Allow running plugins from the cli with calibre-debug easily

src/calibre/customize/__init__.py

@@ -293,6 +293,14 @@ class Plugin(object): # {{{
         if hasattr(it, '__exit__'):
             it.__exit__(*args)
 
+    def cli_main(self, args):
+        '''
+        This method is the main entry point for your plugins command line
+        interface. It is called when the user does: calibre-debug
+        '''
+        raise NotImplementedError('The %s plugin has no command line interface'
+                                  %self.name)
+
 # }}}
 
 class FileTypePlugin(Plugin): # {{{

src/calibre/debug.py

@@ -75,9 +75,12 @@ Everything after the -- is passed to the script.
             help=_('Cause a running calibre instance, if any, to be'
                 ' shutdown. Note that if there are running jobs, they '
                 'will be silently aborted, so use with care.'))
-
     parser.add_option('--test-build', help='Test binary modules in build',
             action='store_true', default=False)
+    parser.add_option('-r', '--run-plugin', help=_(
+        'Run a plugin that provides a command line interface. For example:\n'
+        'calibre-debug -r "Add Books" -- file1 --option1\n'
+        'Everything after the -- will be passed to the plugin as arguments.'))
 
     return parser
 
@@ -262,6 +265,13 @@ def main(args=sys.argv):
         main(['subset-font']+[opts.subset_font]+args[1:])
     elif opts.exec_file:
         run_script(opts.exec_file, args[1:])
+    elif opts.run_plugin:
+        from calibre.customize.ui import find_plugin
+        plugin = find_plugin(opts.run_plugin)
+        if plugin is None:
+            prints(_('No plugin named %s found')%opts.run_plugin)
+            raise SystemExit(1)
+        plugin.cli_main([plugin.name] + args[1:])
     elif len(args) >= 2 and args[1].rpartition('.')[-1] in {'py', 'recipe'}:
         run_script(args[1], args[2:])
     else: