Split out the big chromite shell 'main.py' into lots of subfiles.

shell/subcmds/workon_cmd.py

+# Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Implementation of the 'workon' chromite command."""
+
+
+import chromite.lib.cros_build_lib as cros_lib
+from chromite.shell import subcmd
+
+
+class WorkonCmd(subcmd.WrappedChrootCmd):
+  """Run cros_workon."""
+
+  def __init__(self):
+    """WorkonCmd constructor."""
+    # Just call the WrappedChrootCmd superclass, which does most of the work.
+    # Note that host version uses "./", since it's in src/scripts and not in the
+    # path...
+    super(WorkonCmd, self).__init__(
+        ['cros_workon-%s'], ['./cros_workon', '--host'],
+        need_args=True
+    )
+
+  def Run(self, raw_argv, *args, **kwargs):
+    """Run the command.
+
+    We do just a slight optimization to help users with a common typo.
+
+    Args:
+      raw_argv: Command line arguments, including this command's name, but not
+          the chromite command name or chromite options.
+      args: The rest of the positional arguments.  See _DoWrappedChrootCommand.
+      kwargs: The keyword arguments.  See _DoWrappedChrootCommand.
+    """
+    # Slight optimization, just since I do this all the time...
+    if len(raw_argv) >= 2:
+      if raw_argv[1] in ('start', 'stop', 'list', 'list-all', 'iterate'):
+        cros_lib.Warning('OOPS, looks like you forgot a board name. Pick one.')
+        raw_argv = raw_argv[:1] + [''] + raw_argv[1:]
+
+    super(WorkonCmd, self).Run(raw_argv, *args, **kwargs)