Added safe /execute and /show commands. May be moved to plugins later

src/command_system/implementation/execute.py

+# Copyright (c) 2010, Alexander Cherniuk (ts33kr@gmail.com)
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# * Redistributions of source code must retain the above copyright
+#   notice, this list of conditions and the following disclaimer.
+#
+# * Redistributions in binary form must reproduce the above copyright
+#   notice, this list of conditions and the following disclaimer in the
+#   documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""
+Provides facilities to safely execute expressions inside a shell process
+and capture the resulting output, in an asynchronous fashion, avoiding
+deadlocks. If the process execution time reaches the threshold - it is
+forced to terminate. Consists of a tiny framework and a couple of
+commands as a frontend.
+"""
+
+from subprocess import Popen, PIPE
+from os.path import expanduser
+
+from glib import timeout_add
+
+from ..framework import CommandContainer, command, doc
+from hosts import *
+
+class Execute(CommandContainer):
+    HOSTS = ChatCommands, PrivateChatCommands, GroupChatCommands
+
+    DIRECTORY = "~"
+
+    POLL_TIME = 100
+    POLL_COUNT = 5
+
+    @command("exec", raw=True)
+    @doc(_("Execute expression inside a shell, show output"))
+    def execute(self, expression):
+        Execute.spawn(self, expression)
+
+    @classmethod
+    def spawn(cls, processor, expression):
+        pipes = dict(stdout=PIPE, stderr=PIPE)
+        directory = expanduser(cls.DIRECTORY)
+        popen = Popen(expression, shell=True, cwd=directory, **pipes)
+        cls.monitor(processor, popen)
+
+    @classmethod
+    def monitor(cls, processor, popen):
+        poller = cls.poller(processor, popen)
+        timeout_add(cls.POLL_TIME, poller.next)
+
+    @classmethod
+    def poller(cls, processor, popen):
+        for x in xrange(cls.POLL_COUNT):
+            yield cls.brush(processor, popen)
+        cls.overdue(processor, popen)
+        yield False
+
+    @classmethod
+    def brush(cls, processor, popen):
+        if popen.poll() is not None:
+            cls.terminated(processor, popen)
+            return False
+        return True
+
+    @classmethod
+    def terminated(cls, processor, popen):
+        stdout, stderr = cls.fetch(popen)
+        if stdout:
+            processor.echo(stdout)
+        elif stderr:
+            processor.echo(stderr)
+
+    @classmethod
+    def overdue(cls, processor, popen):
+        popen.terminate()
+
+    @classmethod
+    def fetch(cls, popen):
+        data = popen.communicate()
+        return map(cls.clean, data)
+
+    @staticmethod
+    def clean(text):
+        strip = chr(10) + chr(32)
+        return text.strip(strip)
+
+class Show(Execute):
+
+    @command("sh", raw=True)
+    @doc(_("Execute expression inside a shell, send output"))
+    def show(self, expression):
+        Show.spawn(self, expression)
+
+    @classmethod
+    def terminated(cls, processor, popen):
+        stdout, stderr = cls.fetch(popen)
+        if stdout:
+            processor.send(stdout)
+        elif stderr:
+            processor.send(stderr)
\ No newline at end of file

src/command_system/implementation/standard.py

@@ -30,7 +30,8 @@ from ..errors import CommandError
 from ..framework import CommandContainer, command, doc
 from ..mapping import generate_usage
 
-from hosts import ChatCommands, PrivateChatCommands, GroupChatCommands
+from hosts import *
+import execute
 
 # This holds constants fron the logger, which we'll be using in some of our
 # commands.
@@ -42,7 +43,7 @@ class StandardCommonCommands(CommandContainer):
     to all - chat, private chat, group chat.
     """
 
-    HOSTS = (ChatCommands, PrivateChatCommands, GroupChatCommands)
+    HOSTS = ChatCommands, PrivateChatCommands, GroupChatCommands
 
     @command
     @doc(_("Clear the text window"))
@@ -163,7 +164,7 @@ class StandardCommonChatCommands(CommandContainer):
     to a chat and a private chat only.
     """
 
-    HOSTS = (ChatCommands, PrivateChatCommands)
+    HOSTS = ChatCommands, PrivateChatCommands
 
     @command
     @doc(_("Toggle the GPG encryption"))