:
+                    p = plugins[plugin.name]
+                    if self.is_older(p.version, plugin.version):
+                        plugins[plugin.name] = plugin
+                else:
+                    plugins[plugin.name] = plugin
+
+        return plugins.values()
+
+    def is_older(self, version1, version2):
+        '''Is version1 older than version2?'''
+        return self.parse_version(version1) < self.parse_version(version2)
+
+    def load_plugin_file(self, pathname):
+        '''Return plugin classes in a plugin file.'''
+
+        name, ext = os.path.splitext(os.path.basename(pathname))
+        f = file(pathname, 'r')
+        module = imp.load_module(name, f, pathname,
+                                 ('.py', 'r', imp.PY_SOURCE))
+        f.close()
+
+        plugins = []
+        for dummy, member in inspect.getmembers(module, inspect.isclass):
+            if issubclass(member, Plugin):
+                p = member(*self.plugin_arguments,
+                           **self.plugin_keyword_arguments)
+                if self.compatible_version(p.required_application_version):
+                    plugins.append(p)
+
+        return plugins
+
+    def compatible_version(self, required_application_version):
+        '''Check that the plugin is version-compatible with the application.
+
+        This checks the plugin's required_application_version against
+        the declared application version and returns True if they are
+        compatible, and False if not.
+
+        '''
+
+        req = self.parse_version(required_application_version)
+        app = self.parse_version(self.application_version)
+
+        return app[0] == req[0] and app >= req
+
+    def parse_version(self, version):
+        '''Parse a string represenation of a version into list of ints.'''
+
+        return [int(s) for s in version.split('.')]
+
+    def enable_plugins(self, plugins=None):
+        '''Enable all or selected plugins.'''
+
+        for plugin in plugins or self.plugins:
+            plugin.enable_wrapper()
+
+    def disable_plugins(self, plugins=None):
+        '''Disable all or selected plugins.'''
+
+        for plugin in plugins or self.plugins:
+            plugin.disable_wrapper()
+
diff --git a/cliapp/pluginmgr_tests.py b/cliapp/pluginmgr_tests.py
new file mode 100644
index 00000000..d458ac36
--- /dev/null
+++ b/cliapp/pluginmgr_tests.py
@@ -0,0 +1,118 @@
+# Copyright (C) 2009-2012  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import unittest
+
+from cliapp import PluginManager
+
+
+class PluginManagerInitialStateTests(unittest.TestCase):
+
+    def setUp(self):
+        self.pm = PluginManager()
+
+    def test_locations_is_empty_list(self):
+        self.assertEqual(self.pm.locations, [])
+
+    def test_plugins_is_empty_list(self):
+        self.assertEqual(self.pm.plugins, [])
+
+    def test_application_version_is_zeroes(self):
+        self.assertEqual(self.pm.application_version, '0.0.0')
+
+    def test_plugin_files_is_empty(self):
+        self.assertEqual(self.pm.plugin_files, [])
+
+    def test_plugin_arguments_is_empty(self):
+        self.assertEqual(self.pm.plugin_arguments, [])
+
+    def test_plugin_keyword_arguments_is_empty(self):
+        self.assertEqual(self.pm.plugin_keyword_arguments, {})
+
+
+class PluginManagerTests(unittest.TestCase):
+
+    def setUp(self):
+        self.pm = PluginManager()
+        self.pm.locations = ['test-plugins', 'not-exist']
+        self.pm.plugin_arguments = ('fooarg',)
+        self.pm.plugin_keyword_arguments = { 'bar': 'bararg' }
+
+        self.files = sorted(['test-plugins/hello_plugin.py',
+                             'test-plugins/aaa_hello_plugin.py',
+                             'test-plugins/oldhello_plugin.py',
+                             'test-plugins/wrongversion_plugin.py'])
+
+    def test_finds_the_right_plugin_files(self):
+        self.assertEqual(self.pm.find_plugin_files(), self.files)
+
+    def test_plugin_files_attribute_implicitly_searches(self):
+        self.assertEqual(self.pm.plugin_files, self.files)
+
+    def test_loads_hello_plugin(self):
+        plugins = self.pm.load_plugins()
+        self.assertEqual(len(plugins), 1)
+        self.assertEqual(plugins[0].name, 'Hello')
+
+    def test_plugins_attribute_implicitly_searches(self):
+        self.assertEqual(len(self.pm.plugins), 1)
+        self.assertEqual(self.pm.plugins[0].name, 'Hello')
+
+    def test_initializes_hello_with_correct_args(self):
+        plugin = self.pm['Hello']
+        self.assertEqual(plugin.foo, 'fooarg')
+        self.assertEqual(plugin.bar, 'bararg')
+
+    def test_raises_keyerror_for_unknown_plugin(self):
+        self.assertRaises(KeyError, self.pm.__getitem__, 'Hithere')
+
+    def test_enable_plugins_enables_all_plugins(self):
+        enabled = set()
+        for plugin in self.pm.plugins:
+            plugin.enable = lambda: enabled.add(plugin)
+        self.pm.enable_plugins()
+        self.assertEqual(enabled, set(self.pm.plugins))
+
+    def test_disable_plugins_disables_all_plugins(self):
+        disabled = set()
+        for plugin in self.pm.plugins:
+            plugin.disable = lambda: disabled.add(plugin)
+        self.pm.disable_plugins()
+        self.assertEqual(disabled, set(self.pm.plugins))
+
+
+class PluginManagerCompatibleApplicationVersionTests(unittest.TestCase):
+
+    def setUp(self):
+        self.pm = PluginManager()
+        self.pm.application_version = '1.2.3'
+
+    def test_rejects_zero(self):
+        self.assertFalse(self.pm.compatible_version('0'))
+
+    def test_rejects_two(self):
+        self.assertFalse(self.pm.compatible_version('2'))
+
+    def test_rejects_one_two_four(self):
+        self.assertFalse(self.pm.compatible_version('1.2.4'))
+
+    def test_accepts_one(self):
+        self.assert_(self.pm.compatible_version('1'))
+
+    def test_accepts_one_two_three(self):
+        self.assert_(self.pm.compatible_version('1.2.3'))
+
diff --git a/cliapp/runcmd.py b/cliapp/runcmd.py
new file mode 100644
index 00000000..6304a488
--- /dev/null
+++ b/cliapp/runcmd.py
@@ -0,0 +1,284 @@
+# Copyright (C) 2011, 2012  Lars Wirzenius
+# Copyright (C) 2012  Codethink Limited
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import errno
+import fcntl
+import logging
+import os
+import select
+import subprocess
+
+import cliapp
+
+
+def runcmd(argv, *args, **kwargs):
+    '''Run external command or pipeline.
+
+    Example: ``runcmd(['grep', 'foo'], ['wc', '-l'],
+                      feed_stdin='foo\nbar\n')``
+
+    Return the standard output of the command.
+
+    Raise ``cliapp.AppException`` if external command returns
+    non-zero exit code. ``*args`` and ``**kwargs`` are passed
+    onto ``subprocess.Popen``.
+
+    '''
+
+    our_options = (
+        ('ignore_fail', False),
+        ('log_error', True),
+    )
+    opts = {}
+    for name, default in our_options:
+        opts[name] = default
+        if name in kwargs:
+            opts[name] = kwargs[name]
+            del kwargs[name]
+
+    exit, out, err = runcmd_unchecked(argv, *args, **kwargs)
+    if exit != 0:
+        msg = 'Command failed: %s\n%s' % (' '.join(argv), err)
+        if opts['ignore_fail']:
+            if opts['log_error']:
+                logging.info(msg)
+        else:
+            if opts['log_error']:
+                logging.error(msg)
+            raise cliapp.AppException(msg)
+    return out
+
+def runcmd_unchecked(argv, *argvs, **kwargs):
+    '''Run external command or pipeline.
+
+    Return the exit code, and contents of standard output and error
+    of the command.
+
+    See also ``runcmd``.
+
+    '''
+
+    argvs = [argv] + list(argvs)
+    logging.debug('run external command: %s' % repr(argvs))
+
+    def pop_kwarg(name, default):
+        if name in kwargs:
+            value = kwargs[name]
+            del kwargs[name]
+            return value
+        else:
+            return default
+
+    feed_stdin = pop_kwarg('feed_stdin', '')
+    pipe_stdin = pop_kwarg('stdin', subprocess.PIPE)
+    pipe_stdout = pop_kwarg('stdout', subprocess.PIPE)
+    pipe_stderr = pop_kwarg('stderr', subprocess.PIPE)
+
+    try:
+        pipeline = _build_pipeline(argvs,
+                                   pipe_stdin,
+                                   pipe_stdout,
+                                   pipe_stderr,
+                                   kwargs)
+        return _run_pipeline(pipeline, feed_stdin, pipe_stdin,
+                              pipe_stdout, pipe_stderr)
+    except OSError, e: # pragma: no cover
+        if e.errno == errno.ENOENT and e.filename is None:
+            e.filename = argv[0]
+            raise e
+        else:
+            raise
+
+def _build_pipeline(argvs, pipe_stdin, pipe_stdout, pipe_stderr, kwargs):
+    procs = []
+    for i, argv in enumerate(argvs):
+        if i == 0 and i == len(argvs) - 1:
+            stdin = pipe_stdin
+            stdout = pipe_stdout
+            stderr = pipe_stderr
+        elif i == 0:
+            stdin = pipe_stdin
+            stdout = subprocess.PIPE
+            stderr = pipe_stderr
+        elif i == len(argvs) - 1:
+            stdin = procs[-1].stdout
+            stdout = pipe_stdout
+            stderr = pipe_stderr
+        else:
+            stdin = procs[-1].stdout
+            stdout = subprocess.PIPE
+            stderr = pipe_stderr
+        p = subprocess.Popen(argv, stdin=stdin, stdout=stdout,
+                             stderr=stderr, close_fds=True, **kwargs)
+        procs.append(p)
+
+    return procs
+
+def _run_pipeline(procs, feed_stdin, pipe_stdin, pipe_stdout, pipe_stderr):
+
+    stdout_eof = False
+    stderr_eof = False
+    out = []
+    err = []
+    pos = 0
+    io_size = 1024
+
+    def set_nonblocking(fd):
+        flags = fcntl.fcntl(fd, fcntl.F_GETFL, 0)
+        flags = flags | os.O_NONBLOCK
+        fcntl.fcntl(fd, fcntl.F_SETFL, flags)
+
+    if feed_stdin and pipe_stdin == subprocess.PIPE:
+        set_nonblocking(procs[0].stdin.fileno())
+    if pipe_stdout == subprocess.PIPE:
+        set_nonblocking(procs[-1].stdout.fileno())
+    if pipe_stderr == subprocess.PIPE:
+        set_nonblocking(procs[-1].stderr.fileno())
+
+    def still_running():
+        for p in procs:
+            p.poll()
+        for p in procs:
+            if p.returncode is None:
+                return True
+        if pipe_stdout == subprocess.PIPE and not stdout_eof:
+            return True
+        if pipe_stderr == subprocess.PIPE and not stderr_eof:
+            return True # pragma: no cover
+        return False
+
+    while still_running():
+        rlist = []
+        if not stdout_eof and pipe_stdout == subprocess.PIPE:
+            rlist.append(procs[-1].stdout)
+        if not stderr_eof and pipe_stderr == subprocess.PIPE:
+            rlist.append(procs[-1].stderr)
+
+        wlist = []
+        if pipe_stdin == subprocess.PIPE and pos < len(feed_stdin):
+            wlist.append(procs[0].stdin)
+
+        if rlist or wlist:
+            try:
+                r, w, x = select.select(rlist, wlist, [])
+            except select.error, e: # pragma: no cover
+                err, msg = e.args
+                if err == errno.EINTR:
+                    break
+                raise
+        else:
+            break # Let's not busywait waiting for processes to die.
+
+        if procs[0].stdin in w and pos < len(feed_stdin):
+            data = feed_stdin[pos : pos+io_size]
+            procs[0].stdin.write(data)
+            pos += len(data)
+            if pos >= len(feed_stdin):
+                procs[0].stdin.close()
+
+        if procs[-1].stdout in r:
+            data = procs[-1].stdout.read(io_size)
+            if data:
+                out.append(data)
+            else:
+                stdout_eof = True
+
+        if procs[-1].stderr in r:
+            data = procs[-1].stderr.read(io_size)
+            if data:
+                err.append(data)
+            else:
+                stderr_eof = True
+
+    while still_running():
+        for p in procs:
+            if p.returncode is None:
+                p.wait()
+
+    errorcodes = [p.returncode for p in procs if p.returncode != 0] or [0]
+    return errorcodes[-1], ''.join(out), ''.join(err)
+
+
+
+def shell_quote(s):
+    '''Return a shell-quoted version of s.'''
+
+    lower_ascii = 'abcdefghijklmnopqrstuvwxyz'
+    upper_ascii = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
+    digits = '0123456789'
+    punctuation = '-_/=.,:'
+    safe = set(lower_ascii + upper_ascii + digits + punctuation)
+
+    quoted = []
+    for c in s:
+        if c in safe:
+            quoted.append(c)
+        elif c == "'":
+            quoted.append('"\'"')
+        else:
+            quoted.append("'%c'" % c)
+
+    return ''.join(quoted)
+
+
+def ssh_runcmd(target, argv, **kwargs): # pragma: no cover
+    '''Run command in argv on remote host target.
+
+    This is similar to runcmd, but the command is run on the remote
+    machine. The command is given as an argv array; elements in the
+    array are automatically quoted so they get passed to the other
+    side correctly.
+
+    An optional ``tty=`` parameter can be passed to ``ssh_runcmd`` in
+    order to force or disable pseudo-tty allocation. This is often
+    required to run ``sudo`` on another machine and might be useful
+    in other situations as well. Supported values are ``tty=True`` for
+    forcing tty allocation, ``tty=False`` for disabling it and
+    ``tty=None`` for not passing anything tty related to ssh.
+
+    With the ``tty`` option,
+    ``cliapp.runcmd(['ssh', '-tt', 'user@host', '--', 'sudo', 'ls'])``
+    can be written as
+    ``cliapp.ssh_runcmd('user@host', ['sudo', 'ls'], tty=True)``
+    which is more intuitive.
+
+    The target is given as-is to ssh, and may use any syntax ssh
+    accepts.
+
+    Environment variables may or may not be passed to the remote
+    machine: this is dependent on the ssh and sshd configurations.
+    Invoke env(1) explicitly to pass in the variables you need to
+    exist on the other end.
+
+    Pipelines are not supported.
+
+    '''
+
+    tty = kwargs.get('tty', None)
+    if tty:
+        ssh_cmd = ['ssh', '-tt', target, '--']
+    elif tty is False:
+        ssh_cmd = ['ssh', '-T', target, '--']
+    else:
+        ssh_cmd = ['ssh', target, '--']
+    if 'tty' in kwargs:
+        del kwargs['tty']
+
+    local_argv = ssh_cmd + map(shell_quote, argv)
+    return runcmd(local_argv, **kwargs)
+
diff --git a/cliapp/runcmd_tests.py b/cliapp/runcmd_tests.py
new file mode 100644
index 00000000..e89b73ef
--- /dev/null
+++ b/cliapp/runcmd_tests.py
@@ -0,0 +1,144 @@
+# Copyright (C) 2011, 2012  Lars Wirzenius
+# Copyright (C) 2012  Codethink Limited
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import optparse
+import os
+import StringIO
+import subprocess
+import sys
+import tempfile
+import unittest
+
+import cliapp
+
+
+def devnull(msg):
+    pass
+
+
+class RuncmdTests(unittest.TestCase):
+
+    def test_runcmd_executes_true(self):
+        self.assertEqual(cliapp.runcmd(['true']), '')
+
+    def test_runcmd_raises_error_on_failure(self):
+        self.assertRaises(cliapp.AppException, cliapp.runcmd, ['false'])
+
+    def test_runcmd_returns_stdout_of_command(self):
+        self.assertEqual(cliapp.runcmd(['echo', 'hello', 'world']),
+                         'hello world\n')
+
+    def test_runcmd_returns_stderr_of_command(self):
+        exit, out, err = cliapp.runcmd_unchecked(['ls', 'notexist'])
+        self.assertNotEqual(exit, 0)
+        self.assertEqual(out, '')
+        self.assertNotEqual(err, '')
+
+    def test_runcmd_pipes_stdin_through_command(self):
+        self.assertEqual(cliapp.runcmd(['cat'], feed_stdin='hello, world'),
+                         'hello, world')
+
+    def test_runcmd_pipes_stdin_through_two_commands(self):
+        self.assertEqual(cliapp.runcmd(
+                            ['cat'], ['cat'], feed_stdin='hello, world'),
+                         'hello, world')
+
+    def test_runcmd_pipes_stdin_through_command_with_lots_of_data(self):
+        data = 'x' * (1024**2)
+        self.assertEqual(cliapp.runcmd(['cat'], feed_stdin=data), data)
+
+    def test_runcmd_ignores_failures_on_request(self):
+        self.assertEqual(cliapp.runcmd(['false'], ignore_fail=True), '')
+
+    def test_runcmd_obeys_cwd(self):
+        self.assertEqual(cliapp.runcmd(['pwd'], cwd='/'), '/\n')
+
+    def test_runcmd_unchecked_returns_values_on_success(self):
+        self.assertEqual(cliapp.runcmd_unchecked(['echo', 'foo']),
+                         (0, 'foo\n', ''))
+
+    def test_runcmd_unchecked_returns_values_on_failure(self):
+        self.assertEqual(cliapp.runcmd_unchecked(['false']),
+                         (1, '', ''))
+
+    def test_runcmd_unchecked_runs_simple_pipeline(self):
+        self.assertEqual(cliapp.runcmd_unchecked(
+                            ['echo', 'foo'], ['wc', '-c']),
+                         (0, '4\n', ''))
+
+    def test_runcmd_unchecked_runs_longer_pipeline(self):
+        self.assertEqual(cliapp.runcmd_unchecked(['echo', 'foo'],
+                                                 ['cat'],
+                                                 ['wc', '-c']),
+                         (0, '4\n', ''))
+
+    def test_runcmd_redirects_stdin_from_file(self):
+        fd, filename = tempfile.mkstemp()
+        os.write(fd, 'foobar')
+        os.lseek(fd, 0, os.SEEK_SET)
+        self.assertEqual(cliapp.runcmd_unchecked(['cat'], stdin=fd),
+                         (0, 'foobar', ''))
+        os.close(fd)
+
+    def test_runcmd_redirects_stdout_to_file(self):
+        fd, filename = tempfile.mkstemp()
+        exit, out, err = cliapp.runcmd_unchecked(['echo', 'foo'], stdout=fd)
+        os.close(fd)
+        with open(filename) as f:
+            data = f.read()
+        self.assertEqual(exit, 0)
+        self.assertEqual(data, 'foo\n')
+
+    def test_runcmd_redirects_stderr_to_file(self):
+        fd, filename = tempfile.mkstemp()
+        exit, out, err = cliapp.runcmd_unchecked(['ls', 'notexist'], stderr=fd)
+        os.close(fd)
+        with open(filename) as f:
+            data = f.read()
+        self.assertNotEqual(exit, 0)
+        self.assertNotEqual(data, '')
+
+    def test_runcmd_unchecked_handles_stdout_err_redirected_to_same_file(self):
+        fd, filename = tempfile.mkstemp()
+        exit, out, err = cliapp.runcmd_unchecked(['sleep', '2'],
+                                                 stdout=fd,
+                                                 stderr=subprocess.STDOUT)
+        os.close(fd)
+        with open(filename) as f:
+            data = f.read()
+        self.assertEqual(exit, 0)
+        self.assertEqual(data, '')
+
+
+class ShellQuoteTests(unittest.TestCase):
+
+    def test_returns_empty_string_for_empty_string(self):
+        self.assertEqual(cliapp.shell_quote(''), '')
+
+    def test_returns_same_string_when_safe(self):
+        self.assertEqual(cliapp.shell_quote('abc123'), 'abc123')
+
+    def test_quotes_space(self):
+        self.assertEqual(cliapp.shell_quote(' '), "' '")
+
+    def test_quotes_double_quote(self):
+        self.assertEqual(cliapp.shell_quote('"'), "'\"'")
+
+    def test_quotes_single_quote(self):
+        self.assertEqual(cliapp.shell_quote("'"), '"\'"')
+
diff --git a/cliapp/settings.py b/cliapp/settings.py
new file mode 100644
index 00000000..b2d0abb0
--- /dev/null
+++ b/cliapp/settings.py
@@ -0,0 +1,772 @@
+# Copyright (C) 2009-2012  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import ConfigParser
+import optparse
+import os
+import re
+import sys
+
+import cliapp
+from cliapp.genman import ManpageGenerator
+
+
+log_group_name = 'Logging'
+config_group_name = 'Configuration files and settings'
+perf_group_name = 'Peformance'
+
+default_group_names = [
+    log_group_name,
+    config_group_name,
+    perf_group_name,
+]
+
+
+class Setting(object):
+
+    action = 'store'
+    type = 'string'
+    nargs = 1
+    choices = None
+
+    def __init__(
+        self, names, default, help, metavar=None, group=None, hidden=False):
+        self.names = names
+        self.set_value(default)
+        self.help = help
+        self.metavar = metavar or self.default_metavar()
+        self.group = group
+        self.hidden = hidden
+
+    def default_metavar(self):
+        return None
+
+    def get_value(self):
+        return self._string_value
+
+    def set_value(self, value):
+        self._string_value = value
+
+    def call_get_value(self):
+        return self.get_value()
+
+    def call_set_value(self, value):
+        self.set_value(value)
+
+    value = property(call_get_value, call_set_value)
+
+    def has_value(self):
+        return self.value is not None
+
+    def parse_value(self, string):
+        self.value = string
+
+    def format(self): # pragma: no cover
+        return str(self.value)
+
+
+class StringSetting(Setting):
+
+    def default_metavar(self):
+        return self.names[0].upper()
+
+
+class StringListSetting(Setting):
+
+    action = 'append'
+
+    def __init__(
+        self, names, default, help, metavar=None, group=None, hidden=False):
+        Setting.__init__(
+            self, names, [], help, metavar=metavar, group=group, hidden=hidden)
+        self.default = default
+        self.using_default_value = True
+
+    def default_metavar(self):
+        return self.names[0].upper()
+
+    def get_value(self):
+        if self._string_value.strip():
+            return [s.strip() for s in self._string_value.split(',')]
+        else:
+            return self.default
+
+    def set_value(self, strings):
+        self._string_value = ','.join(strings)
+        self.using_default_value = False
+
+    def has_value(self):
+        return self.value != []
+
+    def parse_value(self, string):
+        self.value = [s.strip() for s in string.split(',')]
+
+    def format(self): # pragma: no cover
+        return ', '.join(self.value)
+
+
+class ChoiceSetting(Setting):
+
+    type = 'choice'
+
+    def __init__(
+        self, names, choices, help, metavar=None, group=None, hidden=False):
+        Setting.__init__(
+            self, names, choices[0], help, metavar=metavar, group=group,
+            hidden=hidden)
+        self.choices = choices
+
+    def default_metavar(self):
+        return self.names[0].upper()
+
+
+class BooleanSetting(Setting):
+
+    action = 'store_true'
+    nargs = None
+    type = None
+
+    _trues = ['yes', 'on', '1', 'true']
+    _false = 'no'
+
+    def get_value(self):
+        return self._string_value.lower() in self._trues
+
+    def set_value(self, value):
+        def is_true():
+            if value is True or value is False:
+                return value
+            if type(value) in [str, unicode]:
+                return value.lower() in self._trues
+            return value
+        if is_true():
+            self._string_value = self._trues[0]
+        else:
+            self._string_value = self._false
+
+
+class ByteSizeSetting(Setting):
+
+    def parse_human_size(self, size):
+        '''Parse a size using suffix into plain bytes.'''
+
+        m = re.match(r'''(?P<number>\d+(\.\d+)?) \s*
+                         (?P<unit>k|ki|m|mi|g|gi|t|ti)? b? \s*$''',
+                     size.lower(), flags=re.X)
+        if not m:
+            return 0
+        else:
+            number = float(m.group('number'))
+            unit = m.group('unit')
+            units = {
+                'k': 10**3,
+                'm': 10**6,
+                'g': 10**9,
+                't': 10**12,
+                'ki': 2**10,
+                'mi': 2**20,
+                'gi': 2**30,
+                'ti': 2**40,
+            }
+            return long(number * units.get(unit, 1))
+
+    def default_metavar(self):
+        return 'SIZE'
+
+    def get_value(self):
+        return long(self._string_value)
+
+    def set_value(self, value):
+        if type(value) == str:
+            value = self.parse_human_size(value)
+        self._string_value = str(value)
+
+
+class IntegerSetting(Setting):
+
+    type = 'int'
+
+    def default_metavar(self):
+        return self.names[0].upper()
+
+    def get_value(self):
+        return long(self._string_value)
+
+    def set_value(self, value):
+        self._string_value = str(value)
+
+
+class FormatHelpParagraphs(optparse.IndentedHelpFormatter):
+
+    def _format_text(self, text): # pragma: no cover
+        '''Like the default, except handle paragraphs.'''
+
+        fmt = cliapp.TextFormat(width=self.width)
+        formatted = fmt.format(text)
+        return formatted.rstrip('\n')
+
+
+class Settings(object):
+
+    '''Settings for a cliapp application.
+
+    You probably don't need to create a settings object yourself,
+    since ``cliapp.Application`` does it for you.
+
+    Settings are read from configuration files, and parsed from the
+    command line. Every setting has a type, name, and help text,
+    and may have a default value as well.
+
+    For example::
+
+        settings.boolean(['verbose', 'v'], 'show what is going on')
+
+    This would create a new setting, ``verbose``, with a shorter alias
+    ``v``. On the command line, the options ``--verbose`` and
+    ``-v`` would work equally well. There can be any number of aliases.
+
+    The help text is shown if the user uses ``--help`` or
+    ``--generate-manpage``.
+    You can use the ``metavar`` keyword argument to set the name shown
+    in the generated option lists; the default name is whatever
+    ``optparse`` decides (i.e., name of option).
+
+    Use ``load_configs`` to read configuration files, and
+    ``parse_args`` to parse command line arguments.
+
+    The current value of a setting can be accessed by indexing
+    the settings class::
+
+        settings['verbose']
+
+    The list of configuration files for the appliation is stored
+    in ``config_files``. Add or remove from the list if you wish.
+    The files need to exist: those that don't are silently ignored.
+
+    '''
+
+    def __init__(self, progname, version, usage=None, description=None,
+                 epilog=None):
+        self._settingses = dict()
+        self._canonical_names = list()
+
+        self.version = version
+        self.progname = progname
+        self.usage = usage
+        self.description = description
+        self.epilog = epilog
+
+        self._add_default_settings()
+
+        self._config_files = None
+        self._cp = ConfigParser.ConfigParser()
+
+    def _add_default_settings(self):
+        self.string(['output'],
+                    'write output to FILE, instead of standard output',
+                    metavar='FILE')
+
+        self.string(['log'],
+                    'write log entries to FILE (default is to not write log '
+                        'files at all); use "syslog" to log to system log, '
+                        'or "none" to disable logging',
+                    metavar='FILE', group=log_group_name)
+        self.choice(['log-level'],
+                    ['debug', 'info', 'warning', 'error', 'critical', 'fatal'],
+                    'log at LEVEL, one of debug, info, warning, '
+                        'error, critical, fatal (default: %default)',
+                    metavar='LEVEL', group=log_group_name)
+        self.bytesize(['log-max'],
+                      'rotate logs larger than SIZE, '
+                        'zero for never (default: %default)',
+                      metavar='SIZE', default=0, group=log_group_name)
+        self.integer(['log-keep'], 'keep last N logs (%default)',
+                     metavar='N', default=10, group=log_group_name)
+        self.string(['log-mode'],
+                    'set permissions of new log files to MODE (octal; '
+                        'default %default)',
+                    metavar='MODE', default='0600', group=log_group_name)
+
+        self.choice(['dump-memory-profile'],
+                    ['simple', 'none', 'meliae', 'heapy'],
+                    'make memory profiling dumps using METHOD, which is one '
+                        'of: none, simple, meliae, or heapy '
+                        '(default: %default)',
+                    metavar='METHOD',
+                    group=perf_group_name)
+        self.integer(['memory-dump-interval'],
+                     'make memory profiling dumps at least SECONDS apart',
+                     metavar='SECONDS',
+                     default=300,
+                     group=perf_group_name)
+
+    def _add_setting(self, setting):
+        '''Add a setting to self._cp.'''
+
+        self._canonical_names.append(setting.names[0])
+        for name in setting.names:
+            self._settingses[name] = setting
+
+    def string(self, names, help, default='', **kwargs):
+        '''Add a setting with a string value.'''
+        self._add_setting(StringSetting(names, default, help, **kwargs))
+
+    def string_list(self, names, help, default=None, **kwargs):
+        '''Add a setting which have multiple string values.
+
+        An example would be an option that can be given multiple times
+        on the command line, e.g., "--exclude=foo --exclude=bar".
+
+        '''
+
+        self._add_setting(StringListSetting(names, default or [], help,
+                                            **kwargs))
+
+    def choice(self, names, possibilities, help, **kwargs):
+        '''Add a setting which chooses from list of acceptable values.
+
+        An example would be an option to set debugging level to be
+        one of a set of accepted names: debug, info, warning, etc.
+
+        The default value is the first possibility.
+
+        '''
+
+        self._add_setting(ChoiceSetting(names, possibilities, help, **kwargs))
+
+    def boolean(self, names, help, default=False, **kwargs):
+        '''Add a setting with a boolean value.'''
+        self._add_setting(BooleanSetting(names, default, help, **kwargs))
+
+    def bytesize(self, names, help, default=0, **kwargs):
+        '''Add a setting with a size in bytes.
+
+        The user can use suffixes for kilo/mega/giga/tera/kibi/mibi/gibi/tibi.
+
+        '''
+
+        self._add_setting(ByteSizeSetting(names, default, help, **kwargs))
+
+    def integer(self, names, help, default=0, **kwargs):
+        '''Add an integer setting.'''
+        self._add_setting(IntegerSetting(names, default, help, **kwargs))
+
+    def __getitem__(self, name):
+        return self._settingses[name].value
+
+    def __setitem__(self, name, value):
+        self._settingses[name].value = value
+
+    def __contains__(self, name):
+        return name in self._settingses
+
+    def __iter__(self):
+        '''Iterate over canonical settings names.'''
+        for name in self._canonical_names:
+            yield name
+
+    def keys(self):
+        '''Return canonical settings names.'''
+        return self._canonical_names[:]
+
+    def require(self, name):
+        '''Raise exception if setting has not been set.
+
+        Option must have a value, and a default value is OK.
+
+        '''
+
+        if not self._settingses[name].has_value():
+            raise cliapp.AppException('Setting %s has no value, '
+                                        'but one is required' % name)
+
+    def _option_names(self, names):
+        '''Turn setting names into option names.
+
+        Names with a single letter are short options, and get prefixed
+        with one dash. The rest get prefixed with two dashes.
+
+        '''
+
+        return ['--%s' % name if len(name) > 1 else '-%s' % name
+                for name in names]
+
+    def _destname(self, name):
+        name = '_'.join(name.split('-'))
+        return name
+
+    def build_parser(self, configs_only=False, arg_synopsis=None,
+                     cmd_synopsis=None, deferred_last=[], all_options=False,
+                     add_help_option=True):
+        '''Build OptionParser for parsing command line.'''
+
+        # Call a callback function unless we're in configs_only mode.
+        maybe = lambda func: (lambda *args: None) if configs_only else func
+
+
+        # Maintain lists of callback function calls that are deferred.
+        # We call them ourselves rather than have OptionParser call them
+        # directly so that we can do things like --dump-config only
+        # after the whole command line is parsed.
+
+        def defer_last(func): # pragma: no cover
+            def callback(*args):
+                deferred_last.append(lambda: func(*args))
+            return callback
+
+        # Create the command line parser.
+
+        def getit(x):
+            if x is None or type(x) in [str, unicode]:
+                return x
+            else:
+                return x()
+        usage = getit(self.usage)
+        description = getit(self.description)
+        p = optparse.OptionParser(prog=self.progname, version=self.version,
+                                  formatter=FormatHelpParagraphs(),
+                                  usage=usage,
+                                  description=description,
+                                  epilog=self.epilog,
+                                  add_help_option=add_help_option)
+
+        # Create all OptionGroup objects. This way, the user code can
+        # add settings to built-in option groups.
+
+        group_names = set(default_group_names)
+        for name in self._canonical_names:
+            s = self._settingses[name]
+            if s.group is not None:
+                group_names.add(s.group)
+        group_names = sorted(group_names)
+
+        option_groups = {}
+        for name in group_names:
+            group = optparse.OptionGroup(p, name)
+            p.add_option_group(group)
+            option_groups[name] = group
+
+        config_group = option_groups[config_group_name]
+
+        # Return help text, unless setting/option is hidden, in which
+        # case return optparse.SUPPRESS_HELP.
+
+        def help_text(text, hidden):
+            if all_options or not hidden:
+                return text
+            else:
+                return optparse.SUPPRESS_HELP
+
+        # Add --dump-setting-names.
+
+        def dump_setting_names(*args): # pragma: no cover
+            for name in self._canonical_names:
+                sys.stdout.write('%s\n' % name)
+            sys.exit(0)
+
+        config_group.add_option('--dump-setting-names',
+                     action='callback',
+                     nargs=0,
+                     callback=defer_last(maybe(dump_setting_names)),
+                     help=help_text(
+                        'write out all names of settings and quit', True))
+
+        # Add --dump-config.
+
+        def call_dump_config(*args): # pragma: no cover
+            self.dump_config(sys.stdout)
+            sys.exit(0)
+
+        config_group.add_option('--dump-config',
+                     action='callback',
+                     nargs=0,
+                     callback=defer_last(maybe(call_dump_config)),
+                     help='write out the entire current configuration')
+
+        # Add --no-default-configs.
+
+        def reset_configs(option, opt_str, value, parser):
+            self.config_files = []
+
+        config_group.add_option('--no-default-configs',
+                     action='callback',
+                     nargs=0,
+                     callback=reset_configs,
+                     help='clear list of configuration files to read')
+
+        # Add --config.
+
+        def append_to_configs(option, opt_str, value, parser):
+            self.config_files.append(value)
+
+        config_group.add_option('--config',
+                     action='callback',
+                     nargs=1,
+                     type='string',
+                     callback=append_to_configs,
+                     help='add FILE to config files',
+                     metavar='FILE')
+
+        # Add --list-config-files.
+
+        def list_config_files(*args): # pragma: no cover
+            for filename in self.config_files:
+                print filename
+            sys.exit(0)
+
+        config_group.add_option('--list-config-files',
+                     action='callback',
+                     nargs=0,
+                     callback=defer_last(maybe(list_config_files)),
+                     help=help_text('list all possible config files', True))
+
+        # Add --generate-manpage.
+
+        self._arg_synopsis = arg_synopsis
+        self._cmd_synopsis = cmd_synopsis
+        p.add_option('--generate-manpage',
+                     action='callback',
+                     nargs=1,
+                     type='string',
+                     callback=maybe(self._generate_manpage),
+                     help=help_text('fill in manual page TEMPLATE', True),
+                     metavar='TEMPLATE')
+
+        # Add --help-all.
+
+        def help_all(*args): # pragma: no cover
+            pp = self.build_parser(
+                configs_only=configs_only,
+                arg_synopsis=arg_synopsis,
+                cmd_synopsis=cmd_synopsis,
+                all_options=True)
+            sys.stdout.write(pp.format_help())
+            sys.exit(0)
+
+        if add_help_option:
+            config_group.add_option(
+                '--help-all',
+                action='callback',
+                help='show all options',
+                callback=defer_last(maybe(help_all)))
+
+        # Add other options, from the user-defined and built-in
+        # settingses.
+
+        def set_value(option, opt_str, value, parser, setting):
+            if setting.action == 'append':
+                if setting.using_default_value:
+                    setting.value = [value]
+                else:
+                    setting.value += [value]
+            elif setting.action == 'store_true':
+                setting.value = True
+            else:
+                assert setting.action == 'store'
+                setting.value = value
+
+        def set_false(option, opt_str, value, parser, setting):
+            setting.value = False
+
+        def add_option(obj, s):
+            option_names = self._option_names(s.names)
+            obj.add_option(*option_names,
+                           action='callback',
+                           callback=maybe(set_value),
+                           callback_args=(s,),
+                           type=s.type,
+                           nargs=s.nargs,
+                           choices=s.choices,
+                           help=help_text(s.help, s.hidden),
+                           metavar=s.metavar)
+
+        def add_negation_option(obj, s):
+            option_names = self._option_names(s.names)
+            long_names = [x for x in option_names if x.startswith('--')]
+            neg_names = ['--no-' + x[2:] for x in long_names]
+            unused_names = [x for x in neg_names
+                            if x[2:] not in self._settingses]
+            obj.add_option(*unused_names,
+                           action='callback',
+                           callback=maybe(set_false),
+                           callback_args=(s,),
+                           type=s.type,
+                           help=help_text('', s.hidden))
+
+        # Add options for every setting.
+
+        for name in self._canonical_names:
+            s = self._settingses[name]
+            if s.group is None:
+                obj = p
+            else:
+                obj = option_groups[s.group]
+
+            add_option(obj, s)
+            if type(s) is BooleanSetting:
+                add_negation_option(obj, s)
+            p.set_defaults(**{self._destname(name): s.value})
+
+        return p
+
+    def parse_args(self, args, parser=None, suppress_errors=False,
+                    configs_only=False, arg_synopsis=None,
+                    cmd_synopsis=None, compute_setting_values=None,
+                    all_options=False, add_help_option=True):
+        '''Parse the command line.
+
+        Return list of non-option arguments. ``args`` would usually
+        be ``sys.argv[1:]``.
+
+        '''
+
+        deferred_last = []
+
+        p = parser or self.build_parser(configs_only=configs_only,
+                                        arg_synopsis=arg_synopsis,
+                                        cmd_synopsis=cmd_synopsis,
+                                        deferred_last=deferred_last,
+                                        all_options=all_options,
+                                        add_help_option=add_help_option)
+
+        if suppress_errors:
+            p.error = lambda msg: sys.exit(1)
+
+        options, args = p.parse_args(args)
+        if compute_setting_values: # pragma: no cover
+            compute_setting_values(self)
+        for callback in deferred_last: # pragma: no cover
+            callback()
+        return args
+
+    @property
+    def _default_config_files(self):
+        '''Return list of default config files to read.
+
+        The names of the files are dependent on the name of the program,
+        as set in the progname attribute.
+
+        The files may or may not exist.
+
+        '''
+
+        configs = []
+
+        configs.append('/etc/%s.conf' % self.progname)
+        configs += self._listconfs('/etc/%s' % self.progname)
+        configs.append(os.path.expanduser('~/.%s.conf' % self.progname))
+        configs += self._listconfs(
+                        os.path.expanduser('~/.config/%s' % self.progname))
+
+        return configs
+
+    def _listconfs(self, dirname, listdir=os.listdir):
+        '''Return list of pathnames to config files in dirname.
+
+        Config files are expectd to have names ending in '.conf'.
+
+        If dirname does not exist or is not a directory,
+        return empty list.
+
+        '''
+
+        if not os.path.isdir(dirname):
+            return []
+
+        basenames = listdir(dirname)
+        basenames.sort(key=lambda s: [ord(c) for c in s])
+        return [os.path.join(dirname, x)
+                for x in basenames
+                if x.endswith('.conf')]
+
+    def _get_config_files(self):
+        if self._config_files is None:
+            self._config_files = self._default_config_files
+        return self._config_files
+
+    def _set_config_files(self, config_files):
+        self._config_files = config_files
+
+    config_files = property(_get_config_files, _set_config_files)
+
+    def set_from_raw_string(self, name, raw_string):
+        '''Set value of a setting from a raw, unparsed string value.'''
+        s = self._settingses[name]
+        s.parse_value(raw_string)
+        return s
+
+    def load_configs(self, open=open):
+        '''Load all config files in self.config_files.
+
+        Silently ignore files that do not exist.
+
+        '''
+
+        cp = ConfigParser.ConfigParser()
+        cp.add_section('config')
+
+        for pathname in self.config_files:
+            try:
+                f = open(pathname)
+            except IOError:
+                pass
+            else:
+                cp.readfp(f)
+                f.close()
+
+        for name in cp.options('config'):
+            value = cp.get('config', name)
+            s = self.set_from_raw_string(name, value)
+            if hasattr(s, 'using_default_value'):
+                s.using_default_value = True
+
+        # Remember the ConfigParser for use in as_cp later on.
+        self._cp = cp
+
+    def _generate_manpage(self, o, os, value, p): # pragma: no cover
+        template = open(value).read()
+        generator = ManpageGenerator(template, p, self._arg_synopsis,
+                                     self._cmd_synopsis)
+        sys.stdout.write(generator.format_template())
+        sys.exit(0)
+
+    def as_cp(self):
+        '''Return a ConfigParser instance with current values of settings.
+
+        Any sections outside of ``[config]`` are preserved as is. This
+        lets the application use those as it wishes, and assign any
+        meanings it desires to the section names.
+
+        '''
+        cp = ConfigParser.ConfigParser()
+        cp.add_section('config')
+        for name in self._canonical_names:
+            cp.set('config', name, self._settingses[name].format())
+
+        for section in self._cp.sections():
+            if section != 'config':
+                cp.add_section(section)
+                for option in self._cp.options(section):
+                    value = self._cp.get(section, option)
+                    cp.set(section, option, value)
+
+        return cp
+
+    def dump_config(self, output): # pragma: no cover
+        cp = self.as_cp()
+        cp.write(output)
+
diff --git a/cliapp/settings_tests.py b/cliapp/settings_tests.py
new file mode 100644
index 00000000..7a44d813
--- /dev/null
+++ b/cliapp/settings_tests.py
@@ -0,0 +1,429 @@
+# Copyright (C) 2009-2012  Lars Wirzenius
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import optparse
+import StringIO
+import sys
+import unittest
+
+import cliapp
+
+
+class SettingsTests(unittest.TestCase):
+
+    def setUp(self):
+        self.settings = cliapp.Settings('appname', '1.0')
+
+    def test_has_progname(self):
+        self.assertEqual(self.settings.progname, 'appname')
+
+    def test_sets_progname(self):
+        self.settings.progname = 'foo'
+        self.assertEqual(self.settings.progname, 'foo')
+
+    def test_has_version(self):
+        self.assertEqual(self.settings.version, '1.0')
+
+    def test_sets_usage_from_func(self):
+        s = cliapp.Settings('appname', '1.0', usage=lambda: 'xyzzy')
+        p = s.build_parser()
+        self.assert_('xyzzy' in p.usage)
+
+    def test_adds_default_options_and_settings(self):
+        self.assert_('output' in self.settings)
+        self.assert_('log' in self.settings)
+        self.assert_('log-level' in self.settings)
+
+    def test_iterates_over_canonical_settings_names(self):
+        known = ['output', 'log', 'log-level']
+        self.assertEqual(sorted(x for x in self.settings if x in known),
+                         sorted(known))
+
+    def test_keys_returns_canonical_names(self):
+        known = ['output', 'log', 'log-level']
+        self.assertEqual(sorted(x for x in self.settings.keys() if x in known),
+                         sorted(known))
+
+    def test_parses_options(self):
+        self.settings.string(['foo'], 'foo help', group='foo')
+        self.settings.boolean(['bar'], 'bar help')
+        self.settings.parse_args(['--foo=foovalue', '--bar'])
+        self.assertEqual(self.settings['foo'], 'foovalue')
+        self.assertEqual(self.settings['bar'], True)
+
+    def test_parses_boolean_negation_option(self):
+        self.settings.boolean(['bar'], 'bar help')
+        self.settings.parse_args(['--bar', '--no-bar'])
+        self.assertEqual(self.settings['bar'], False)
+
+    def test_parses_boolean_negation_option_in_group(self):
+        self.settings.boolean(['bar'], 'bar help', group='bar')
+        self.settings.parse_args(['--bar', '--no-bar'])
+        self.assertEqual(self.settings['bar'], False)
+
+    def test_does_not_have_foo_setting_by_default(self):
+        self.assertFalse('foo' in self.settings)
+
+    def test_raises_keyerror_for_getting_unknown_setting(self):
+        self.assertRaises(KeyError, self.settings.__getitem__, 'foo')
+
+    def test_raises_keyerror_for_setting_unknown_setting(self):
+        self.assertRaises(KeyError, self.settings.__setitem__, 'foo', 'bar')
+
+    def test_adds_string_setting(self):
+        self.settings.string(['foo'], 'foo help')
+        self.assert_('foo' in self.settings)
+
+    def test_adds_string_list_setting(self):
+        self.settings.string_list(['foo'], 'foo help')
+        self.assert_('foo' in self.settings)
+
+    def test_string_list_is_empty_list_by_default(self):
+        self.settings.string_list(['foo'], '')
+        self.settings.parse_args([])
+        self.assertEqual(self.settings['foo'], [])
+
+    def test_string_list_parses_one_item(self):
+        self.settings.string_list(['foo'], '')
+        self.settings.parse_args(['--foo=foo'])
+        self.assertEqual(self.settings['foo'], ['foo'])
+
+    def test_string_list_parses_two_items(self):
+        self.settings.string_list(['foo'], '')
+        self.settings.parse_args(['--foo=foo', '--foo', 'bar'])
+        self.assertEqual(self.settings['foo'], ['foo', 'bar'])
+
+    def test_string_list_uses_nonempty_default_if_given(self):
+        self.settings.string_list(['foo'], '', default=['bar'])
+        self.settings.parse_args([])
+        self.assertEqual(self.settings['foo'], ['bar'])
+
+    def test_string_list_uses_ignores_default_if_user_provides_values(self):
+        self.settings.string_list(['foo'], '', default=['bar'])
+        self.settings.parse_args(['--foo=pink', '--foo=punk'])
+        self.assertEqual(self.settings['foo'], ['pink', 'punk'])
+
+    def test_adds_choice_setting(self):
+        self.settings.choice(['foo'], ['foo', 'bar'], 'foo help')
+        self.assert_('foo' in self.settings)
+
+    def test_choice_defaults_to_first_one(self):
+        self.settings.choice(['foo'], ['foo', 'bar'], 'foo help')
+        self.settings.parse_args([])
+        self.assertEqual(self.settings['foo'], 'foo')
+
+    def test_choice_accepts_any_valid_value(self):
+        self.settings.choice(['foo'], ['foo', 'bar'], 'foo help')
+        self.settings.parse_args(['--foo=foo'])
+        self.assertEqual(self.settings['foo'], 'foo')
+        self.settings.parse_args(['--foo=bar'])
+        self.assertEqual(self.settings['foo'], 'bar')
+
+    def test_choice_raises_error_for_unacceptable_value(self):
+        self.settings.choice(['foo'], ['foo', 'bar'], 'foo help')
+        self.assertRaises(SystemExit,
+                          self.settings.parse_args, ['--foo=xyzzy'],
+                          suppress_errors=True)
+
+    def test_adds_boolean_setting(self):
+        self.settings.boolean(['foo'], 'foo help')
+        self.assert_('foo' in self.settings)
+
+    def test_boolean_setting_is_false_by_default(self):
+        self.settings.boolean(['foo'], 'foo help')
+        self.assertFalse(self.settings['foo'])
+
+    def test_sets_boolean_setting_to_true_for_many_true_values(self):
+        self.settings.boolean(['foo'], 'foo help')
+        self.settings['foo'] = True
+        self.assert_(self.settings['foo'])
+        self.settings['foo'] = 1
+        self.assert_(self.settings['foo'])
+
+    def test_sets_boolean_setting_to_false_for_many_false_values(self):
+        self.settings.boolean(['foo'], 'foo help')
+        self.settings['foo'] = False
+        self.assertFalse(self.settings['foo'])
+        self.settings['foo'] = 0
+        self.assertFalse(self.settings['foo'])
+        self.settings['foo'] = ()
+        self.assertFalse(self.settings['foo'])
+        self.settings['foo'] = []
+        self.assertFalse(self.settings['foo'])
+        self.settings['foo'] = ''
+        self.assertFalse(self.settings['foo'])
+
+    def test_sets_boolean_to_true_from_config_file(self):
+        def fake_open(filename):
+            return StringIO.StringIO('[config]\nfoo = yes\n')
+        self.settings.boolean(['foo'], 'foo help')
+        self.settings.load_configs(open=fake_open)
+        self.assertEqual(self.settings['foo'], True)
+
+    def test_sets_boolean_to_false_from_config_file(self):
+        def fake_open(filename):
+            return StringIO.StringIO('[config]\nfoo = False\n')
+        self.settings.boolean(['foo'], 'foo help')
+        self.settings.load_configs(open=fake_open)
+        self.assertEqual(self.settings['foo'], False)
+
+    def test_adds_bytesize_setting(self):
+        self.settings.bytesize(['foo'], 'foo help')
+        self.assert_('foo' in self.settings)
+
+    def test_parses_bytesize_option(self):
+        self.settings.bytesize(['foo'], 'foo help')
+
+        self.settings.parse_args(args=['--foo=xyzzy'])
+        self.assertEqual(self.settings['foo'], 0)
+
+        self.settings.parse_args(args=['--foo=123'])
+        self.assertEqual(self.settings['foo'], 123)
+
+        self.settings.parse_args(args=['--foo=123k'])
+        self.assertEqual(self.settings['foo'], 123 * 1000)
+
+        self.settings.parse_args(args=['--foo=123m'])
+        self.assertEqual(self.settings['foo'], 123 * 1000**2)
+
+        self.settings.parse_args(args=['--foo=123g'])
+        self.assertEqual(self.settings['foo'], 123 * 1000**3)
+
+        self.settings.parse_args(args=['--foo=123t'])
+        self.assertEqual(self.settings['foo'], 123 * 1000**4)
+
+        self.settings.parse_args(args=['--foo=123kib'])
+        self.assertEqual(self.settings['foo'], 123 * 1024)
+
+        self.settings.parse_args(args=['--foo=123mib'])
+        self.assertEqual(self.settings['foo'], 123 * 1024**2)
+
+        self.settings.parse_args(args=['--foo=123gib'])
+        self.assertEqual(self.settings['foo'], 123 * 1024**3)
+
+        self.settings.parse_args(args=['--foo=123tib'])
+        self.assertEqual(self.settings['foo'], 123 * 1024**4)
+
+    def test_adds_integer_setting(self):
+        self.settings.integer(['foo'], 'foo help')
+        self.assert_('foo' in self.settings)
+
+    def test_parses_integer_option(self):
+        self.settings.integer(['foo'], 'foo help', default=123)
+
+        self.settings.parse_args(args=[])
+        self.assertEqual(self.settings['foo'], 123)
+
+        self.settings.parse_args(args=['--foo=123'])
+        self.assertEqual(self.settings['foo'], 123)
+
+    def test_has_list_of_default_config_files(self):
+        defaults = self.settings._default_config_files
+        self.assert_(isinstance(defaults, list))
+        self.assert_(len(defaults) > 0)
+
+    def test_listconfs_returns_empty_list_for_nonexistent_directory(self):
+        self.assertEqual(self.settings._listconfs('notexist'), [])
+
+    def test_listconfs_lists_config_files_only(self):
+        def mock_listdir(dirname):
+            return ['foo.conf', 'foo.notconf']
+        names = self.settings._listconfs('.', listdir=mock_listdir)
+        self.assertEqual(names, ['./foo.conf'])
+
+    def test_listconfs_sorts_names_in_C_locale(self):
+        def mock_listdir(dirname):
+            return ['foo.conf', 'bar.conf']
+        names = self.settings._listconfs('.', listdir=mock_listdir)
+        self.assertEqual(names, ['./bar.conf', './foo.conf'])
+
+    def test_has_config_files_attribute(self):
+        self.assertEqual(self.settings.config_files,
+                         self.settings._default_config_files)
+
+    def test_has_config_files_list_can_be_changed(self):
+        self.settings.config_files += ['./foo']
+        self.assertEqual(self.settings.config_files,
+                         self.settings._default_config_files + ['./foo'])
+
+    def test_loads_config_files(self):
+
+        def mock_open(filename, mode=None):
+            return StringIO.StringIO('''\
+[config]
+foo = yeehaa
+''')
+
+        self.settings.string(['foo'], 'foo help')
+        self.settings.config_files = ['whatever.conf']
+        self.settings.load_configs(open=mock_open)
+        self.assertEqual(self.settings['foo'], 'yeehaa')
+
+    def test_loads_string_list_from_config_files(self):
+
+        def mock_open(filename, mode=None):
+            return StringIO.StringIO('''\
+[config]
+foo = yeehaa
+bar = ping, pong
+''')
+
+        self.settings.string_list(['foo'], 'foo help')
+        self.settings.string_list(['bar'], 'bar help')
+        self.settings.config_files = ['whatever.conf']
+        self.settings.load_configs(open=mock_open)
+        self.assertEqual(self.settings['foo'], ['yeehaa'])
+        self.assertEqual(self.settings['bar'], ['ping', 'pong'])
+
+    def test_handles_defaults_with_config_files(self):
+
+        def mock_open(filename, mode=None):
+            return StringIO.StringIO('''\
+[config]
+''')
+
+        self.settings.string(['foo'], 'foo help', default='foo')
+        self.settings.string_list(['bar'], 'bar help', default=['bar'])
+        self.settings.config_files = ['whatever.conf']
+        self.settings.load_configs(open=mock_open)
+        self.assertEqual(self.settings['foo'], 'foo')
+        self.assertEqual(self.settings['bar'], ['bar'])
+
+    def test_handles_overridden_defaults_with_config_files(self):
+
+        def mock_open(filename, mode=None):
+            return StringIO.StringIO('''\
+[config]
+foo = yeehaa
+bar = ping, pong
+''')
+
+        self.settings.string(['foo'], 'foo help', default='foo')
+        self.settings.string_list(['bar'], 'bar help', default=['bar'])
+        self.settings.config_files = ['whatever.conf']
+        self.settings.load_configs(open=mock_open)
+        self.assertEqual(self.settings['foo'], 'yeehaa')
+        self.assertEqual(self.settings['bar'], ['ping', 'pong'])
+
+    def test_handles_values_from_config_files_overridden_on_command_line(self):
+
+        def mock_open(filename, mode=None):
+            return StringIO.StringIO('''\
+[config]
+foo = yeehaa
+bar = ping, pong
+''')
+
+        self.settings.string(['foo'], 'foo help', default='foo')
+        self.settings.string_list(['bar'], 'bar help', default=['bar'])
+        self.settings.config_files = ['whatever.conf']
+        self.settings.load_configs(open=mock_open)
+        self.settings.parse_args(['--foo=red', '--bar=blue', '--bar=white'])
+        self.assertEqual(self.settings['foo'], 'red')
+        self.assertEqual(self.settings['bar'], ['blue', 'white'])
+
+    def test_load_configs_ignore_errors_opening_a_file(self):
+
+        def mock_open(filename, mode=None):
+            raise IOError()
+
+        self.assertEqual(self.settings.load_configs(open=mock_open), None)
+
+    def test_adds_config_file_with_dash_dash_config(self):
+        self.settings.parse_args(['--config=foo.conf'])
+        self.assertEqual(self.settings.config_files,
+                         self.settings._default_config_files + ['foo.conf'])
+
+    def test_ignores_default_configs(self):
+        self.settings.parse_args(['--no-default-configs'])
+        self.assertEqual(self.settings.config_files, [])
+
+    def test_ignores_then_adds_configs_works(self):
+        self.settings.parse_args(['--no-default-configs', '--config=foo.conf'])
+        self.assertEqual(self.settings.config_files, ['foo.conf'])
+
+    def test_require_raises_error_if_string_unset(self):
+        self.settings.string(['foo'], 'foo help', default=None)
+        self.assertRaises(cliapp.AppException, self.settings.require,
+                          'foo')
+
+    def test_require_is_ok_with_set_string(self):
+        self.settings.string(['foo'], 'foo help', default=None)
+        self.settings['foo'] = 'bar'
+        self.assertEqual(self.settings.require('foo'), None)
+
+    def test_require_is_ok_with_default_string(self):
+        self.settings.string(['foo'], 'foo help', default='foo default')
+        self.assertEqual(self.settings.require('foo'), None)
+
+    def test_require_raises_error_if_string_list_unset(self):
+        self.settings.string_list(['foo'], 'foo help')
+        self.assertRaises(cliapp.AppException, self.settings.require, 'foo')
+
+    def test_require_is_ok_with_set_string_list(self):
+        self.settings.string(['foo'], 'foo help')
+        self.settings['foo'] = ['foo', 'bar']
+        self.assertEqual(self.settings.require('foo'), None)
+
+    def test_require_is_ok_with_default_string_list(self):
+        self.settings.string(['foo'], 'foo help', default=['foo'])
+        self.assertEqual(self.settings.require('foo'), None)
+
+    def test_require_is_ok_with_unset_choice(self):
+        self.settings.choice(['foo'], ['foo', 'bar'], 'foo help')
+        self.assertEqual(self.settings.require('foo'), None)
+
+    def test_require_is_ok_with_unset_boolean(self):
+        self.settings.boolean(['foo'], 'foo help')
+        self.assertEqual(self.settings.require('foo'), None)
+
+    def test_require_is_ok_with_unset_bytesize(self):
+        self.settings.bytesize(['foo'], 'foo help')
+        self.assertEqual(self.settings.require('foo'), None)
+
+    def test_require_is_ok_with_unset_integer(self):
+        self.settings.integer(['foo'], 'foo help')
+        self.assertEqual(self.settings.require('foo'), None)
+
+    def test_exports_configparser_with_settings(self):
+        self.settings.integer(['foo'], 'foo help', default=1)
+        self.settings.string(['bar'], 'bar help', default='yo')
+        cp = self.settings.as_cp()
+        self.assertEqual(cp.get('config', 'foo'), '1')
+        self.assertEqual(cp.get('config', 'bar'), 'yo')
+
+    def test_exports_all_config_sections_via_as_cp(self):
+
+        def mock_open(filename, mode=None):
+            return StringIO.StringIO('''\
+[config]
+foo = yeehaa
+
+[other]
+bar = dodo
+''')
+
+        self.settings.string(['foo'], 'foo help', default='foo')
+        self.settings.config_files = ['whatever.conf']
+        self.settings.load_configs(open=mock_open)
+        cp = self.settings.as_cp()
+
+        self.assertEqual(sorted(cp.sections()), ['config', 'other'])
+        self.assertEqual(cp.get('config', 'foo'), 'yeehaa')
+        self.assertEqual(cp.options('other'), ['bar'])
+        self.assertEqual(cp.get('other', 'bar'), 'dodo')
+