command line commands fetched from erudi

1 files changed, 120 insertions, 0 deletions

diff --git a/clcommands.py b/clcommands.py
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+++ b/clcommands.py
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+# Copyright (c) 2004-2006 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) 2004-2006 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 = ''
+    
+    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 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 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  * %s.
+''' % '\n  * '.join(commands))
+    doc = doc.replace('%prog', basename(sys.argv[0]))
+    print 'usage:', doc
+    print 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)
+    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)