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# Copyright (c) 2004-2007 LOGILAB S.A. (Paris, FRANCE).
# http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# 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.,
# 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
"""provides helper functions to handle a command line tool providing more than
one command
e.g called as "tool command [options] args..." where <options> and <args> are
command'specific
"""
import sys
from os.path import basename
from logilab.common.configuration import Configuration
DEFAULT_COPYRIGHT = '''\
Copyright (c) 2004-2007 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
http://www.logilab.fr/ -- mailto:contact@logilab.fr'''
class BadCommandUsage(Exception):
"""Raised when an unknown command is used or when a command is not
correctly used
"""
class Command(Configuration):
"""base class for command line commands"""
arguments = ''
name = ''
# max/min args, None meaning unspecified
min_args = None
max_args = None
def __init__(self, __doc__=None, version=None):
if __doc__:
usage = __doc__ % (self.name, self.arguments,
self.__doc__.replace(' ', ''))
else:
usage = self.__doc__.replace(' ', '')
Configuration.__init__(self, usage=usage, version=version)
def check_args(self, args):
"""check command's arguments are provided"""
if self.min_args is not None and len(args) < self.min_args:
raise BadCommandUsage('missing argument')
if self.max_args is not None and len(args) > self.max_args:
raise BadCommandUsage('too many arguments')
def run(self, args):
"""run the command with its specific arguments"""
raise NotImplementedError()
def pop_arg(args_list, expected_size_after=0, msg="Missing argument"):
"""helper function to get and check command line arguments"""
try:
value = args_list.pop(0)
except IndexError:
raise BadCommandUsage(msg)
if expected_size_after is not None and len(args_list) > expected_size_after:
raise BadCommandUsage('Too much arguments')
return value
_COMMANDS = {}
def register_commands(commands):
"""register existing commands"""
for command_klass in commands:
_COMMANDS[command_klass.name] = command_klass
def main_usage(status=0, __doc__=None, copyright=DEFAULT_COPYRIGHT):
"""display usage for the main program (ie when no command supplied)
and exit
"""
commands = _COMMANDS.keys()
commands.sort()
doc = __doc__ % ('<command>', '<command arguments>',
'''\
Type "%prog <command> --help" for more information about a specific
command. Available commands are :\n''')
doc = doc.replace('%prog', basename(sys.argv[0]))
print 'usage:', doc
max_len = max([len(cmd) for cmd in commands]) # list comprehension for py 2.3 support
padding = ' '*max_len
for command in commands:
cmd = _COMMANDS[command]
title = cmd.__doc__.split('.')[0]
print ' ', (command+padding)[:max_len], title
print '\n', copyright
sys.exit(status)
def cmd_run(cmdname, *args):
try:
command = _COMMANDS[cmdname](__doc__='%%prog %s %s\n\n%s')
except KeyError:
raise BadCommandUsage('no %s command' % cmdname)
args = command.load_command_line_configuration(args)
command.check_args(args)
try:
command.run(args)
except KeyboardInterrupt:
print 'interrupted'
except BadCommandUsage, err:
print 'ERROR: ', err
print command.help()
def main_run(args, doc):
"""command line tool"""
try:
arg = args.pop(0)
except IndexError:
main_usage(status=1, __doc__=doc)
if arg in ('-h', '--help'):
main_usage(__doc__=doc)
try:
cmd_run(arg, *args)
except BadCommandUsage, err:
print 'ERROR: ', err
main_usage(1, doc)
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