Automatic Commit By liuyuqi

README.md

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+[![PyPI](https://img.shields.io/badge/Python-All-blue.svg)]()
+[![Build](https://img.shields.io/badge/Supported_OS-All-orange.svg)]()
+
+# FileMonitor
+代码审计辅助工具（文件监控）
+
+# 更新：
+
+2019-05-11：
+  修复bug 新增无需第三方模块的版本以及php版本。
+
+# 使用：
+
+### 环境：
+MacOS 10.14  Python2/3环境运行通过
+
+windows 7 Python2.7环境运行通过
+
+如有问题或修改意见 请点击===>[问题反馈](https://github.com/TheKingOfDuck/FileMonitor/issues)
+
+### 依赖：
+
+
+> [watchdog](https://pypi.org/project/watchdog/)
+
+可执行以下命令尝试安装
+
+```
+pip install watchdog
+easy_install watchdog
+```
+
+### 运行：
+
+```
+git clone https://github.com/TheKingOfDuck/FileMonitor.git
+cd FileMonitor
+python fileMonitor.py
+```
+
+MacOS可pip直接安装：
+
+```
+sudo python2 -m pip install filemon
+
+filemon
+```
+
+无需依赖版：
+
+```
+python main.py
+```
+(路径可为相对路径)
+
+php版本：
+
+```
+php fileMonitor.php --dir ./
+```
+
+
+# 功能
+
+* 排除不需要监控的文件目录(如测试基于thinkphp开发的CMS时可排除runtime目录)
+
+* 显示/不显示目录变化(程序运行过程中读写变化很快 根据自身需求决定是否需要显示目录变化)
+
+![screenshot](https://github.com/TheKingOfDuck/FileMonitor/blob/master/screenshot.png)
+
+### 应用场景：
+
+* https://xz.aliyun.com/t/3767
+* https://xz.aliyun.com/t/3788
+        
+
+
+## 注意：所输入的路径均为绝对路径。
+
+

fileMonitor.php

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+<?php
+/*
+-------------------------------------------------
+   File Name：     fileMonitor
+   Description :
+   Author :       CoolCat
+   date：          2019/1/3
+-------------------------------------------------
+   Change Activity:
+                   2019/1/3:
+-------------------------------------------------
+*/
+class FileMonitor
+{
+	private $dir;
+	private $i=0;
+	private $files = [];
+	private $filesize = [];
+	public function __construct($argv)
+	{
+		$this->dir = $this->getparam($argv);
+		$this->getfiles($this->dir);
+		print "[+] total:".count($this->files[$this->i])."\n\r";
+		$this->i++;
+		while(true)
+		{
+			$this->getfiles($this->dir);
+			if(isset($this->files[$this->i-1]) && ((count($this->files[$this->i])>count($this->files[$this->i-1]))))
+			{
+				print "[+] total:".count($this->files[$this->i])."\n\r";
+				print "[*] addfile: ".implode('|',array_diff($this->files[$this->i],$this->files[$this->i-1]))."\n\r";
+			}
+			if(isset($this->files[$this->i-1]) && ((count($this->files[$this->i])<count($this->files[$this->i-1]))))
+			{
+				print "[+] total:".count($this->files[$this->i])."\n\r";
+				print "[*] deletefile: ".implode('|',array_diff($this->files[$this->i-1],$this->files[$this->i]))."\n\r";
+			}
+			if(isset($this->filesize[$this->i-1]))
+			{
+				array_map(function($v,$val,$key){
+					if($v != $val)
+					{
+						print "[*] updatefile:{$key}\n\r";
+					}
+				},$this->filesize[$this->i-1],$this->filesize[$this->i],array_keys($this->filesize[$this->i]));
+			}
+			$this->i++;
+			if($this->i>=30)
+			{
+				$this->files = [];
+				$this->filesize = [];
+				$this->i = 0;
+			}
+		}
+	}
+
+	private function getparam($argv)
+	{
+		foreach($argv as $key=>$val)
+		{
+			if($val == "--dir")
+			{
+				return is_dir($argv[$key+1])?$argv[$key+1]:exit("[-] directory does not exist!");
+			}
+		}
+	}
+
+	private function getfiles($dir)
+	{
+		if(is_dir($dir))
+		{
+			$d = scandir($dir);
+			foreach($d as $v)
+			{
+				if($v != '.' && $v != '..')
+				{
+					if(is_dir("{$dir}/{$v}"))
+					{
+						$this->getfiles("{$dir}/{$v}");	
+					}
+					else
+					{
+						$this->files[$this->i][] = "{$dir}/{$v}";
+						$this->filesize[$this->i]["{$dir}/{$v}"] = filesize("{$dir}/{$v}");
+					}
+				}
+			}
+		}
+		else
+		{
+			$this->files[$this->i][] = $dir;
+			$this->filesize[$this->i][$dir] = filesize($dir);
+		}
+	}
+}
+print " 
+    _____________
+   < FileMonitor >
+    -------------
+      /\_)o<
+     |       | 
+     | O . O |
+      \_____/
+    By CoolCat
+";
+new FileMonitor($argv);
+?>

fileMonitor.py

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+# -*- coding: utf-8 -*-
+"""
+-------------------------------------------------
+   File Name：     fileMonitor
+   Description :
+   Author :       CoolCat
+   date：          2019/1/3
+-------------------------------------------------
+   Change Activity:
+                   2019/1/3:
+-------------------------------------------------
+"""
+__author__ = 'CoolCat'
+
+from watchdog.observers import Observer
+from watchdog.events import *
+import time
+
+global doWithout
+global showDir
+
+
+class FileEventHandler(FileSystemEventHandler):
+
+
+    def __init__(self):
+        FileSystemEventHandler.__init__(self)
+
+
+    def on_moved(self, event):
+
+        ###  文件移动显示青色
+        if doWithout in event.src_path:
+            pass
+        elif event.is_directory and showDir == "y":
+            print(time.strftime('[%H:%M:%S]:') + "\033[0;36m%s\033[0m" % "directory moved from {0} to {1}".format(event.src_path,event.dest_path))
+            pass
+        elif event.is_directory == False:
+            print(time.strftime('[%H:%M:%S]:') + "\033[0;36m%s\033[0m" % "file moved from {0} to {1}".format(event.src_path,event.dest_path))
+
+    def on_created(self, event):
+
+        ###  文件创建显示绿色
+
+        if doWithout in event.src_path:
+            pass
+        elif event.is_directory and showDir == "y":
+            print(time.strftime('[%H:%M:%S]:') + "\033[5;32m%s\033[0m" % "directory created:{0}".format(event.src_path))
+            pass
+        elif event.is_directory == False:
+            print(time.strftime('[%H:%M:%S]:') + "\033[5;32m%s\033[0m" % "file created:{0}".format(event.src_path))
+
+    def on_deleted(self, event):
+
+        ###  文件删除显示红色
+        if doWithout in event.src_path:
+            pass
+        elif event.is_directory and showDir == "y":
+            print(time.strftime('[%H:%M:%S]:') + "\033[0;31m%s\033[0m" % "directory deleted:{0}".format(event.src_path))
+            pass
+        elif event.is_directory == False:
+            print(time.strftime('[%H:%M:%S]:') + "\033[0;31m%s\033[0m" % "file deleted:{0}".format(event.src_path))
+
+    def on_modified(self, event):
+
+        ###  文件修改显示蓝色
+        if doWithout in event.src_path:
+            pass
+        elif event.is_directory and showDir == "y":
+            print(time.strftime('[%H:%M:%S]:') + "\033[0;34m%s\033[0m" % "directory modified:{0}".format(event.src_path))
+            pass
+        elif event.is_directory == False:
+            print(time.strftime('[%H:%M:%S]:') + "\033[0;34m%s\033[0m" % "file modified:{0}".format(event.src_path))
+
+
+def help():
+    print(""" 
+    _____________
+   < FileMonitor >
+    -------------
+      /\_)o<
+     |       | 
+     | O . O |
+      \_____/
+    By CoolCat
+      """)
+
+if __name__ == "__main__":
+    help()
+
+    import sys
+    if sys.version_info.major == 2:
+        try:
+            monitorDir = raw_input(time.strftime('[%H:%M:%S]:') + "Please enter a directory:")
+            doWithout = raw_input(time.strftime('[%H:%M:%S]:') + "Unnecessary directory:")
+            showDir = raw_input(time.strftime('[%H:%M:%S]:') + "Display directory changes(y or n):")
+        except:
+            pass
+    else:
+        monitorDir = input(time.strftime('[%H:%M:%S]:') + "Please enter a directory:")
+        doWithout = input(time.strftime('[%H:%M:%S]:') + "Unnecessary directory:")
+        showDir = input(time.strftime('[%H:%M:%S]:') + "Display directory changes(y or n):")
+
+    print(time.strftime('[%H:%M:%S]:') + "\033[0;31m%s\033[0m" % "FileMonitor is running...")
+
+    # # monitorDir = "/Users/CoolCat/php"
+    # print(type(monitorDir))
+
+
+    observer = Observer()
+    event_handler = FileEventHandler()
+    observer.schedule(event_handler,monitorDir,True)
+    observer.start()
+    try:
+        while True:
+            time.sleep(1)
+    except KeyboardInterrupt:
+        observer.stop()
+    observer.join()
+
+

main.py

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+# -*- coding: utf-8 -*-
+"""
+-------------------------------------------------
+   File Name：     mian
+   Description :
+   Author :       CoolCat
+   date：          2019/5/11
+-------------------------------------------------
+   Change Activity:
+                   2019/5/11:
+-------------------------------------------------
+"""
+__author__ = 'CoolCat'
+
+import os
+import hashlib
+import time
+
+
+def monitor(dir):
+    fileDirs = []
+    for root, dirs, files in os.walk(dir, topdown=False):
+        for name in files:
+            # print(os.path.join(root, name))
+            fileDirs.append(os.path.join(root, name))
+
+    return fileDirs
+        # for name in dirs:
+        #     print(os.path.join(root, name))
+
+
+
+def calcMD5(filepath):
+    try:
+        with open(filepath, 'rb') as f:
+            md5obj = hashlib.md5()
+            md5obj.update(f.read())
+            hash = md5obj.hexdigest()
+            # print(hash)
+            return "修改了" + filepath + " Hash为：" + hash
+    except:
+        pass
+
+def help():
+    print(""" 
+    _____________
+   < FileMonitor >
+    -------------
+      /\_)o<
+     |       | 
+     | O . O |
+      \_____/
+    By CoolCat
+      """)
+
+def getDir():
+    try:
+        dir = str(raw_input(time.strftime('[%H:%M:%S]:') + "Please enter a directory:"))
+    except:
+        dir = str(input(time.strftime('[%H:%M:%S]:') + "Please enter a directory:"))
+        pass
+    return dir
+
+if __name__ == '__main__':
+
+    help()
+
+    try:
+        dir = str(raw_input(time.strftime('[%H:%M:%S]:') + "Please enter a directory:"))
+    except:
+        dir = str(input(time.strftime('[%H:%M:%S]:') + "Please enter a directory:"))
+        pass
+
+
+
+
+
+    # dir = "../Aliyun/"
+
+    print(time.strftime('[%H:%M:%S]:') + "FileMonitor is running...")
+
+    # print(dir)
+
+    a = monitor(dir)
+
+    while True:
+        #print(len(a))
+        b = monitor(dir)
+        #print(len(b))
+        if len(a) > len(b):
+            c = list(set(a).difference(set(b)))
+            try:
+                # print(len(a))
+                # print(len(b))
+                # print(len(c))
+                print(time.strftime('[%H:%M:%S]:') + "删除了" + str(c[-1]))
+                # a = b
+            except:
+                pass
+
+        elif len(b) > len(a):
+            c = list(set(b).difference(set(a)))
+            try:
+                print(time.strftime('[%H:%M:%S]:') + "新建了" + str(c[-1]))
+                # a = b
+            except:
+                pass
+
+        elif len(a) == len(b):
+            # print(len(a))
+            # print(len(b))
+            # print(len(c))
+            aList = []
+            for pathName in a:
+                hash = calcMD5(pathName)
+                aList.append(hash)
+
+            #print(aList)
+
+            bList = []
+            for pathName in b:
+                hash = calcMD5(pathName)
+                bList.append(hash)
+            #print(bList)
+
+            cList = list(set(aList).difference(set(bList)))
+            if len(cList) != 0:
+                try:
+                    # print(len(aList))
+                    # print(len(bList))
+                    # print(len(cList))
+                    print(time.strftime('[%H:%M:%S]:') + cList[-1])
+                except:
+                    pass
+                # a = b
+            else:
+                pass
+            a = b
+        else:
+            pass
+        a = b
+        #break
+
+

watchdog/__init__.py

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+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.

watchdog/events.py

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+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+:module: watchdog.events
+:synopsis: File system events and event handlers.
+:author: yesudeep@google.com (Yesudeep Mangalapilly)
+
+Event Classes
+-------------
+.. autoclass:: FileSystemEvent
+   :members:
+   :show-inheritance:
+   :inherited-members:
+
+.. autoclass:: FileSystemMovedEvent
+   :members:
+   :show-inheritance:
+
+.. autoclass:: FileMovedEvent
+   :members:
+   :show-inheritance:
+
+.. autoclass:: DirMovedEvent
+   :members:
+   :show-inheritance:
+
+.. autoclass:: FileModifiedEvent
+   :members:
+   :show-inheritance:
+
+.. autoclass:: DirModifiedEvent
+   :members:
+   :show-inheritance:
+
+.. autoclass:: FileCreatedEvent
+   :members:
+   :show-inheritance:
+
+.. autoclass:: DirCreatedEvent
+   :members:
+   :show-inheritance:
+
+.. autoclass:: FileDeletedEvent
+   :members:
+   :show-inheritance:
+
+.. autoclass:: DirDeletedEvent
+   :members:
+   :show-inheritance:
+
+
+Event Handler Classes
+---------------------
+.. autoclass:: FileSystemEventHandler
+   :members:
+   :show-inheritance:
+
+.. autoclass:: PatternMatchingEventHandler
+   :members:
+   :show-inheritance:
+
+.. autoclass:: RegexMatchingEventHandler
+   :members:
+   :show-inheritance:
+
+.. autoclass:: LoggingEventHandler
+   :members:
+   :show-inheritance:
+
+"""
+
+import os.path
+import logging
+import re
+from pathtools.patterns import match_any_paths
+from watchdog.utils import has_attribute
+from watchdog.utils import unicode_paths
+
+
+EVENT_TYPE_MOVED = 'moved'
+EVENT_TYPE_DELETED = 'deleted'
+EVENT_TYPE_CREATED = 'created'
+EVENT_TYPE_MODIFIED = 'modified'
+
+
+class FileSystemEvent(object):
+    """
+    Immutable type that represents a file system event that is triggered
+    when a change occurs on the monitored file system.
+
+    All FileSystemEvent objects are required to be immutable and hence
+    can be used as keys in dictionaries or be added to sets.
+    """
+
+    event_type = None
+    """The type of the event as a string."""
+
+    is_directory = False
+    """True if event was emitted for a directory; False otherwise."""
+
+    is_synthetic = False
+    """
+    True if event was synthesized; False otherwise.
+
+    These are events that weren't actually broadcast by the OS, but
+    are presumed to have happened based on other, actual events.
+    """
+
+    def __init__(self, src_path):
+        self._src_path = src_path
+
+    @property
+    def src_path(self):
+        """Source path of the file system object that triggered this event."""
+        return self._src_path
+
+    def __str__(self):
+        return self.__repr__()
+
+    def __repr__(self):
+        return ("<%(class_name)s: event_type=%(event_type)s, "
+                "src_path=%(src_path)r, "
+                "is_directory=%(is_directory)s>"
+                ) % (dict(
+                     class_name=self.__class__.__name__,
+                     event_type=self.event_type,
+                     src_path=self.src_path,
+                     is_directory=self.is_directory))
+
+    # Used for comparison of events.
+    @property
+    def key(self):
+        return (self.event_type, self.src_path, self.is_directory)
+
+    def __eq__(self, event):
+        return self.key == event.key
+
+    def __ne__(self, event):
+        return self.key != event.key
+
+    def __hash__(self):
+        return hash(self.key)
+
+
+class FileSystemMovedEvent(FileSystemEvent):
+    """
+    File system event representing any kind of file system movement.
+    """
+
+    event_type = EVENT_TYPE_MOVED
+
+    def __init__(self, src_path, dest_path):
+        super(FileSystemMovedEvent, self).__init__(src_path)
+        self._dest_path = dest_path
+
+    @property
+    def dest_path(self):
+        """The destination path of the move event."""
+        return self._dest_path
+
+    # Used for hashing this as an immutable object.
+    @property
+    def key(self):
+        return (self.event_type, self.src_path, self.dest_path, self.is_directory)
+
+    def __repr__(self):
+        return ("<%(class_name)s: src_path=%(src_path)r, "
+                "dest_path=%(dest_path)r, "
+                "is_directory=%(is_directory)s>"
+                ) % (dict(class_name=self.__class__.__name__,
+                          src_path=self.src_path,
+                          dest_path=self.dest_path,
+                          is_directory=self.is_directory))
+
+
+# File events.
+
+
+class FileDeletedEvent(FileSystemEvent):
+    """File system event representing file deletion on the file system."""
+
+    event_type = EVENT_TYPE_DELETED
+
+    def __init__(self, src_path):
+        super(FileDeletedEvent, self).__init__(src_path)
+
+    def __repr__(self):
+        return "<%(class_name)s: src_path=%(src_path)r>" %\
+               dict(class_name=self.__class__.__name__,
+                    src_path=self.src_path)
+
+
+class FileModifiedEvent(FileSystemEvent):
+    """File system event representing file modification on the file system."""
+
+    event_type = EVENT_TYPE_MODIFIED
+
+    def __init__(self, src_path):
+        super(FileModifiedEvent, self).__init__(src_path)
+
+    def __repr__(self):
+        return ("<%(class_name)s: src_path=%(src_path)r>"
+                ) % (dict(class_name=self.__class__.__name__,
+                          src_path=self.src_path))
+
+
+class FileCreatedEvent(FileSystemEvent):
+    """File system event representing file creation on the file system."""
+
+    event_type = EVENT_TYPE_CREATED
+
+    def __init__(self, src_path):
+        super(FileCreatedEvent, self).__init__(src_path)
+
+    def __repr__(self):
+        return ("<%(class_name)s: src_path=%(src_path)r>"
+                ) % (dict(class_name=self.__class__.__name__,
+                          src_path=self.src_path))
+
+
+class FileMovedEvent(FileSystemMovedEvent):
+    """File system event representing file movement on the file system."""
+
+    def __init__(self, src_path, dest_path):
+        super(FileMovedEvent, self).__init__(src_path, dest_path)
+
+    def __repr__(self):
+        return ("<%(class_name)s: src_path=%(src_path)r, "
+                "dest_path=%(dest_path)r>"
+                ) % (dict(class_name=self.__class__.__name__,
+                          src_path=self.src_path,
+                          dest_path=self.dest_path))
+
+
+# Directory events.
+
+
+class DirDeletedEvent(FileSystemEvent):
+    """File system event representing directory deletion on the file system."""
+
+    event_type = EVENT_TYPE_DELETED
+    is_directory = True
+
+    def __init__(self, src_path):
+        super(DirDeletedEvent, self).__init__(src_path)
+
+    def __repr__(self):
+        return ("<%(class_name)s: src_path=%(src_path)r>"
+                ) % (dict(class_name=self.__class__.__name__,
+                          src_path=self.src_path))
+
+
+class DirModifiedEvent(FileSystemEvent):
+    """
+    File system event representing directory modification on the file system.
+    """
+
+    event_type = EVENT_TYPE_MODIFIED
+    is_directory = True
+
+    def __init__(self, src_path):
+        super(DirModifiedEvent, self).__init__(src_path)
+
+    def __repr__(self):
+        return ("<%(class_name)s: src_path=%(src_path)r>"
+                ) % (dict(class_name=self.__class__.__name__,
+                          src_path=self.src_path))
+
+
+class DirCreatedEvent(FileSystemEvent):
+    """File system event representing directory creation on the file system."""
+
+    event_type = EVENT_TYPE_CREATED
+    is_directory = True
+
+    def __init__(self, src_path):
+        super(DirCreatedEvent, self).__init__(src_path)
+
+    def __repr__(self):
+        return ("<%(class_name)s: src_path=%(src_path)r>"
+                ) % (dict(class_name=self.__class__.__name__,
+                          src_path=self.src_path))
+
+
+class DirMovedEvent(FileSystemMovedEvent):
+    """File system event representing directory movement on the file system."""
+
+    is_directory = True
+
+    def __init__(self, src_path, dest_path):
+        super(DirMovedEvent, self).__init__(src_path, dest_path)
+
+    def __repr__(self):
+        return ("<%(class_name)s: src_path=%(src_path)r, "
+                "dest_path=%(dest_path)r>"
+                ) % (dict(class_name=self.__class__.__name__,
+                          src_path=self.src_path,
+                          dest_path=self.dest_path))
+
+
+class FileSystemEventHandler(object):
+    """
+    Base file system event handler that you can override methods from.
+    """
+
+    def dispatch(self, event):
+        """Dispatches events to the appropriate methods.
+
+        :param event:
+            The event object representing the file system event.
+        :type event:
+            :class:`FileSystemEvent`
+        """
+        self.on_any_event(event)
+        _method_map = {
+            EVENT_TYPE_MODIFIED: self.on_modified,
+            EVENT_TYPE_MOVED: self.on_moved,
+            EVENT_TYPE_CREATED: self.on_created,
+            EVENT_TYPE_DELETED: self.on_deleted,
+        }
+        event_type = event.event_type
+        _method_map[event_type](event)
+
+    def on_any_event(self, event):
+        """Catch-all event handler.
+
+        :param event:
+            The event object representing the file system event.
+        :type event:
+            :class:`FileSystemEvent`
+        """
+
+    def on_moved(self, event):
+        """Called when a file or a directory is moved or renamed.
+
+        :param event:
+            Event representing file/directory movement.
+        :type event:
+            :class:`DirMovedEvent` or :class:`FileMovedEvent`
+        """
+
+    def on_created(self, event):
+        """Called when a file or directory is created.
+
+        :param event:
+            Event representing file/directory creation.
+        :type event:
+            :class:`DirCreatedEvent` or :class:`FileCreatedEvent`
+        """
+
+    def on_deleted(self, event):
+        """Called when a file or directory is deleted.
+
+        :param event:
+            Event representing file/directory deletion.
+        :type event:
+            :class:`DirDeletedEvent` or :class:`FileDeletedEvent`
+        """
+
+    def on_modified(self, event):
+        """Called when a file or directory is modified.
+
+        :param event:
+            Event representing file/directory modification.
+        :type event:
+            :class:`DirModifiedEvent` or :class:`FileModifiedEvent`
+        """
+
+
+class PatternMatchingEventHandler(FileSystemEventHandler):
+    """
+    Matches given patterns with file paths associated with occurring events.
+    """
+
+    def __init__(self, patterns=None, ignore_patterns=None,
+                 ignore_directories=False, case_sensitive=False):
+        super(PatternMatchingEventHandler, self).__init__()
+
+        self._patterns = patterns
+        self._ignore_patterns = ignore_patterns
+        self._ignore_directories = ignore_directories
+        self._case_sensitive = case_sensitive
+
+    @property
+    def patterns(self):
+        """
+        (Read-only)
+        Patterns to allow matching event paths.
+        """
+        return self._patterns
+
+    @property
+    def ignore_patterns(self):
+        """
+        (Read-only)
+        Patterns to ignore matching event paths.
+        """
+        return self._ignore_patterns
+
+    @property
+    def ignore_directories(self):
+        """
+        (Read-only)
+        ``True`` if directories should be ignored; ``False`` otherwise.
+        """
+        return self._ignore_directories
+
+    @property
+    def case_sensitive(self):
+        """
+        (Read-only)
+        ``True`` if path names should be matched sensitive to case; ``False``
+        otherwise.
+        """
+        return self._case_sensitive
+
+    def dispatch(self, event):
+        """Dispatches events to the appropriate methods.
+
+        :param event:
+            The event object representing the file system event.
+        :type event:
+            :class:`FileSystemEvent`
+        """
+        if self.ignore_directories and event.is_directory:
+            return
+
+        paths = []
+        if has_attribute(event, 'dest_path'):
+            paths.append(unicode_paths.decode(event.dest_path))
+        if event.src_path:
+            paths.append(unicode_paths.decode(event.src_path))
+
+        if match_any_paths(paths,
+                           included_patterns=self.patterns,
+                           excluded_patterns=self.ignore_patterns,
+                           case_sensitive=self.case_sensitive):
+            self.on_any_event(event)
+            _method_map = {
+                EVENT_TYPE_MODIFIED: self.on_modified,
+                EVENT_TYPE_MOVED: self.on_moved,
+                EVENT_TYPE_CREATED: self.on_created,
+                EVENT_TYPE_DELETED: self.on_deleted,
+            }
+            event_type = event.event_type
+            _method_map[event_type](event)
+
+
+class RegexMatchingEventHandler(FileSystemEventHandler):
+    """
+    Matches given regexes with file paths associated with occurring events.
+    """
+
+    def __init__(self, regexes=[r".*"], ignore_regexes=[],
+                 ignore_directories=False, case_sensitive=False):
+        super(RegexMatchingEventHandler, self).__init__()
+
+        if case_sensitive:
+            self._regexes = [re.compile(r) for r in regexes]
+            self._ignore_regexes = [re.compile(r) for r in ignore_regexes]
+        else:
+            self._regexes = [re.compile(r, re.I) for r in regexes]
+            self._ignore_regexes = [re.compile(r, re.I) for r in ignore_regexes]
+        self._ignore_directories = ignore_directories
+        self._case_sensitive = case_sensitive
+
+    @property
+    def regexes(self):
+        """
+        (Read-only)
+        Regexes to allow matching event paths.
+        """
+        return self._regexes
+
+    @property
+    def ignore_regexes(self):
+        """
+        (Read-only)
+        Regexes to ignore matching event paths.
+        """
+        return self._ignore_regexes
+
+    @property
+    def ignore_directories(self):
+        """
+        (Read-only)
+        ``True`` if directories should be ignored; ``False`` otherwise.
+        """
+        return self._ignore_directories
+
+    @property
+    def case_sensitive(self):
+        """
+        (Read-only)
+        ``True`` if path names should be matched sensitive to case; ``False``
+        otherwise.
+        """
+        return self._case_sensitive
+
+    def dispatch(self, event):
+        """Dispatches events to the appropriate methods.
+
+        :param event:
+            The event object representing the file system event.
+        :type event:
+            :class:`FileSystemEvent`
+        """
+        if self.ignore_directories and event.is_directory:
+            return
+
+        paths = []
+        if has_attribute(event, 'dest_path'):
+            paths.append(unicode_paths.decode(event.dest_path))
+        if event.src_path:
+            paths.append(unicode_paths.decode(event.src_path))
+
+        if any(r.match(p) for r in self.ignore_regexes for p in paths):
+            return
+
+        if any(r.match(p) for r in self.regexes for p in paths):
+            self.on_any_event(event)
+            _method_map = {
+                EVENT_TYPE_MODIFIED: self.on_modified,
+                EVENT_TYPE_MOVED: self.on_moved,
+                EVENT_TYPE_CREATED: self.on_created,
+                EVENT_TYPE_DELETED: self.on_deleted,
+            }
+            event_type = event.event_type
+            _method_map[event_type](event)
+
+
+class LoggingEventHandler(FileSystemEventHandler):
+    """Logs all the events captured."""
+
+    def on_moved(self, event):
+        super(LoggingEventHandler, self).on_moved(event)
+
+        what = 'directory' if event.is_directory else 'file'
+        logging.info("Moved %s: from %s to %s", what, event.src_path,
+                     event.dest_path)
+
+    def on_created(self, event):
+        super(LoggingEventHandler, self).on_created(event)
+
+        what = 'directory' if event.is_directory else 'file'
+        logging.info("Created %s: %s", what, event.src_path)
+
+    def on_deleted(self, event):
+        super(LoggingEventHandler, self).on_deleted(event)
+
+        what = 'directory' if event.is_directory else 'file'
+        logging.info("Deleted %s: %s", what, event.src_path)
+
+    def on_modified(self, event):
+        super(LoggingEventHandler, self).on_modified(event)
+
+        what = 'directory' if event.is_directory else 'file'
+        logging.info("Modified %s: %s", what, event.src_path)
+
+
+class LoggingFileSystemEventHandler(LoggingEventHandler):
+    """
+    For backwards-compatibility. Please use :class:`LoggingEventHandler`
+    instead.
+    """
+
+
+def generate_sub_moved_events(src_dir_path, dest_dir_path):
+    """Generates an event list of :class:`DirMovedEvent` and
+    :class:`FileMovedEvent` objects for all the files and directories within
+    the given moved directory that were moved along with the directory.
+
+    :param src_dir_path:
+        The source path of the moved directory.
+    :param dest_dir_path:
+        The destination path of the moved directory.
+    :returns:
+        An iterable of file system events of type :class:`DirMovedEvent` and
+        :class:`FileMovedEvent`.
+    """
+    for root, directories, filenames in os.walk(dest_dir_path):
+        for directory in directories:
+            full_path = os.path.join(root, directory)
+            renamed_path = full_path.replace(dest_dir_path, src_dir_path) if src_dir_path else None
+            event = DirMovedEvent(renamed_path, full_path)
+            event.is_synthetic = True
+            yield event
+        for filename in filenames:
+            full_path = os.path.join(root, filename)
+            renamed_path = full_path.replace(dest_dir_path, src_dir_path) if src_dir_path else None
+            event = FileMovedEvent(renamed_path, full_path)
+            event.is_synthetic = True
+            yield event
+
+
+def generate_sub_created_events(src_dir_path):
+    """Generates an event list of :class:`DirCreatedEvent` and
+    :class:`FileCreatedEvent` objects for all the files and directories within
+    the given moved directory that were moved along with the directory.
+
+    :param src_dir_path:
+        The source path of the created directory.
+    :returns:
+        An iterable of file system events of type :class:`DirCreatedEvent` and
+        :class:`FileCreatedEvent`.
+    """
+    for root, directories, filenames in os.walk(src_dir_path):
+        for directory in directories:
+            event = DirCreatedEvent(os.path.join(root, directory))
+            event.is_synthetic = True
+            yield event
+        for filename in filenames:
+            event = FileCreatedEvent(os.path.join(root, filename))
+            event.is_synthetic = True
+            yield event

watchdog/observers/__init__.py

@@ -0,0 +1,93 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+:module: watchdog.observers
+:synopsis: Observer that picks a native implementation if available.
+:author: yesudeep@google.com (Yesudeep Mangalapilly)
+
+
+Classes
+=======
+.. autoclass:: Observer
+   :members:
+   :show-inheritance:
+   :inherited-members:
+
+Observer thread that schedules watching directories and dispatches
+calls to event handlers.
+
+You can also import platform specific classes directly and use it instead
+of :class:`Observer`.  Here is a list of implemented observer classes.:
+
+============== ================================ ==============================
+Class          Platforms                        Note
+============== ================================ ==============================
+|Inotify|      Linux 2.6.13+                    ``inotify(7)`` based observer
+|FSEvents|     Mac OS X                         FSEvents based observer
+|Kqueue|       Mac OS X and BSD with kqueue(2)  ``kqueue(2)`` based observer
+|WinApi|       MS Windows                       Windows API-based observer
+|Polling|      Any                              fallback implementation
+============== ================================ ==============================
+
+.. |Inotify|     replace:: :class:`.inotify.InotifyObserver`
+.. |FSEvents|    replace:: :class:`.fsevents.FSEventsObserver`
+.. |Kqueue|      replace:: :class:`.kqueue.KqueueObserver`
+.. |WinApi|      replace:: :class:`.read_directory_changes.WindowsApiObserver`
+.. |WinApiAsync| replace:: :class:`.read_directory_changes_async.WindowsApiAsyncObserver`
+.. |Polling|     replace:: :class:`.polling.PollingObserver`
+
+"""
+
+import warnings
+from watchdog.utils import platform
+from watchdog.utils import UnsupportedLibc
+
+if platform.is_linux():
+    try:
+        from .inotify import InotifyObserver as Observer
+    except UnsupportedLibc:
+        from .polling import PollingObserver as Observer
+
+elif platform.is_darwin():
+    try:
+        from .fsevents import FSEventsObserver as Observer
+    except Exception:
+        try:
+            from .kqueue import KqueueObserver as Observer
+            warnings.warn("Failed to import fsevents. Fall back to kqueue")
+        except Exception:
+            from .polling import PollingObserver as Observer
+            warnings.warn("Failed to import fsevents and kqueue. Fall back to polling.")
+
+elif platform.is_bsd():
+    from .kqueue import KqueueObserver as Observer
+
+elif platform.is_windows():
+    # TODO: find a reliable way of checking Windows version and import
+    # polling explicitly for Windows XP
+    try:
+        from .read_directory_changes import WindowsApiObserver as Observer
+    except Exception:
+        from .polling import PollingObserver as Observer
+        warnings.warn("Failed to import read_directory_changes. Fall back to polling.")
+
+else:
+    from .polling import PollingObserver as Observer
+
+__all__ = ["Observer"]

watchdog/observers/api.py

@@ -0,0 +1,370 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import with_statement
+import threading
+from watchdog.utils import BaseThread
+from watchdog.utils.compat import queue
+from watchdog.utils.bricks import SkipRepeatsQueue
+
+DEFAULT_EMITTER_TIMEOUT = 1    # in seconds.
+DEFAULT_OBSERVER_TIMEOUT = 1   # in seconds.
+
+
+# Collection classes
+class EventQueue(SkipRepeatsQueue):
+    """Thread-safe event queue based on a special queue that skips adding
+    the same event (:class:`FileSystemEvent`) multiple times consecutively.
+    Thus avoiding dispatching multiple event handling
+    calls when multiple identical events are produced quicker than an observer
+    can consume them.
+    """
+
+
+class ObservedWatch(object):
+    """An scheduled watch.
+
+    :param path:
+        Path string.
+    :param recursive:
+        ``True`` if watch is recursive; ``False`` otherwise.
+    """
+
+    def __init__(self, path, recursive):
+        self._path = path
+        self._is_recursive = recursive
+
+    @property
+    def path(self):
+        """The path that this watch monitors."""
+        return self._path
+
+    @property
+    def is_recursive(self):
+        """Determines whether subdirectories are watched for the path."""
+        return self._is_recursive
+
+    @property
+    def key(self):
+        return self.path, self.is_recursive
+
+    def __eq__(self, watch):
+        return self.key == watch.key
+
+    def __ne__(self, watch):
+        return self.key != watch.key
+
+    def __hash__(self):
+        return hash(self.key)
+
+    def __repr__(self):
+        return "<%s: path=%s, is_recursive=%s>" % (
+            type(self).__name__, self.path, self.is_recursive)
+
+
+# Observer classes
+class EventEmitter(BaseThread):
+    """
+    Producer thread base class subclassed by event emitters
+    that generate events and populate a queue with them.
+
+    :param event_queue:
+        The event queue to populate with generated events.
+    :type event_queue:
+        :class:`watchdog.events.EventQueue`
+    :param watch:
+        The watch to observe and produce events for.
+    :type watch:
+        :class:`ObservedWatch`
+    :param timeout:
+        Timeout (in seconds) between successive attempts at reading events.
+    :type timeout:
+        ``float``
+    """
+
+    def __init__(self, event_queue, watch, timeout=DEFAULT_EMITTER_TIMEOUT):
+        BaseThread.__init__(self)
+        self._event_queue = event_queue
+        self._watch = watch
+        self._timeout = timeout
+
+    @property
+    def timeout(self):
+        """
+        Blocking timeout for reading events.
+        """
+        return self._timeout
+
+    @property
+    def watch(self):
+        """
+        The watch associated with this emitter.
+        """
+        return self._watch
+
+    def queue_event(self, event):
+        """
+        Queues a single event.
+
+        :param event:
+            Event to be queued.
+        :type event:
+            An instance of :class:`watchdog.events.FileSystemEvent`
+            or a subclass.
+        """
+        self._event_queue.put((event, self.watch))
+
+    def queue_events(self, timeout):
+        """Override this method to populate the event queue with events
+        per interval period.
+
+        :param timeout:
+            Timeout (in seconds) between successive attempts at
+            reading events.
+        :type timeout:
+            ``float``
+        """
+
+    def run(self):
+        while self.should_keep_running():
+            self.queue_events(self.timeout)
+
+
+class EventDispatcher(BaseThread):
+    """
+    Consumer thread base class subclassed by event observer threads
+    that dispatch events from an event queue to appropriate event handlers.
+
+    :param timeout:
+        Event queue blocking timeout (in seconds).
+    :type timeout:
+        ``float``
+    """
+
+    def __init__(self, timeout=DEFAULT_OBSERVER_TIMEOUT):
+        BaseThread.__init__(self)
+        self._event_queue = EventQueue()
+        self._timeout = timeout
+
+    @property
+    def timeout(self):
+        """Event queue block timeout."""
+        return self._timeout
+
+    @property
+    def event_queue(self):
+        """The event queue which is populated with file system events
+        by emitters and from which events are dispatched by a dispatcher
+        thread."""
+        return self._event_queue
+
+    def dispatch_events(self, event_queue, timeout):
+        """Override this method to consume events from an event queue, blocking
+        on the queue for the specified timeout before raising :class:`queue.Empty`.
+
+        :param event_queue:
+            Event queue to populate with one set of events.
+        :type event_queue:
+            :class:`EventQueue`
+        :param timeout:
+            Interval period (in seconds) to wait before timing out on the
+            event queue.
+        :type timeout:
+            ``float``
+        :raises:
+            :class:`queue.Empty`
+        """
+
+    def run(self):
+        while self.should_keep_running():
+            try:
+                self.dispatch_events(self.event_queue, self.timeout)
+            except queue.Empty:
+                continue
+
+
+class BaseObserver(EventDispatcher):
+    """Base observer."""
+
+    def __init__(self, emitter_class, timeout=DEFAULT_OBSERVER_TIMEOUT):
+        EventDispatcher.__init__(self, timeout)
+        self._emitter_class = emitter_class
+        self._lock = threading.RLock()
+        self._watches = set()
+        self._handlers = dict()
+        self._emitters = set()
+        self._emitter_for_watch = dict()
+
+    def _add_emitter(self, emitter):
+        self._emitter_for_watch[emitter.watch] = emitter
+        self._emitters.add(emitter)
+
+    def _remove_emitter(self, emitter):
+        del self._emitter_for_watch[emitter.watch]
+        self._emitters.remove(emitter)
+        emitter.stop()
+        try:
+            emitter.join()
+        except RuntimeError:
+            pass
+
+    def _clear_emitters(self):
+        for emitter in self._emitters:
+            emitter.stop()
+        for emitter in self._emitters:
+            try:
+                emitter.join()
+            except RuntimeError:
+                pass
+        self._emitters.clear()
+        self._emitter_for_watch.clear()
+
+    def _add_handler_for_watch(self, event_handler, watch):
+        if watch not in self._handlers:
+            self._handlers[watch] = set()
+        self._handlers[watch].add(event_handler)
+
+    def _remove_handlers_for_watch(self, watch):
+        del self._handlers[watch]
+
+    @property
+    def emitters(self):
+        """Returns event emitter created by this observer."""
+        return self._emitters
+
+    def start(self):
+        for emitter in self._emitters.copy():
+            try:
+                emitter.start()
+            except Exception:
+                self._remove_emitter(emitter)
+                raise
+        super(BaseObserver, self).start()
+
+    def schedule(self, event_handler, path, recursive=False):
+        """
+        Schedules watching a path and calls appropriate methods specified
+        in the given event handler in response to file system events.
+
+        :param event_handler:
+            An event handler instance that has appropriate event handling
+            methods which will be called by the observer in response to
+            file system events.
+        :type event_handler:
+            :class:`watchdog.events.FileSystemEventHandler` or a subclass
+        :param path:
+            Directory path that will be monitored.
+        :type path:
+            ``str``
+        :param recursive:
+            ``True`` if events will be emitted for sub-directories
+            traversed recursively; ``False`` otherwise.
+        :type recursive:
+            ``bool``
+        :return:
+            An :class:`ObservedWatch` object instance representing
+            a watch.
+        """
+        with self._lock:
+            watch = ObservedWatch(path, recursive)
+            self._add_handler_for_watch(event_handler, watch)
+
+            # If we don't have an emitter for this watch already, create it.
+            if self._emitter_for_watch.get(watch) is None:
+                emitter = self._emitter_class(event_queue=self.event_queue,
+                                              watch=watch,
+                                              timeout=self.timeout)
+                self._add_emitter(emitter)
+                if self.is_alive():
+                    emitter.start()
+            self._watches.add(watch)
+        return watch
+
+    def add_handler_for_watch(self, event_handler, watch):
+        """Adds a handler for the given watch.
+
+        :param event_handler:
+            An event handler instance that has appropriate event handling
+            methods which will be called by the observer in response to
+            file system events.
+        :type event_handler:
+            :class:`watchdog.events.FileSystemEventHandler` or a subclass
+        :param watch:
+            The watch to add a handler for.
+        :type watch:
+            An instance of :class:`ObservedWatch` or a subclass of
+            :class:`ObservedWatch`
+        """
+        with self._lock:
+            self._add_handler_for_watch(event_handler, watch)
+
+    def remove_handler_for_watch(self, event_handler, watch):
+        """Removes a handler for the given watch.
+
+        :param event_handler:
+            An event handler instance that has appropriate event handling
+            methods which will be called by the observer in response to
+            file system events.
+        :type event_handler:
+            :class:`watchdog.events.FileSystemEventHandler` or a subclass
+        :param watch:
+            The watch to remove a handler for.
+        :type watch:
+            An instance of :class:`ObservedWatch` or a subclass of
+            :class:`ObservedWatch`
+        """
+        with self._lock:
+            self._handlers[watch].remove(event_handler)
+
+    def unschedule(self, watch):
+        """Unschedules a watch.
+
+        :param watch:
+            The watch to unschedule.
+        :type watch:
+            An instance of :class:`ObservedWatch` or a subclass of
+            :class:`ObservedWatch`
+        """
+        with self._lock:
+            emitter = self._emitter_for_watch[watch]
+            del self._handlers[watch]
+            self._remove_emitter(emitter)
+            self._watches.remove(watch)
+
+    def unschedule_all(self):
+        """Unschedules all watches and detaches all associated event
+        handlers."""
+        with self._lock:
+            self._handlers.clear()
+            self._clear_emitters()
+            self._watches.clear()
+
+    def on_thread_stop(self):
+        self.unschedule_all()
+
+    def dispatch_events(self, event_queue, timeout):
+        event, watch = event_queue.get(block=True, timeout=timeout)
+
+        with self._lock:
+            # To allow unschedule/stop and safe removal of event handlers
+            # within event handlers itself, check if the handler is still
+            # registered after every dispatch.
+            for handler in list(self._handlers.get(watch, [])):
+                if handler in self._handlers.get(watch, []):
+                    handler.dispatch(event)
+        event_queue.task_done()

watchdog/observers/fsevents.py

@@ -0,0 +1,174 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+:module: watchdog.observers.fsevents
+:synopsis: FSEvents based emitter implementation.
+:author: yesudeep@google.com (Yesudeep Mangalapilly)
+:platforms: Mac OS X
+"""
+
+from __future__ import with_statement
+
+import sys
+import threading
+import unicodedata
+import _watchdog_fsevents as _fsevents
+
+from watchdog.events import (
+    FileDeletedEvent,
+    FileModifiedEvent,
+    FileCreatedEvent,
+    FileMovedEvent,
+    DirDeletedEvent,
+    DirModifiedEvent,
+    DirCreatedEvent,
+    DirMovedEvent
+)
+
+from watchdog.utils.dirsnapshot import DirectorySnapshot
+from watchdog.observers.api import (
+    BaseObserver,
+    EventEmitter,
+    DEFAULT_EMITTER_TIMEOUT,
+    DEFAULT_OBSERVER_TIMEOUT
+)
+
+
+class FSEventsEmitter(EventEmitter):
+
+    """
+    Mac OS X FSEvents Emitter class.
+
+    :param event_queue:
+        The event queue to fill with events.
+    :param watch:
+        A watch object representing the directory to monitor.
+    :type watch:
+        :class:`watchdog.observers.api.ObservedWatch`
+    :param timeout:
+        Read events blocking timeout (in seconds).
+    :type timeout:
+        ``float``
+    """
+
+    def __init__(self, event_queue, watch, timeout=DEFAULT_EMITTER_TIMEOUT):
+        EventEmitter.__init__(self, event_queue, watch, timeout)
+        self._lock = threading.Lock()
+        self.snapshot = DirectorySnapshot(watch.path, watch.is_recursive)
+
+    def on_thread_stop(self):
+        if self.watch:
+            _fsevents.remove_watch(self.watch)
+            _fsevents.stop(self)
+            self._watch = None
+
+    def queue_events(self, timeout):
+        with self._lock:
+            if (not self.watch.is_recursive
+                    and self.watch.path not in self.pathnames):
+                return
+            new_snapshot = DirectorySnapshot(self.watch.path,
+                                             self.watch.is_recursive)
+            events = new_snapshot - self.snapshot
+            self.snapshot = new_snapshot
+
+            # Files.
+            for src_path in events.files_deleted:
+                self.queue_event(FileDeletedEvent(src_path))
+            for src_path in events.files_modified:
+                self.queue_event(FileModifiedEvent(src_path))
+            for src_path in events.files_created:
+                self.queue_event(FileCreatedEvent(src_path))
+            for src_path, dest_path in events.files_moved:
+                self.queue_event(FileMovedEvent(src_path, dest_path))
+
+            # Directories.
+            for src_path in events.dirs_deleted:
+                self.queue_event(DirDeletedEvent(src_path))
+            for src_path in events.dirs_modified:
+                self.queue_event(DirModifiedEvent(src_path))
+            for src_path in events.dirs_created:
+                self.queue_event(DirCreatedEvent(src_path))
+            for src_path, dest_path in events.dirs_moved:
+                self.queue_event(DirMovedEvent(src_path, dest_path))
+
+    def run(self):
+        try:
+            def callback(pathnames, flags, emitter=self):
+                emitter.queue_events(emitter.timeout)
+
+            # for pathname, flag in zip(pathnames, flags):
+            # if emitter.watch.is_recursive: # and pathname != emitter.watch.path:
+            #    new_sub_snapshot = DirectorySnapshot(pathname, True)
+            #    old_sub_snapshot = self.snapshot.copy(pathname)
+            #    diff = new_sub_snapshot - old_sub_snapshot
+            #    self.snapshot += new_subsnapshot
+            # else:
+            #    new_snapshot = DirectorySnapshot(emitter.watch.path, False)
+            #    diff = new_snapshot - emitter.snapshot
+            #    emitter.snapshot = new_snapshot
+
+            # INFO: FSEvents reports directory notifications recursively
+            # by default, so we do not need to add subdirectory paths.
+            # pathnames = set([self.watch.path])
+            # if self.watch.is_recursive:
+            #    for root, directory_names, _ in os.walk(self.watch.path):
+            #        for directory_name in directory_names:
+            #            full_path = absolute_path(
+            #                            os.path.join(root, directory_name))
+            #            pathnames.add(full_path)
+            self.pathnames = [self.watch.path]
+            _fsevents.add_watch(self,
+                                self.watch,
+                                callback,
+                                self.pathnames)
+            _fsevents.read_events(self)
+        except Exception:
+            pass
+
+
+class FSEventsObserver(BaseObserver):
+
+    def __init__(self, timeout=DEFAULT_OBSERVER_TIMEOUT):
+        BaseObserver.__init__(self, emitter_class=FSEventsEmitter,
+                              timeout=timeout)
+
+    def schedule(self, event_handler, path, recursive=False):
+        # Python 2/3 compat
+        try:
+            str_class = unicode
+        except NameError:
+            str_class = str
+
+        # Fix for issue #26: Trace/BPT error when given a unicode path
+        # string. https://github.com/gorakhargosh/watchdog/issues#issue/26
+        if isinstance(path, str_class):
+            # path = unicode(path, 'utf-8')
+            path = unicodedata.normalize('NFC', path)
+            # We only encode the path in Python 2 for backwards compatibility.
+            # On Python 3 we want the path to stay as unicode if possible for
+            # the sake of path matching not having to be rewritten to use the
+            # bytes API instead of strings. The _watchdog_fsevent.so code for
+            # Python 3 can handle both str and bytes paths, which is why we
+            # do not HAVE to encode it with Python 3. The Python 2 code in
+            # _watchdog_fsevents.so was not changed for the sake of backwards
+            # compatibility.
+            if sys.version_info < (3,):
+                path = path.encode('utf-8')
+        return BaseObserver.schedule(self, event_handler, path, recursive)

watchdog/observers/fsevents2.py

@@ -0,0 +1,246 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright 2014 Thomas Amland <thomas.amland@gmail.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+:module: watchdog.observers.fsevents2
+:synopsis: FSEvents based emitter implementation.
+:platforms: Mac OS X
+"""
+
+import os
+import logging
+import unicodedata
+from threading import Thread
+from watchdog.utils.compat import queue
+
+from watchdog.events import (
+    FileDeletedEvent,
+    FileModifiedEvent,
+    FileCreatedEvent,
+    FileMovedEvent,
+    DirDeletedEvent,
+    DirModifiedEvent,
+    DirCreatedEvent,
+    DirMovedEvent
+)
+from watchdog.observers.api import (
+    BaseObserver,
+    EventEmitter,
+    DEFAULT_EMITTER_TIMEOUT,
+    DEFAULT_OBSERVER_TIMEOUT,
+)
+
+# pyobjc
+import AppKit
+from FSEvents import (
+    FSEventStreamCreate,
+    CFRunLoopGetCurrent,
+    FSEventStreamScheduleWithRunLoop,
+    FSEventStreamStart,
+    CFRunLoopRun,
+    CFRunLoopStop,
+    FSEventStreamStop,
+    FSEventStreamInvalidate,
+    FSEventStreamRelease,
+)
+
+from FSEvents import (
+    kCFAllocatorDefault,
+    kCFRunLoopDefaultMode,
+    kFSEventStreamEventIdSinceNow,
+    kFSEventStreamCreateFlagNoDefer,
+    kFSEventStreamCreateFlagFileEvents,
+    kFSEventStreamEventFlagItemCreated,
+    kFSEventStreamEventFlagItemRemoved,
+    kFSEventStreamEventFlagItemInodeMetaMod,
+    kFSEventStreamEventFlagItemRenamed,
+    kFSEventStreamEventFlagItemModified,
+    kFSEventStreamEventFlagItemFinderInfoMod,
+    kFSEventStreamEventFlagItemChangeOwner,
+    kFSEventStreamEventFlagItemXattrMod,
+    kFSEventStreamEventFlagItemIsDir,
+    kFSEventStreamEventFlagItemIsSymlink,
+)
+
+logger = logging.getLogger(__name__)
+
+
+class FSEventsQueue(Thread):
+    """ Low level FSEvents client. """
+
+    def __init__(self, path):
+        Thread.__init__(self)
+        self._queue = queue.Queue()
+        self._run_loop = None
+
+        if isinstance(path, bytes):
+            path = path.decode('utf-8')
+        self._path = unicodedata.normalize('NFC', path)
+
+        context = None
+        latency = 1.0
+        self._stream_ref = FSEventStreamCreate(
+            kCFAllocatorDefault, self._callback, context, [self._path],
+            kFSEventStreamEventIdSinceNow, latency,
+            kFSEventStreamCreateFlagNoDefer | kFSEventStreamCreateFlagFileEvents)
+        if self._stream_ref is None:
+            raise IOError("FSEvents. Could not create stream.")
+
+    def run(self):
+        pool = AppKit.NSAutoreleasePool.alloc().init()
+        self._run_loop = CFRunLoopGetCurrent()
+        FSEventStreamScheduleWithRunLoop(
+            self._stream_ref, self._run_loop, kCFRunLoopDefaultMode)
+        if not FSEventStreamStart(self._stream_ref):
+            FSEventStreamInvalidate(self._stream_ref)
+            FSEventStreamRelease(self._stream_ref)
+            raise IOError("FSEvents. Could not start stream.")
+
+        CFRunLoopRun()
+        FSEventStreamStop(self._stream_ref)
+        FSEventStreamInvalidate(self._stream_ref)
+        FSEventStreamRelease(self._stream_ref)
+        del pool
+        # Make sure waiting thread is notified
+        self._queue.put(None)
+
+    def stop(self):
+        if self._run_loop is not None:
+            CFRunLoopStop(self._run_loop)
+
+    def _callback(self, streamRef, clientCallBackInfo, numEvents, eventPaths, eventFlags, eventIDs):
+        events = [NativeEvent(path, flags, _id) for path, flags, _id in
+                  zip(eventPaths, eventFlags, eventIDs)]
+        logger.debug("FSEvents callback. Got %d events:" % numEvents)
+        for e in events:
+            logger.debug(e)
+        self._queue.put(events)
+
+    def read_events(self):
+        """
+        Returns a list or one or more events, or None if there are no more
+        events to be read.
+        """
+        if not self.is_alive():
+            return None
+        return self._queue.get()
+
+
+class NativeEvent(object):
+    def __init__(self, path, flags, event_id):
+        self.path = path
+        self.flags = flags
+        self.event_id = event_id
+        self.is_created = bool(flags & kFSEventStreamEventFlagItemCreated)
+        self.is_removed = bool(flags & kFSEventStreamEventFlagItemRemoved)
+        self.is_renamed = bool(flags & kFSEventStreamEventFlagItemRenamed)
+        self.is_modified = bool(flags & kFSEventStreamEventFlagItemModified)
+        self.is_change_owner = bool(flags & kFSEventStreamEventFlagItemChangeOwner)
+        self.is_inode_meta_mod = bool(flags & kFSEventStreamEventFlagItemInodeMetaMod)
+        self.is_finder_info_mod = bool(flags & kFSEventStreamEventFlagItemFinderInfoMod)
+        self.is_xattr_mod = bool(flags & kFSEventStreamEventFlagItemXattrMod)
+        self.is_symlink = bool(flags & kFSEventStreamEventFlagItemIsSymlink)
+        self.is_directory = bool(flags & kFSEventStreamEventFlagItemIsDir)
+
+    @property
+    def _event_type(self):
+        if self.is_created:
+            return "Created"
+        if self.is_removed:
+            return "Removed"
+        if self.is_renamed:
+            return "Renamed"
+        if self.is_modified:
+            return "Modified"
+        if self.is_inode_meta_mod:
+            return "InodeMetaMod"
+        if self.is_xattr_mod:
+            return "XattrMod"
+        return "Unknown"
+
+    def __repr__(self):
+        s = "<%s: path=%s, type=%s, is_dir=%s, flags=%s, id=%s>"
+        return s % (type(self).__name__, repr(self.path), self._event_type,
+                    self.is_directory, hex(self.flags), self.event_id)
+
+
+class FSEventsEmitter(EventEmitter):
+    """
+    FSEvents based event emitter. Handles conversion of native events.
+    """
+
+    def __init__(self, event_queue, watch, timeout=DEFAULT_EMITTER_TIMEOUT):
+        EventEmitter.__init__(self, event_queue, watch, timeout)
+        self._fsevents = FSEventsQueue(watch.path)
+        self._fsevents.start()
+
+    def on_thread_stop(self):
+        self._fsevents.stop()
+
+    def queue_events(self, timeout):
+        events = self._fsevents.read_events()
+        if events is None:
+            return
+        i = 0
+        while i < len(events):
+            event = events[i]
+
+            # For some reason the create and remove flags are sometimes also
+            # set for rename and modify type events, so let those take
+            # precedence.
+            if event.is_renamed:
+                # Internal moves appears to always be consecutive in the same
+                # buffer and have IDs differ by exactly one (while others
+                # don't) making it possible to pair up the two events coming
+                # from a singe move operation. (None of this is documented!)
+                # Otherwise, guess whether file was moved in or out.
+                # TODO: handle id wrapping
+                if (i + 1 < len(events) and events[i + 1].is_renamed
+                        and events[i + 1].event_id == event.event_id + 1):
+                    cls = DirMovedEvent if event.is_directory else FileMovedEvent
+                    self.queue_event(cls(event.path, events[i + 1].path))
+                    self.queue_event(DirModifiedEvent(os.path.dirname(event.path)))
+                    self.queue_event(DirModifiedEvent(os.path.dirname(events[i + 1].path)))
+                    i += 1
+                elif os.path.exists(event.path):
+                    cls = DirCreatedEvent if event.is_directory else FileCreatedEvent
+                    self.queue_event(cls(event.path))
+                    self.queue_event(DirModifiedEvent(os.path.dirname(event.path)))
+                else:
+                    cls = DirDeletedEvent if event.is_directory else FileDeletedEvent
+                    self.queue_event(cls(event.path))
+                    self.queue_event(DirModifiedEvent(os.path.dirname(event.path)))
+                # TODO: generate events for tree
+
+            elif event.is_modified or event.is_inode_meta_mod or event.is_xattr_mod :
+                cls = DirModifiedEvent if event.is_directory else FileModifiedEvent
+                self.queue_event(cls(event.path))
+
+            elif event.is_created:
+                cls = DirCreatedEvent if event.is_directory else FileCreatedEvent
+                self.queue_event(cls(event.path))
+                self.queue_event(DirModifiedEvent(os.path.dirname(event.path)))
+
+            elif event.is_removed:
+                cls = DirDeletedEvent if event.is_directory else FileDeletedEvent
+                self.queue_event(cls(event.path))
+                self.queue_event(DirModifiedEvent(os.path.dirname(event.path)))
+            i += 1
+
+
+class FSEventsObserver2(BaseObserver):
+    def __init__(self, timeout=DEFAULT_OBSERVER_TIMEOUT):
+        BaseObserver.__init__(self, emitter_class=FSEventsEmitter, timeout=timeout)

watchdog/observers/inotify.py

@@ -0,0 +1,219 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+:module: watchdog.observers.inotify
+:synopsis: ``inotify(7)`` based emitter implementation.
+:author: Sebastien Martini <seb@dbzteam.org>
+:author: Luke McCarthy <luke@iogopro.co.uk>
+:author: yesudeep@google.com (Yesudeep Mangalapilly)
+:author: Tim Cuthbertson <tim+github@gfxmonk.net>
+:platforms: Linux 2.6.13+.
+
+.. ADMONITION:: About system requirements
+
+    Recommended minimum kernel version: 2.6.25.
+
+    Quote from the inotify(7) man page:
+
+        "Inotify was merged into the 2.6.13 Linux kernel. The required library
+        interfaces were added to glibc in version 2.4. (IN_DONT_FOLLOW,
+        IN_MASK_ADD, and IN_ONLYDIR were only added in version 2.5.)"
+
+    Therefore, you must ensure the system is running at least these versions
+    appropriate libraries and the kernel.
+
+.. ADMONITION:: About recursiveness, event order, and event coalescing
+
+    Quote from the inotify(7) man page:
+
+        If successive output inotify events produced on the inotify file
+        descriptor are identical (same wd, mask, cookie, and name) then they
+        are coalesced into a single event if the older event has not yet been
+        read (but see BUGS).
+
+        The events returned by reading from an inotify file descriptor form
+        an ordered queue. Thus, for example, it is guaranteed that when
+        renaming from one directory to another, events will be produced in
+        the correct order on the inotify file descriptor.
+
+        ...
+
+        Inotify monitoring of directories is not recursive: to monitor
+        subdirectories under a directory, additional watches must be created.
+
+    This emitter implementation therefore automatically adds watches for
+    sub-directories if running in recursive mode.
+
+Some extremely useful articles and documentation:
+
+.. _inotify FAQ: http://inotify.aiken.cz/?section=inotify&page=faq&lang=en
+.. _intro to inotify: http://www.linuxjournal.com/article/8478
+
+"""
+
+from __future__ import with_statement
+
+import os
+import threading
+from .inotify_buffer import InotifyBuffer
+
+from watchdog.observers.api import (
+    EventEmitter,
+    BaseObserver,
+    DEFAULT_EMITTER_TIMEOUT,
+    DEFAULT_OBSERVER_TIMEOUT
+)
+
+from watchdog.events import (
+    DirDeletedEvent,
+    DirModifiedEvent,
+    DirMovedEvent,
+    DirCreatedEvent,
+    FileDeletedEvent,
+    FileModifiedEvent,
+    FileMovedEvent,
+    FileCreatedEvent,
+    generate_sub_moved_events,
+    generate_sub_created_events,
+)
+from watchdog.utils import unicode_paths
+
+
+class InotifyEmitter(EventEmitter):
+    """
+    inotify(7)-based event emitter.
+
+    :param event_queue:
+        The event queue to fill with events.
+    :param watch:
+        A watch object representing the directory to monitor.
+    :type watch:
+        :class:`watchdog.observers.api.ObservedWatch`
+    :param timeout:
+        Read events blocking timeout (in seconds).
+    :type timeout:
+        ``float``
+    """
+
+    def __init__(self, event_queue, watch, timeout=DEFAULT_EMITTER_TIMEOUT):
+        EventEmitter.__init__(self, event_queue, watch, timeout)
+        self._lock = threading.Lock()
+        self._inotify = None
+
+    def on_thread_start(self):
+        path = unicode_paths.encode(self.watch.path)
+        self._inotify = InotifyBuffer(path, self.watch.is_recursive)
+
+    def on_thread_stop(self):
+        if self._inotify:
+            self._inotify.close()
+
+    def queue_events(self, timeout, full_events=False):
+        # If "full_events" is true, then the method will report unmatched move events as seperate events
+        # This behavior is by default only called by a InotifyFullEmitter
+        with self._lock:
+            event = self._inotify.read_event()
+            if event is None:
+                return
+            if isinstance(event, tuple):
+                move_from, move_to = event
+                src_path = self._decode_path(move_from.src_path)
+                dest_path = self._decode_path(move_to.src_path)
+                cls = DirMovedEvent if move_from.is_directory else FileMovedEvent
+                self.queue_event(cls(src_path, dest_path))
+                self.queue_event(DirModifiedEvent(os.path.dirname(src_path)))
+                self.queue_event(DirModifiedEvent(os.path.dirname(dest_path)))
+                if move_from.is_directory and self.watch.is_recursive:
+                    for sub_event in generate_sub_moved_events(src_path, dest_path):
+                        self.queue_event(sub_event)
+                return
+
+            src_path = self._decode_path(event.src_path)
+            if event.is_moved_to:
+                if full_events:
+                    cls = DirMovedEvent if event.is_directory else FileMovedEvent
+                    self.queue_event(cls(None, src_path))
+                else:
+                    cls = DirCreatedEvent if event.is_directory else FileCreatedEvent
+                    self.queue_event(cls(src_path))
+                self.queue_event(DirModifiedEvent(os.path.dirname(src_path)))
+                if event.is_directory and self.watch.is_recursive:
+                    for sub_event in generate_sub_created_events(src_path):
+                        self.queue_event(sub_event)
+            elif event.is_attrib:
+                cls = DirModifiedEvent if event.is_directory else FileModifiedEvent
+                self.queue_event(cls(src_path))
+            elif event.is_modify:
+                cls = DirModifiedEvent if event.is_directory else FileModifiedEvent
+                self.queue_event(cls(src_path))
+            elif event.is_delete or (event.is_moved_from and not full_events):
+                cls = DirDeletedEvent if event.is_directory else FileDeletedEvent
+                self.queue_event(cls(src_path))
+                self.queue_event(DirModifiedEvent(os.path.dirname(src_path)))
+            elif event.is_moved_from and full_events:
+                cls = DirMovedEvent if event.is_directory else FileMovedEvent
+                self.queue_event(cls(src_path, None))
+                self.queue_event(DirModifiedEvent(os.path.dirname(src_path)))
+            elif event.is_create:
+                cls = DirCreatedEvent if event.is_directory else FileCreatedEvent
+                self.queue_event(cls(src_path))
+                self.queue_event(DirModifiedEvent(os.path.dirname(src_path)))
+
+    def _decode_path(self, path):
+        """ Decode path only if unicode string was passed to this emitter. """
+        if isinstance(self.watch.path, bytes):
+            return path
+        return unicode_paths.decode(path)
+
+
+class InotifyFullEmitter(InotifyEmitter):
+    """
+    inotify(7)-based event emitter. By default this class produces move events even if they are not matched
+    Such move events will have a ``None`` value for the unmatched part.
+
+    :param event_queue:
+        The event queue to fill with events.
+    :param watch:
+        A watch object representing the directory to monitor.
+    :type watch:
+        :class:`watchdog.observers.api.ObservedWatch`
+    :param timeout:
+        Read events blocking timeout (in seconds).
+    :type timeout:
+        ``float``
+    """
+    def __init__(self, event_queue, watch, timeout=DEFAULT_EMITTER_TIMEOUT):
+        InotifyEmitter.__init__(self, event_queue, watch, timeout)
+
+    def queue_events(self, timeout, events=True):
+        InotifyEmitter.queue_events(self, timeout, full_events=events)
+
+
+class InotifyObserver(BaseObserver):
+    """
+    Observer thread that schedules watching directories and dispatches
+    calls to event handlers.
+    """
+
+    def __init__(self, timeout=DEFAULT_OBSERVER_TIMEOUT, generate_full_events=False):
+        if (generate_full_events):
+            BaseObserver.__init__(self, emitter_class=InotifyFullEmitter, timeout=timeout)
+        else:
+            BaseObserver.__init__(self, emitter_class=InotifyEmitter,
+                                  timeout=timeout)

watchdog/observers/inotify_buffer.py

@@ -0,0 +1,98 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright 2014 Thomas Amland <thomas.amland@gmail.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+from watchdog.utils import BaseThread
+from watchdog.utils.delayed_queue import DelayedQueue
+from watchdog.observers.inotify_c import Inotify
+
+logger = logging.getLogger(__name__)
+
+
+class InotifyBuffer(BaseThread):
+    """A wrapper for `Inotify` that holds events for `delay` seconds. During
+    this time, IN_MOVED_FROM and IN_MOVED_TO events are paired.
+    """
+
+    delay = 0.5
+
+    def __init__(self, path, recursive=False):
+        BaseThread.__init__(self)
+        self._queue = DelayedQueue(self.delay)
+        self._inotify = Inotify(path, recursive)
+        self.start()
+
+    def read_event(self):
+        """Returns a single event or a tuple of from/to events in case of a
+        paired move event. If this buffer has been closed, immediately return
+        None.
+        """
+        return self._queue.get()
+
+    def on_thread_stop(self):
+        self._inotify.close()
+        self._queue.close()
+
+    def close(self):
+        self.stop()
+        self.join()
+
+    def _group_events(self, event_list):
+        """Group any matching move events"""
+        grouped = []
+        for inotify_event in event_list:
+            logger.debug("in-event %s", inotify_event)
+
+            def matching_from_event(event):
+                return (not isinstance(event, tuple) and event.is_moved_from
+                        and event.cookie == inotify_event.cookie)
+
+            if inotify_event.is_moved_to:
+                # Check if move_from is already in the buffer
+                for index, event in enumerate(grouped):
+                    if matching_from_event(event):
+                        grouped[index] = (event, inotify_event)
+                        break
+                else:
+                    # Check if move_from is in delayqueue already
+                    from_event = self._queue.remove(matching_from_event)
+                    if from_event is not None:
+                        grouped.append((from_event, inotify_event))
+                    else:
+                        logger.debug("could not find matching move_from event")
+                        grouped.append(inotify_event)
+            else:
+                grouped.append(inotify_event)
+        return grouped
+
+    def run(self):
+        """Read event from `inotify` and add them to `queue`. When reading a
+        IN_MOVE_TO event, remove the previous added matching IN_MOVE_FROM event
+        and add them back to the queue as a tuple.
+        """
+        deleted_self = False
+        while self.should_keep_running() and not deleted_self:
+            inotify_events = self._inotify.read_events()
+            grouped_events = self._group_events(inotify_events)
+            for inotify_event in grouped_events:
+                # Only add delay for unmatched move_from events
+                delay = not isinstance(inotify_event, tuple) and inotify_event.is_moved_from
+                self._queue.put(inotify_event, delay)
+
+                if not isinstance(inotify_event, tuple) and inotify_event.is_delete_self and \
+                        inotify_event.src_path == self._inotify.path:
+                    # Deleted the watched directory, stop watching for events
+                    deleted_self = True

watchdog/observers/inotify_c.py

@@ -0,0 +1,584 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import with_statement
+import os
+import errno
+import struct
+import threading
+import ctypes
+import ctypes.util
+from functools import reduce
+from ctypes import c_int, c_char_p, c_uint32
+from watchdog.utils import has_attribute
+from watchdog.utils import UnsupportedLibc
+from watchdog.utils.unicode_paths import decode
+
+
+def _load_libc():
+    libc_path = None
+    try:
+        libc_path = ctypes.util.find_library('c')
+    except (OSError, IOError, RuntimeError):
+        # Note: find_library will on some platforms raise these undocumented
+        # errors, e.g.on android IOError "No usable temporary directory found"
+        # will be raised.
+        pass
+
+    if libc_path is not None:
+        return ctypes.CDLL(libc_path)
+
+    # Fallbacks
+    try:
+        return ctypes.CDLL('libc.so')
+    except (OSError, IOError):
+        pass
+
+    try:
+        return ctypes.CDLL('libc.so.6')
+    except (OSError, IOError):
+        pass
+
+    # uClibc
+    try:
+        return ctypes.CDLL('libc.so.0')
+    except (OSError, IOError) as err:
+        raise err
+
+
+libc = _load_libc()
+
+if not has_attribute(libc, 'inotify_init') or \
+        not has_attribute(libc, 'inotify_add_watch') or \
+        not has_attribute(libc, 'inotify_rm_watch'):
+    raise UnsupportedLibc("Unsupported libc version found: %s" % libc._name)
+
+inotify_add_watch = ctypes.CFUNCTYPE(c_int, c_int, c_char_p, c_uint32, use_errno=True)(
+    ("inotify_add_watch", libc))
+
+inotify_rm_watch = ctypes.CFUNCTYPE(c_int, c_int, c_uint32, use_errno=True)(
+    ("inotify_rm_watch", libc))
+
+inotify_init = ctypes.CFUNCTYPE(c_int, use_errno=True)(
+    ("inotify_init", libc))
+
+
+class InotifyConstants(object):
+    # User-space events
+    IN_ACCESS = 0x00000001     # File was accessed.
+    IN_MODIFY = 0x00000002     # File was modified.
+    IN_ATTRIB = 0x00000004     # Meta-data changed.
+    IN_CLOSE_WRITE = 0x00000008     # Writable file was closed.
+    IN_CLOSE_NOWRITE = 0x00000010     # Unwritable file closed.
+    IN_OPEN = 0x00000020     # File was opened.
+    IN_MOVED_FROM = 0x00000040     # File was moved from X.
+    IN_MOVED_TO = 0x00000080     # File was moved to Y.
+    IN_CREATE = 0x00000100     # Subfile was created.
+    IN_DELETE = 0x00000200     # Subfile was deleted.
+    IN_DELETE_SELF = 0x00000400     # Self was deleted.
+    IN_MOVE_SELF = 0x00000800     # Self was moved.
+
+    # Helper user-space events.
+    IN_CLOSE = IN_CLOSE_WRITE | IN_CLOSE_NOWRITE  # Close.
+    IN_MOVE = IN_MOVED_FROM | IN_MOVED_TO  # Moves.
+
+    # Events sent by the kernel to a watch.
+    IN_UNMOUNT = 0x00002000     # Backing file system was unmounted.
+    IN_Q_OVERFLOW = 0x00004000     # Event queued overflowed.
+    IN_IGNORED = 0x00008000     # File was ignored.
+
+    # Special flags.
+    IN_ONLYDIR = 0x01000000     # Only watch the path if it's a directory.
+    IN_DONT_FOLLOW = 0x02000000     # Do not follow a symbolic link.
+    IN_EXCL_UNLINK = 0x04000000     # Exclude events on unlinked objects
+    IN_MASK_ADD = 0x20000000     # Add to the mask of an existing watch.
+    IN_ISDIR = 0x40000000     # Event occurred against directory.
+    IN_ONESHOT = 0x80000000     # Only send event once.
+
+    # All user-space events.
+    IN_ALL_EVENTS = reduce(
+        lambda x, y: x | y, [
+            IN_ACCESS,
+            IN_MODIFY,
+            IN_ATTRIB,
+            IN_CLOSE_WRITE,
+            IN_CLOSE_NOWRITE,
+            IN_OPEN,
+            IN_MOVED_FROM,
+            IN_MOVED_TO,
+            IN_DELETE,
+            IN_CREATE,
+            IN_DELETE_SELF,
+            IN_MOVE_SELF,
+        ])
+
+    # Flags for ``inotify_init1``
+    IN_CLOEXEC = 0x02000000
+    IN_NONBLOCK = 0x00004000
+
+
+# Watchdog's API cares only about these events.
+WATCHDOG_ALL_EVENTS = reduce(
+    lambda x, y: x | y, [
+        InotifyConstants.IN_MODIFY,
+        InotifyConstants.IN_ATTRIB,
+        InotifyConstants.IN_MOVED_FROM,
+        InotifyConstants.IN_MOVED_TO,
+        InotifyConstants.IN_CREATE,
+        InotifyConstants.IN_DELETE,
+        InotifyConstants.IN_DELETE_SELF,
+        InotifyConstants.IN_DONT_FOLLOW,
+    ])
+
+
+class inotify_event_struct(ctypes.Structure):
+    """
+    Structure representation of the inotify_event structure
+    (used in buffer size calculations)::
+
+        struct inotify_event {
+            __s32 wd;            /* watch descriptor */
+            __u32 mask;          /* watch mask */
+            __u32 cookie;        /* cookie to synchronize two events */
+            __u32 len;           /* length (including nulls) of name */
+            char  name[0];       /* stub for possible name */
+        };
+    """
+    _fields_ = [('wd', c_int),
+                ('mask', c_uint32),
+                ('cookie', c_uint32),
+                ('len', c_uint32),
+                ('name', c_char_p)]
+
+
+EVENT_SIZE = ctypes.sizeof(inotify_event_struct)
+DEFAULT_NUM_EVENTS = 2048
+DEFAULT_EVENT_BUFFER_SIZE = DEFAULT_NUM_EVENTS * (EVENT_SIZE + 16)
+
+
+class Inotify(object):
+    """
+    Linux inotify(7) API wrapper class.
+
+    :param path:
+        The directory path for which we want an inotify object.
+    :type path:
+        :class:`bytes`
+    :param recursive:
+        ``True`` if subdirectories should be monitored; ``False`` otherwise.
+    """
+
+    def __init__(self, path, recursive=False, event_mask=WATCHDOG_ALL_EVENTS):
+        # The file descriptor associated with the inotify instance.
+        inotify_fd = inotify_init()
+        if inotify_fd == -1:
+            Inotify._raise_error()
+        self._inotify_fd = inotify_fd
+        self._lock = threading.Lock()
+
+        # Stores the watch descriptor for a given path.
+        self._wd_for_path = dict()
+        self._path_for_wd = dict()
+
+        self._path = path
+        self._event_mask = event_mask
+        self._is_recursive = recursive
+        self._add_dir_watch(path, recursive, event_mask)
+        self._moved_from_events = dict()
+
+    @property
+    def event_mask(self):
+        """The event mask for this inotify instance."""
+        return self._event_mask
+
+    @property
+    def path(self):
+        """The path associated with the inotify instance."""
+        return self._path
+
+    @property
+    def is_recursive(self):
+        """Whether we are watching directories recursively."""
+        return self._is_recursive
+
+    @property
+    def fd(self):
+        """The file descriptor associated with the inotify instance."""
+        return self._inotify_fd
+
+    def clear_move_records(self):
+        """Clear cached records of MOVED_FROM events"""
+        self._moved_from_events = dict()
+
+    def source_for_move(self, destination_event):
+        """
+        The source path corresponding to the given MOVED_TO event.
+
+        If the source path is outside the monitored directories, None
+        is returned instead.
+        """
+        if destination_event.cookie in self._moved_from_events:
+            return self._moved_from_events[destination_event.cookie].src_path
+        else:
+            return None
+
+    def remember_move_from_event(self, event):
+        """
+        Save this event as the source event for future MOVED_TO events to
+        reference.
+        """
+        self._moved_from_events[event.cookie] = event
+
+    def add_watch(self, path):
+        """
+        Adds a watch for the given path.
+
+        :param path:
+            Path to begin monitoring.
+        """
+        with self._lock:
+            self._add_watch(path, self._event_mask)
+
+    def remove_watch(self, path):
+        """
+        Removes a watch for the given path.
+
+        :param path:
+            Path string for which the watch will be removed.
+        """
+        with self._lock:
+            wd = self._wd_for_path.pop(path)
+            del self._path_for_wd[wd]
+            if inotify_rm_watch(self._inotify_fd, wd) == -1:
+                Inotify._raise_error()
+
+    def close(self):
+        """
+        Closes the inotify instance and removes all associated watches.
+        """
+        with self._lock:
+            if self._path in self._wd_for_path:
+                wd = self._wd_for_path[self._path]
+                inotify_rm_watch(self._inotify_fd, wd)
+            os.close(self._inotify_fd)
+
+    def read_events(self, event_buffer_size=DEFAULT_EVENT_BUFFER_SIZE):
+        """
+        Reads events from inotify and yields them.
+        """
+        # HACK: We need to traverse the directory path
+        # recursively and simulate events for newly
+        # created subdirectories/files. This will handle
+        # mkdir -p foobar/blah/bar; touch foobar/afile
+
+        def _recursive_simulate(src_path):
+            events = []
+            for root, dirnames, filenames in os.walk(src_path):
+                for dirname in dirnames:
+                    try:
+                        full_path = os.path.join(root, dirname)
+                        wd_dir = self._add_watch(full_path, self._event_mask)
+                        e = InotifyEvent(
+                            wd_dir, InotifyConstants.IN_CREATE | InotifyConstants.IN_ISDIR, 0, dirname, full_path)
+                        events.append(e)
+                    except OSError:
+                        pass
+                for filename in filenames:
+                    full_path = os.path.join(root, filename)
+                    wd_parent_dir = self._wd_for_path[os.path.dirname(full_path)]
+                    e = InotifyEvent(
+                        wd_parent_dir, InotifyConstants.IN_CREATE, 0, filename, full_path)
+                    events.append(e)
+            return events
+
+        event_buffer = None
+        while True:
+            try:
+                event_buffer = os.read(self._inotify_fd, event_buffer_size)
+            except OSError as e:
+                if e.errno == errno.EINTR:
+                    continue
+            break
+
+        with self._lock:
+            event_list = []
+            for wd, mask, cookie, name in Inotify._parse_event_buffer(event_buffer):
+                if wd == -1:
+                    continue
+                wd_path = self._path_for_wd[wd]
+                src_path = os.path.join(wd_path, name) if name else wd_path  # avoid trailing slash
+                inotify_event = InotifyEvent(wd, mask, cookie, name, src_path)
+
+                if inotify_event.is_moved_from:
+                    self.remember_move_from_event(inotify_event)
+                elif inotify_event.is_moved_to:
+                    move_src_path = self.source_for_move(inotify_event)
+                    if move_src_path in self._wd_for_path:
+                        moved_wd = self._wd_for_path[move_src_path]
+                        del self._wd_for_path[move_src_path]
+                        self._wd_for_path[inotify_event.src_path] = moved_wd
+                        self._path_for_wd[moved_wd] = inotify_event.src_path
+                        if self.is_recursive:
+                            for _path, _wd in self._wd_for_path.copy().items():
+                                if _path.startswith(move_src_path + os.path.sep.encode()):
+                                    moved_wd = self._wd_for_path.pop(_path)
+                                    _move_to_path = _path.replace(move_src_path, inotify_event.src_path)
+                                    self._wd_for_path[_move_to_path] = moved_wd
+                                    self._path_for_wd[moved_wd] = _move_to_path
+                    src_path = os.path.join(wd_path, name)
+                    inotify_event = InotifyEvent(wd, mask, cookie, name, src_path)
+
+                if inotify_event.is_ignored:
+                    # Clean up book-keeping for deleted watches.
+                    path = self._path_for_wd.pop(wd)
+                    if self._wd_for_path[path] == wd:
+                        del self._wd_for_path[path]
+                    continue
+
+                event_list.append(inotify_event)
+
+                if (self.is_recursive and inotify_event.is_directory
+                        and inotify_event.is_create):
+
+                    # TODO: When a directory from another part of the
+                    # filesystem is moved into a watched directory, this
+                    # will not generate events for the directory tree.
+                    # We need to coalesce IN_MOVED_TO events and those
+                    # IN_MOVED_TO events which don't pair up with
+                    # IN_MOVED_FROM events should be marked IN_CREATE
+                    # instead relative to this directory.
+                    try:
+                        self._add_watch(src_path, self._event_mask)
+                    except OSError:
+                        continue
+
+                    event_list.extend(_recursive_simulate(src_path))
+
+        return event_list
+
+    # Non-synchronized methods.
+    def _add_dir_watch(self, path, recursive, mask):
+        """
+        Adds a watch (optionally recursively) for the given directory path
+        to monitor events specified by the mask.
+
+        :param path:
+            Path to monitor
+        :param recursive:
+            ``True`` to monitor recursively.
+        :param mask:
+            Event bit mask.
+        """
+        if not os.path.isdir(path):
+            raise OSError(errno.ENOTDIR, os.strerror(errno.ENOTDIR), path)
+        self._add_watch(path, mask)
+        if recursive:
+            for root, dirnames, _ in os.walk(path):
+                for dirname in dirnames:
+                    full_path = os.path.join(root, dirname)
+                    if os.path.islink(full_path):
+                        continue
+                    self._add_watch(full_path, mask)
+
+    def _add_watch(self, path, mask):
+        """
+        Adds a watch for the given path to monitor events specified by the
+        mask.
+
+        :param path:
+            Path to monitor
+        :param mask:
+            Event bit mask.
+        """
+        wd = inotify_add_watch(self._inotify_fd, path, mask)
+        if wd == -1:
+            Inotify._raise_error()
+        self._wd_for_path[path] = wd
+        self._path_for_wd[wd] = path
+        return wd
+
+    @staticmethod
+    def _raise_error():
+        """
+        Raises errors for inotify failures.
+        """
+        err = ctypes.get_errno()
+        if err == errno.ENOSPC:
+            raise OSError(errno.ENOSPC, "inotify watch limit reached")
+        elif err == errno.EMFILE:
+            raise OSError(errno.EMFILE, "inotify instance limit reached")
+        else:
+            raise OSError(err, os.strerror(err))
+
+    @staticmethod
+    def _parse_event_buffer(event_buffer):
+        """
+        Parses an event buffer of ``inotify_event`` structs returned by
+        inotify::
+
+            struct inotify_event {
+                __s32 wd;            /* watch descriptor */
+                __u32 mask;          /* watch mask */
+                __u32 cookie;        /* cookie to synchronize two events */
+                __u32 len;           /* length (including nulls) of name */
+                char  name[0];       /* stub for possible name */
+            };
+
+        The ``cookie`` member of this struct is used to pair two related
+        events, for example, it pairs an IN_MOVED_FROM event with an
+        IN_MOVED_TO event.
+        """
+        i = 0
+        while i + 16 <= len(event_buffer):
+            wd, mask, cookie, length = struct.unpack_from('iIII', event_buffer, i)
+            name = event_buffer[i + 16:i + 16 + length].rstrip(b'\0')
+            i += 16 + length
+            yield wd, mask, cookie, name
+
+
+class InotifyEvent(object):
+    """
+    Inotify event struct wrapper.
+
+    :param wd:
+        Watch descriptor
+    :param mask:
+        Event mask
+    :param cookie:
+        Event cookie
+    :param name:
+        Base name of the event source path.
+    :param src_path:
+        Full event source path.
+    """
+
+    def __init__(self, wd, mask, cookie, name, src_path):
+        self._wd = wd
+        self._mask = mask
+        self._cookie = cookie
+        self._name = name
+        self._src_path = src_path
+
+    @property
+    def src_path(self):
+        return self._src_path
+
+    @property
+    def wd(self):
+        return self._wd
+
+    @property
+    def mask(self):
+        return self._mask
+
+    @property
+    def cookie(self):
+        return self._cookie
+
+    @property
+    def name(self):
+        return self._name
+
+    @property
+    def is_modify(self):
+        return self._mask & InotifyConstants.IN_MODIFY > 0
+
+    @property
+    def is_close_write(self):
+        return self._mask & InotifyConstants.IN_CLOSE_WRITE > 0
+
+    @property
+    def is_close_nowrite(self):
+        return self._mask & InotifyConstants.IN_CLOSE_NOWRITE > 0
+
+    @property
+    def is_access(self):
+        return self._mask & InotifyConstants.IN_ACCESS > 0
+
+    @property
+    def is_delete(self):
+        return self._mask & InotifyConstants.IN_DELETE > 0
+
+    @property
+    def is_delete_self(self):
+        return self._mask & InotifyConstants.IN_DELETE_SELF > 0
+
+    @property
+    def is_create(self):
+        return self._mask & InotifyConstants.IN_CREATE > 0
+
+    @property
+    def is_moved_from(self):
+        return self._mask & InotifyConstants.IN_MOVED_FROM > 0
+
+    @property
+    def is_moved_to(self):
+        return self._mask & InotifyConstants.IN_MOVED_TO > 0
+
+    @property
+    def is_move(self):
+        return self._mask & InotifyConstants.IN_MOVE > 0
+
+    @property
+    def is_move_self(self):
+        return self._mask & InotifyConstants.IN_MOVE_SELF > 0
+
+    @property
+    def is_attrib(self):
+        return self._mask & InotifyConstants.IN_ATTRIB > 0
+
+    @property
+    def is_ignored(self):
+        return self._mask & InotifyConstants.IN_IGNORED > 0
+
+    @property
+    def is_directory(self):
+        # It looks like the kernel does not provide this information for
+        # IN_DELETE_SELF and IN_MOVE_SELF. In this case, assume it's a dir.
+        # See also: https://github.com/seb-m/pyinotify/blob/2c7e8f8/python2/pyinotify.py#L897
+        return (self.is_delete_self or self.is_move_self
+                or self._mask & InotifyConstants.IN_ISDIR > 0)
+
+    @property
+    def key(self):
+        return self._src_path, self._wd, self._mask, self._cookie, self._name
+
+    def __eq__(self, inotify_event):
+        return self.key == inotify_event.key
+
+    def __ne__(self, inotify_event):
+        return self.key == inotify_event.key
+
+    def __hash__(self):
+        return hash(self.key)
+
+    @staticmethod
+    def _get_mask_string(mask):
+        masks = []
+        for c in dir(InotifyConstants):
+            if c.startswith('IN_') and c not in ['IN_ALL_EVENTS', 'IN_CLOSE', 'IN_MOVE']:
+                c_val = getattr(InotifyConstants, c)
+                if mask & c_val:
+                    masks.append(c)
+        mask_string = '|'.join(masks)
+        return mask_string
+
+    def __repr__(self):
+        mask_string = self._get_mask_string(self.mask)
+        s = '<%s: src_path=%r, wd=%d, mask=%s, cookie=%d, name=%s>'
+        return s % (type(self).__name__, self.src_path, self.wd, mask_string,
+                    self.cookie, decode(self.name))

watchdog/observers/kqueue.py

@@ -0,0 +1,708 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+:module: watchdog.observers.kqueue
+:synopsis: ``kqueue(2)`` based emitter implementation.
+:author: yesudeep@google.com (Yesudeep Mangalapilly)
+:platforms: Mac OS X and BSD with kqueue(2).
+
+.. WARNING:: kqueue is a very heavyweight way to monitor file systems.
+             Each kqueue-detected directory modification triggers
+             a full directory scan. Traversing the entire directory tree
+             and opening file descriptors for all files will create
+             performance problems. We need to find a way to re-scan
+             only those directories which report changes and do a diff
+             between two sub-DirectorySnapshots perhaps.
+
+.. ADMONITION:: About OS X performance guidelines
+
+    Quote from the `Mac OS X File System Performance Guidelines`_:
+
+        "When you only want to track changes on a file or directory, be sure to
+        open it using the ``O_EVTONLY`` flag. This flag prevents the file or
+        directory from being marked as open or in use. This is important
+        if you are tracking files on a removable volume and the user tries to
+        unmount the volume. With this flag in place, the system knows it can
+        dismiss the volume. If you had opened the files or directories without
+        this flag, the volume would be marked as busy and would not be
+        unmounted."
+
+    ``O_EVTONLY`` is defined as ``0x8000`` in the OS X header files.
+    More information here: http://www.mlsite.net/blog/?p=2312
+
+Classes
+-------
+.. autoclass:: KqueueEmitter
+   :members:
+   :show-inheritance:
+
+Collections and Utility Classes
+-------------------------------
+.. autoclass:: KeventDescriptor
+   :members:
+   :show-inheritance:
+
+.. autoclass:: KeventDescriptorSet
+   :members:
+   :show-inheritance:
+
+.. _Mac OS X File System Performance Guidelines:
+    http://developer.apple.com/library/ios/#documentation/Performance/Conceptual/FileSystem/Articles/TrackingChanges.html#//apple_ref/doc/uid/20001993-CJBJFIDD
+
+"""
+
+from __future__ import with_statement
+from watchdog.utils import platform
+
+import threading
+import errno
+import stat
+import os
+import select
+
+from pathtools.path import absolute_path
+
+from watchdog.observers.api import (
+    BaseObserver,
+    EventEmitter,
+    DEFAULT_OBSERVER_TIMEOUT,
+    DEFAULT_EMITTER_TIMEOUT
+)
+
+from watchdog.utils.dirsnapshot import DirectorySnapshot
+
+from watchdog.events import (
+    DirMovedEvent,
+    DirDeletedEvent,
+    DirCreatedEvent,
+    DirModifiedEvent,
+    FileMovedEvent,
+    FileDeletedEvent,
+    FileCreatedEvent,
+    FileModifiedEvent,
+    EVENT_TYPE_MOVED,
+    EVENT_TYPE_DELETED,
+    EVENT_TYPE_CREATED
+)
+
+# Maximum number of events to process.
+MAX_EVENTS = 4096
+
+# O_EVTONLY value from the header files for OS X only.
+O_EVTONLY = 0x8000
+
+# Pre-calculated values for the kevent filter, flags, and fflags attributes.
+if platform.is_darwin():
+    WATCHDOG_OS_OPEN_FLAGS = O_EVTONLY
+else:
+    WATCHDOG_OS_OPEN_FLAGS = os.O_RDONLY | os.O_NONBLOCK
+WATCHDOG_KQ_FILTER = select.KQ_FILTER_VNODE
+WATCHDOG_KQ_EV_FLAGS = select.KQ_EV_ADD | select.KQ_EV_ENABLE | select.KQ_EV_CLEAR
+WATCHDOG_KQ_FFLAGS = (
+    select.KQ_NOTE_DELETE
+    | select.KQ_NOTE_WRITE
+    | select.KQ_NOTE_EXTEND
+    | select.KQ_NOTE_ATTRIB
+    | select.KQ_NOTE_LINK
+    | select.KQ_NOTE_RENAME
+    | select.KQ_NOTE_REVOKE
+)
+
+# Flag tests.
+
+
+def is_deleted(kev):
+    """Determines whether the given kevent represents deletion."""
+    return kev.fflags & select.KQ_NOTE_DELETE
+
+
+def is_modified(kev):
+    """Determines whether the given kevent represents modification."""
+    fflags = kev.fflags
+    return (fflags & select.KQ_NOTE_EXTEND) or (fflags & select.KQ_NOTE_WRITE)
+
+
+def is_attrib_modified(kev):
+    """Determines whether the given kevent represents attribute modification."""
+    return kev.fflags & select.KQ_NOTE_ATTRIB
+
+
+def is_renamed(kev):
+    """Determines whether the given kevent represents movement."""
+    return kev.fflags & select.KQ_NOTE_RENAME
+
+
+class KeventDescriptorSet(object):
+
+    """
+    Thread-safe kevent descriptor collection.
+    """
+
+    def __init__(self):
+        # Set of KeventDescriptor
+        self._descriptors = set()
+
+        # Descriptor for a given path.
+        self._descriptor_for_path = dict()
+
+        # Descriptor for a given fd.
+        self._descriptor_for_fd = dict()
+
+        # List of kevent objects.
+        self._kevents = list()
+
+        self._lock = threading.Lock()
+
+    @property
+    def kevents(self):
+        """
+        List of kevents monitored.
+        """
+        with self._lock:
+            return self._kevents
+
+    @property
+    def paths(self):
+        """
+        List of paths for which kevents have been created.
+        """
+        with self._lock:
+            return list(self._descriptor_for_path.keys())
+
+    def get_for_fd(self, fd):
+        """
+        Given a file descriptor, returns the kevent descriptor object
+        for it.
+
+        :param fd:
+            OS file descriptor.
+        :type fd:
+            ``int``
+        :returns:
+            A :class:`KeventDescriptor` object.
+        """
+        with self._lock:
+            return self._descriptor_for_fd[fd]
+
+    def get(self, path):
+        """
+        Obtains a :class:`KeventDescriptor` object for the specified path.
+
+        :param path:
+            Path for which the descriptor will be obtained.
+        """
+        with self._lock:
+            path = absolute_path(path)
+            return self._get(path)
+
+    def __contains__(self, path):
+        """
+        Determines whether a :class:`KeventDescriptor has been registered
+        for the specified path.
+
+        :param path:
+            Path for which the descriptor will be obtained.
+        """
+        with self._lock:
+            path = absolute_path(path)
+            return self._has_path(path)
+
+    def add(self, path, is_directory):
+        """
+        Adds a :class:`KeventDescriptor` to the collection for the given
+        path.
+
+        :param path:
+            The path for which a :class:`KeventDescriptor` object will be
+            added.
+        :param is_directory:
+            ``True`` if the path refers to a directory; ``False`` otherwise.
+        :type is_directory:
+            ``bool``
+        """
+        with self._lock:
+            path = absolute_path(path)
+            if not self._has_path(path):
+                self._add_descriptor(KeventDescriptor(path, is_directory))
+
+    def remove(self, path):
+        """
+        Removes the :class:`KeventDescriptor` object for the given path
+        if it already exists.
+
+        :param path:
+            Path for which the :class:`KeventDescriptor` object will be
+            removed.
+        """
+        with self._lock:
+            path = absolute_path(path)
+            if self._has_path(path):
+                self._remove_descriptor(self._get(path))
+
+    def clear(self):
+        """
+        Clears the collection and closes all open descriptors.
+        """
+        with self._lock:
+            for descriptor in self._descriptors:
+                descriptor.close()
+            self._descriptors.clear()
+            self._descriptor_for_fd.clear()
+            self._descriptor_for_path.clear()
+            self._kevents = []
+
+    # Thread-unsafe methods. Locking is provided at a higher level.
+    def _get(self, path):
+        """Returns a kevent descriptor for a given path."""
+        return self._descriptor_for_path[path]
+
+    def _has_path(self, path):
+        """Determines whether a :class:`KeventDescriptor` for the specified
+   path exists already in the collection."""
+        return path in self._descriptor_for_path
+
+    def _add_descriptor(self, descriptor):
+        """
+        Adds a descriptor to the collection.
+
+        :param descriptor:
+            An instance of :class:`KeventDescriptor` to be added.
+        """
+        self._descriptors.add(descriptor)
+        self._kevents.append(descriptor.kevent)
+        self._descriptor_for_path[descriptor.path] = descriptor
+        self._descriptor_for_fd[descriptor.fd] = descriptor
+
+    def _remove_descriptor(self, descriptor):
+        """
+        Removes a descriptor from the collection.
+
+        :param descriptor:
+            An instance of :class:`KeventDescriptor` to be removed.
+        """
+        self._descriptors.remove(descriptor)
+        del self._descriptor_for_fd[descriptor.fd]
+        del self._descriptor_for_path[descriptor.path]
+        self._kevents.remove(descriptor.kevent)
+        descriptor.close()
+
+
+class KeventDescriptor(object):
+
+    """
+    A kevent descriptor convenience data structure to keep together:
+
+        * kevent
+        * directory status
+        * path
+        * file descriptor
+
+    :param path:
+        Path string for which a kevent descriptor will be created.
+    :param is_directory:
+        ``True`` if the path refers to a directory; ``False`` otherwise.
+    :type is_directory:
+        ``bool``
+    """
+
+    def __init__(self, path, is_directory):
+        self._path = absolute_path(path)
+        self._is_directory = is_directory
+        self._fd = os.open(path, WATCHDOG_OS_OPEN_FLAGS)
+        self._kev = select.kevent(self._fd,
+                                  filter=WATCHDOG_KQ_FILTER,
+                                  flags=WATCHDOG_KQ_EV_FLAGS,
+                                  fflags=WATCHDOG_KQ_FFLAGS)
+
+    @property
+    def fd(self):
+        """OS file descriptor for the kevent descriptor."""
+        return self._fd
+
+    @property
+    def path(self):
+        """The path associated with the kevent descriptor."""
+        return self._path
+
+    @property
+    def kevent(self):
+        """The kevent object associated with the kevent descriptor."""
+        return self._kev
+
+    @property
+    def is_directory(self):
+        """Determines whether the kevent descriptor refers to a directory.
+
+        :returns:
+            ``True`` or ``False``
+        """
+        return self._is_directory
+
+    def close(self):
+        """
+        Closes the file descriptor associated with a kevent descriptor.
+        """
+        try:
+            os.close(self.fd)
+        except OSError:
+            pass
+
+    @property
+    def key(self):
+        return (self.path, self.is_directory)
+
+    def __eq__(self, descriptor):
+        return self.key == descriptor.key
+
+    def __ne__(self, descriptor):
+        return self.key != descriptor.key
+
+    def __hash__(self):
+        return hash(self.key)
+
+    def __repr__(self):
+        return "<%s: path=%s, is_directory=%s>"\
+            % (type(self).__name__, self.path, self.is_directory)
+
+
+class KqueueEmitter(EventEmitter):
+
+    """
+    kqueue(2)-based event emitter.
+
+    .. ADMONITION:: About ``kqueue(2)`` behavior and this implementation
+
+              ``kqueue(2)`` monitors file system events only for
+              open descriptors, which means, this emitter does a lot of
+              book-keeping behind the scenes to keep track of open
+              descriptors for every entry in the monitored directory tree.
+
+              This also means the number of maximum open file descriptors
+              on your system must be increased **manually**.
+              Usually, issuing a call to ``ulimit`` should suffice::
+
+                  ulimit -n 1024
+
+              Ensure that you pick a number that is larger than the
+              number of files you expect to be monitored.
+
+              ``kqueue(2)`` does not provide enough information about the
+              following things:
+
+              * The destination path of a file or directory that is renamed.
+              * Creation of a file or directory within a directory; in this
+                case, ``kqueue(2)`` only indicates a modified event on the
+                parent directory.
+
+              Therefore, this emitter takes a snapshot of the directory
+              tree when ``kqueue(2)`` detects a change on the file system
+              to be able to determine the above information.
+
+    :param event_queue:
+        The event queue to fill with events.
+    :param watch:
+        A watch object representing the directory to monitor.
+    :type watch:
+        :class:`watchdog.observers.api.ObservedWatch`
+    :param timeout:
+        Read events blocking timeout (in seconds).
+    :type timeout:
+        ``float``
+    """
+
+    def __init__(self, event_queue, watch, timeout=DEFAULT_EMITTER_TIMEOUT):
+        EventEmitter.__init__(self, event_queue, watch, timeout)
+
+        self._kq = select.kqueue()
+        self._lock = threading.RLock()
+
+        # A collection of KeventDescriptor.
+        self._descriptors = KeventDescriptorSet()
+
+        def walker_callback(path, stat_info, self=self):
+            self._register_kevent(path, stat.S_ISDIR(stat_info.st_mode))
+
+        self._snapshot = DirectorySnapshot(watch.path,
+                                           watch.is_recursive,
+                                           walker_callback)
+
+    def _register_kevent(self, path, is_directory):
+        """
+        Registers a kevent descriptor for the given path.
+
+        :param path:
+            Path for which a kevent descriptor will be created.
+        :param is_directory:
+            ``True`` if the path refers to a directory; ``False`` otherwise.
+        :type is_directory:
+            ``bool``
+        """
+        try:
+            self._descriptors.add(path, is_directory)
+        except OSError as e:
+            if e.errno == errno.ENOENT:
+                # Probably dealing with a temporary file that was created
+                # and then quickly deleted before we could open
+                # a descriptor for it. Therefore, simply queue a sequence
+                # of created and deleted events for the path.
+                # path = absolute_path(path)
+                # if is_directory:
+                #    self.queue_event(DirCreatedEvent(path))
+                #    self.queue_event(DirDeletedEvent(path))
+                # else:
+                #    self.queue_event(FileCreatedEvent(path))
+                #    self.queue_event(FileDeletedEvent(path))
+
+                # TODO: We could simply ignore these files.
+                # Locked files cause the python process to die with
+                # a bus error when we handle temporary files.
+                # eg. .git/index.lock when running tig operations.
+                # I don't fully understand this at the moment.
+                pass
+            else:
+                # All other errors are propagated.
+                raise
+
+    def _unregister_kevent(self, path):
+        """
+        Convenience function to close the kevent descriptor for a
+        specified kqueue-monitored path.
+
+        :param path:
+            Path for which the kevent descriptor will be closed.
+        """
+        self._descriptors.remove(path)
+
+    def queue_event(self, event):
+        """
+        Handles queueing a single event object.
+
+        :param event:
+            An instance of :class:`watchdog.events.FileSystemEvent`
+            or a subclass.
+        """
+        # Handles all the book keeping for queued events.
+        # We do not need to fire moved/deleted events for all subitems in
+        # a directory tree here, because this function is called by kqueue
+        # for all those events anyway.
+        EventEmitter.queue_event(self, event)
+        if event.event_type == EVENT_TYPE_CREATED:
+            self._register_kevent(event.src_path, event.is_directory)
+        elif event.event_type == EVENT_TYPE_MOVED:
+            self._unregister_kevent(event.src_path)
+            self._register_kevent(event.dest_path, event.is_directory)
+        elif event.event_type == EVENT_TYPE_DELETED:
+            self._unregister_kevent(event.src_path)
+
+    def _queue_dirs_modified(self,
+                             dirs_modified,
+                             ref_snapshot,
+                             new_snapshot):
+        """
+        Queues events for directory modifications by scanning the directory
+        for changes.
+
+        A scan is a comparison between two snapshots of the same directory
+        taken at two different times. This also determines whether files
+        or directories were created, which updated the modified timestamp
+        for the directory.
+        """
+        if dirs_modified:
+            for dir_modified in dirs_modified:
+                self.queue_event(DirModifiedEvent(dir_modified))
+            diff_events = new_snapshot - ref_snapshot
+            for file_created in diff_events.files_created:
+                self.queue_event(FileCreatedEvent(file_created))
+            for directory_created in diff_events.dirs_created:
+                self.queue_event(DirCreatedEvent(directory_created))
+
+    def _queue_events_except_renames_and_dir_modifications(self, event_list):
+        """
+        Queues events from the kevent list returned from the call to
+        :meth:`select.kqueue.control`.
+
+        .. NOTE:: Queues only the deletions, file modifications,
+                  attribute modifications. The other events, namely,
+                  file creation, directory modification, file rename,
+                  directory rename, directory creation, etc. are
+                  determined by comparing directory snapshots.
+        """
+        files_renamed = set()
+        dirs_renamed = set()
+        dirs_modified = set()
+
+        for kev in event_list:
+            descriptor = self._descriptors.get_for_fd(kev.ident)
+            src_path = descriptor.path
+
+            if is_deleted(kev):
+                if descriptor.is_directory:
+                    self.queue_event(DirDeletedEvent(src_path))
+                else:
+                    self.queue_event(FileDeletedEvent(src_path))
+            elif is_attrib_modified(kev):
+                if descriptor.is_directory:
+                    self.queue_event(DirModifiedEvent(src_path))
+                else:
+                    self.queue_event(FileModifiedEvent(src_path))
+            elif is_modified(kev):
+                if descriptor.is_directory:
+                    # When a directory is modified, it may be due to
+                    # sub-file/directory renames or new file/directory
+                    # creation. We determine all this by comparing
+                    # snapshots later.
+                    dirs_modified.add(src_path)
+                else:
+                    self.queue_event(FileModifiedEvent(src_path))
+            elif is_renamed(kev):
+                # Kqueue does not specify the destination names for renames
+                # to, so we have to process these after taking a snapshot
+                # of the directory.
+                if descriptor.is_directory:
+                    dirs_renamed.add(src_path)
+                else:
+                    files_renamed.add(src_path)
+        return files_renamed, dirs_renamed, dirs_modified
+
+    def _queue_renamed(self,
+                       src_path,
+                       is_directory,
+                       ref_snapshot,
+                       new_snapshot):
+        """
+        Compares information from two directory snapshots (one taken before
+        the rename operation and another taken right after) to determine the
+        destination path of the file system object renamed, and adds
+        appropriate events to the event queue.
+        """
+        try:
+            ref_stat_info = ref_snapshot.stat_info(src_path)
+        except KeyError:
+            # Probably caught a temporary file/directory that was renamed
+            # and deleted. Fires a sequence of created and deleted events
+            # for the path.
+            if is_directory:
+                self.queue_event(DirCreatedEvent(src_path))
+                self.queue_event(DirDeletedEvent(src_path))
+            else:
+                self.queue_event(FileCreatedEvent(src_path))
+                self.queue_event(FileDeletedEvent(src_path))
+                # We don't process any further and bail out assuming
+            # the event represents deletion/creation instead of movement.
+            return
+
+        try:
+            dest_path = absolute_path(
+                new_snapshot.path(ref_stat_info.st_ino))
+            if is_directory:
+                event = DirMovedEvent(src_path, dest_path)
+                # TODO: Do we need to fire moved events for the items
+                # inside the directory tree? Does kqueue does this
+                # all by itself? Check this and then enable this code
+                # only if it doesn't already.
+                # A: It doesn't. So I've enabled this block.
+                if self.watch.is_recursive:
+                    for sub_event in event.sub_moved_events():
+                        self.queue_event(sub_event)
+                self.queue_event(event)
+            else:
+                self.queue_event(FileMovedEvent(src_path, dest_path))
+        except KeyError:
+            # If the new snapshot does not have an inode for the
+            # old path, we haven't found the new name. Therefore,
+            # we mark it as deleted and remove unregister the path.
+            if is_directory:
+                self.queue_event(DirDeletedEvent(src_path))
+            else:
+                self.queue_event(FileDeletedEvent(src_path))
+
+    def _read_events(self, timeout=None):
+        """
+        Reads events from a call to the blocking
+        :meth:`select.kqueue.control()` method.
+
+        :param timeout:
+            Blocking timeout for reading events.
+        :type timeout:
+            ``float`` (seconds)
+        """
+        return self._kq.control(self._descriptors.kevents,
+                                MAX_EVENTS,
+                                timeout)
+
+    def queue_events(self, timeout):
+        """
+        Queues events by reading them from a call to the blocking
+        :meth:`select.kqueue.control()` method.
+
+        :param timeout:
+            Blocking timeout for reading events.
+        :type timeout:
+            ``float`` (seconds)
+        """
+        with self._lock:
+            try:
+                event_list = self._read_events(timeout)
+                files_renamed, dirs_renamed, dirs_modified = (
+                    self._queue_events_except_renames_and_dir_modifications(event_list))
+
+                # Take a fresh snapshot of the directory and update the
+                # saved snapshot.
+                new_snapshot = DirectorySnapshot(self.watch.path,
+                                                 self.watch.is_recursive)
+                ref_snapshot = self._snapshot
+                self._snapshot = new_snapshot
+
+                if files_renamed or dirs_renamed or dirs_modified:
+                    for src_path in files_renamed:
+                        self._queue_renamed(src_path,
+                                            False,
+                                            ref_snapshot,
+                                            new_snapshot)
+                    for src_path in dirs_renamed:
+                        self._queue_renamed(src_path,
+                                            True,
+                                            ref_snapshot,
+                                            new_snapshot)
+                    self._queue_dirs_modified(dirs_modified,
+                                              ref_snapshot,
+                                              new_snapshot)
+            except OSError as e:
+                if e.errno == errno.EBADF:
+                    # logging.debug(e)
+                    pass
+                else:
+                    raise
+
+    def on_thread_stop(self):
+        # Clean up.
+        with self._lock:
+            self._descriptors.clear()
+            self._kq.close()
+
+
+class KqueueObserver(BaseObserver):
+
+    """
+    Observer thread that schedules watching directories and dispatches
+    calls to event handlers.
+    """
+
+    def __init__(self, timeout=DEFAULT_OBSERVER_TIMEOUT):
+        BaseObserver.__init__(self, emitter_class=KqueueEmitter, timeout=timeout)

watchdog/observers/polling.py

@@ -0,0 +1,149 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+"""
+:module: watchdog.observers.polling
+:synopsis: Polling emitter implementation.
+:author: yesudeep@google.com (Yesudeep Mangalapilly)
+
+Classes
+-------
+.. autoclass:: PollingObserver
+   :members:
+   :show-inheritance:
+
+.. autoclass:: PollingObserverVFS
+   :members:
+   :show-inheritance:
+   :special-members:
+"""
+
+from __future__ import with_statement
+import threading
+from functools import partial
+from watchdog.utils import stat as default_stat
+from watchdog.utils.dirsnapshot import DirectorySnapshot, DirectorySnapshotDiff
+from watchdog.observers.api import (
+    EventEmitter,
+    BaseObserver,
+    DEFAULT_OBSERVER_TIMEOUT,
+    DEFAULT_EMITTER_TIMEOUT
+)
+
+from watchdog.events import (
+    DirMovedEvent,
+    DirDeletedEvent,
+    DirCreatedEvent,
+    DirModifiedEvent,
+    FileMovedEvent,
+    FileDeletedEvent,
+    FileCreatedEvent,
+    FileModifiedEvent
+)
+
+try:
+    from os import scandir
+except ImportError:
+    from os import listdir as scandir
+
+
+class PollingEmitter(EventEmitter):
+    """
+    Platform-independent emitter that polls a directory to detect file
+    system changes.
+    """
+
+    def __init__(self, event_queue, watch, timeout=DEFAULT_EMITTER_TIMEOUT,
+                 stat=default_stat, listdir=scandir):
+        EventEmitter.__init__(self, event_queue, watch, timeout)
+        self._snapshot = None
+        self._lock = threading.Lock()
+        self._take_snapshot = lambda: DirectorySnapshot(
+            self.watch.path, self.watch.is_recursive, stat=stat, listdir=listdir)
+
+    def on_thread_start(self):
+        self._snapshot = self._take_snapshot()
+
+    def queue_events(self, timeout):
+        # We don't want to hit the disk continuously.
+        # timeout behaves like an interval for polling emitters.
+        if self.stopped_event.wait(timeout):
+            return
+
+        with self._lock:
+            if not self.should_keep_running():
+                return
+
+            # Get event diff between fresh snapshot and previous snapshot.
+            # Update snapshot.
+            try:
+                new_snapshot = self._take_snapshot()
+            except OSError:
+                self.queue_event(DirDeletedEvent(self.watch.path))
+                self.stop()
+                return
+
+            events = DirectorySnapshotDiff(self._snapshot, new_snapshot)
+            self._snapshot = new_snapshot
+
+            # Files.
+            for src_path in events.files_deleted:
+                self.queue_event(FileDeletedEvent(src_path))
+            for src_path in events.files_modified:
+                self.queue_event(FileModifiedEvent(src_path))
+            for src_path in events.files_created:
+                self.queue_event(FileCreatedEvent(src_path))
+            for src_path, dest_path in events.files_moved:
+                self.queue_event(FileMovedEvent(src_path, dest_path))
+
+            # Directories.
+            for src_path in events.dirs_deleted:
+                self.queue_event(DirDeletedEvent(src_path))
+            for src_path in events.dirs_modified:
+                self.queue_event(DirModifiedEvent(src_path))
+            for src_path in events.dirs_created:
+                self.queue_event(DirCreatedEvent(src_path))
+            for src_path, dest_path in events.dirs_moved:
+                self.queue_event(DirMovedEvent(src_path, dest_path))
+
+
+class PollingObserver(BaseObserver):
+    """
+    Platform-independent observer that polls a directory to detect file
+    system changes.
+    """
+
+    def __init__(self, timeout=DEFAULT_OBSERVER_TIMEOUT):
+        BaseObserver.__init__(self, emitter_class=PollingEmitter, timeout=timeout)
+
+
+class PollingObserverVFS(BaseObserver):
+    """
+    File system independent observer that polls a directory to detect changes.
+    """
+
+    def __init__(self, stat, listdir, polling_interval=1):
+        """
+        :param stat: stat function. See ``os.stat`` for details.
+        :param listdir: listdir function. See ``os.listdir`` for details.
+        :type polling_interval: float
+        :param polling_interval: interval in seconds between polling the file system.
+        """
+        emitter_cls = partial(PollingEmitter, stat=stat, listdir=listdir)
+        BaseObserver.__init__(self, emitter_class=emitter_cls, timeout=polling_interval)

watchdog/observers/read_directory_changes.py

@@ -0,0 +1,136 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+# Copyright 2014 Thomas Amland
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import threading
+import os.path
+import time
+
+from watchdog.events import (
+    DirCreatedEvent,
+    DirMovedEvent,
+    DirModifiedEvent,
+    FileCreatedEvent,
+    FileDeletedEvent,
+    FileMovedEvent,
+    FileModifiedEvent,
+    generate_sub_moved_events,
+    generate_sub_created_events,
+)
+
+from watchdog.observers.api import (
+    EventEmitter,
+    BaseObserver,
+    DEFAULT_OBSERVER_TIMEOUT,
+    DEFAULT_EMITTER_TIMEOUT
+)
+
+from watchdog.observers.winapi import (
+    read_events,
+    get_directory_handle,
+    close_directory_handle,
+)
+
+
+# HACK:
+WATCHDOG_TRAVERSE_MOVED_DIR_DELAY = 1   # seconds
+
+
+class WindowsApiEmitter(EventEmitter):
+    """
+    Windows API-based emitter that uses ReadDirectoryChangesW
+    to detect file system changes for a watch.
+    """
+
+    def __init__(self, event_queue, watch, timeout=DEFAULT_EMITTER_TIMEOUT):
+        EventEmitter.__init__(self, event_queue, watch, timeout)
+        self._lock = threading.Lock()
+        self._handle = None
+
+    def on_thread_start(self):
+        self._handle = get_directory_handle(self.watch.path)
+
+    def on_thread_stop(self):
+        if self._handle:
+            close_directory_handle(self._handle)
+
+    def _read_events(self):
+        return read_events(self._handle, self.watch.path, self.watch.is_recursive)
+
+    def queue_events(self, timeout):
+        winapi_events = self._read_events()
+        with self._lock:
+            last_renamed_src_path = ""
+            for winapi_event in winapi_events:
+                src_path = os.path.join(self.watch.path, winapi_event.src_path)
+
+                if winapi_event.is_renamed_old:
+                    last_renamed_src_path = src_path
+                elif winapi_event.is_renamed_new:
+                    dest_path = src_path
+                    src_path = last_renamed_src_path
+                    if os.path.isdir(dest_path):
+                        event = DirMovedEvent(src_path, dest_path)
+                        if self.watch.is_recursive:
+                            # HACK: We introduce a forced delay before
+                            # traversing the moved directory. This will read
+                            # only file movement that finishes within this
+                            # delay time.
+                            time.sleep(WATCHDOG_TRAVERSE_MOVED_DIR_DELAY)
+                            # The following block of code may not
+                            # obtain moved events for the entire tree if
+                            # the I/O is not completed within the above
+                            # delay time. So, it's not guaranteed to work.
+                            # TODO: Come up with a better solution, possibly
+                            # a way to wait for I/O to complete before
+                            # queuing events.
+                            for sub_moved_event in generate_sub_moved_events(src_path, dest_path):
+                                self.queue_event(sub_moved_event)
+                        self.queue_event(event)
+                    else:
+                        self.queue_event(FileMovedEvent(src_path, dest_path))
+                elif winapi_event.is_modified:
+                    cls = DirModifiedEvent if os.path.isdir(src_path) else FileModifiedEvent
+                    self.queue_event(cls(src_path))
+                elif winapi_event.is_added:
+                    isdir = os.path.isdir(src_path)
+                    cls = DirCreatedEvent if isdir else FileCreatedEvent
+                    self.queue_event(cls(src_path))
+                    if isdir and self.watch.is_recursive:
+                        # If a directory is moved from outside the watched folder to inside it
+                        # we only get a created directory event out of it, not any events for its children
+                        # so use the same hack as for file moves to get the child events
+                        time.sleep(WATCHDOG_TRAVERSE_MOVED_DIR_DELAY)
+                        sub_events = generate_sub_created_events(src_path)
+                        for sub_created_event in sub_events:
+                            self.queue_event(sub_created_event)
+                elif winapi_event.is_removed:
+                    self.queue_event(FileDeletedEvent(src_path))
+                elif winapi_event.is_removed_self:
+                    self.stop()
+
+
+class WindowsApiObserver(BaseObserver):
+    """
+    Observer thread that schedules watching directories and dispatches
+    calls to event handlers.
+    """
+
+    def __init__(self, timeout=DEFAULT_OBSERVER_TIMEOUT):
+        BaseObserver.__init__(self, emitter_class=WindowsApiEmitter,
+                              timeout=timeout)

watchdog/observers/winapi.py

@@ -0,0 +1,389 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# winapi.py: Windows API-Python interface (removes dependency on pywin32)
+#
+# Copyright (C) 2007 Thomas Heller <theller@ctypes.org>
+# Copyright (C) 2010 Will McGugan <will@willmcgugan.com>
+# Copyright (C) 2010 Ryan Kelly <ryan@rfk.id.au>
+# Copyright (C) 2010 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright (C) 2014 Thomas Amland
+# 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.
+# * Neither the name of the organization nor the names of its contributors may
+#   be used to endorse or promote products derived from this software without
+#   specific prior written permission.
+#
+# 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.
+#
+# Portions of this code were taken from pyfilesystem, which uses the above
+# new BSD license.
+
+import ctypes.wintypes
+from functools import reduce
+
+LPVOID = ctypes.wintypes.LPVOID
+
+# Invalid handle value.
+INVALID_HANDLE_VALUE = ctypes.c_void_p(-1).value
+
+# File notification constants.
+FILE_NOTIFY_CHANGE_FILE_NAME = 0x01
+FILE_NOTIFY_CHANGE_DIR_NAME = 0x02
+FILE_NOTIFY_CHANGE_ATTRIBUTES = 0x04
+FILE_NOTIFY_CHANGE_SIZE = 0x08
+FILE_NOTIFY_CHANGE_LAST_WRITE = 0x010
+FILE_NOTIFY_CHANGE_LAST_ACCESS = 0x020
+FILE_NOTIFY_CHANGE_CREATION = 0x040
+FILE_NOTIFY_CHANGE_SECURITY = 0x0100
+
+FILE_FLAG_BACKUP_SEMANTICS = 0x02000000
+FILE_FLAG_OVERLAPPED = 0x40000000
+FILE_LIST_DIRECTORY = 1
+FILE_SHARE_READ = 0x01
+FILE_SHARE_WRITE = 0x02
+FILE_SHARE_DELETE = 0x04
+OPEN_EXISTING = 3
+
+VOLUME_NAME_NT = 0x02
+
+# File action constants.
+FILE_ACTION_CREATED = 1
+FILE_ACTION_DELETED = 2
+FILE_ACTION_MODIFIED = 3
+FILE_ACTION_RENAMED_OLD_NAME = 4
+FILE_ACTION_RENAMED_NEW_NAME = 5
+FILE_ACTION_DELETED_SELF = 0xFFFE
+FILE_ACTION_OVERFLOW = 0xFFFF
+
+# Aliases
+FILE_ACTION_ADDED = FILE_ACTION_CREATED
+FILE_ACTION_REMOVED = FILE_ACTION_DELETED
+FILE_ACTION_REMOVED_SELF = FILE_ACTION_DELETED_SELF
+
+THREAD_TERMINATE = 0x0001
+
+# IO waiting constants.
+WAIT_ABANDONED = 0x00000080
+WAIT_IO_COMPLETION = 0x000000C0
+WAIT_OBJECT_0 = 0x00000000
+WAIT_TIMEOUT = 0x00000102
+
+# Error codes
+ERROR_OPERATION_ABORTED = 995
+
+
+class OVERLAPPED(ctypes.Structure):
+    _fields_ = [('Internal', LPVOID),
+                ('InternalHigh', LPVOID),
+                ('Offset', ctypes.wintypes.DWORD),
+                ('OffsetHigh', ctypes.wintypes.DWORD),
+                ('Pointer', LPVOID),
+                ('hEvent', ctypes.wintypes.HANDLE),
+                ]
+
+
+def _errcheck_bool(value, func, args):
+    if not value:
+        raise ctypes.WinError()
+    return args
+
+
+def _errcheck_handle(value, func, args):
+    if not value:
+        raise ctypes.WinError()
+    if value == INVALID_HANDLE_VALUE:
+        raise ctypes.WinError()
+    return args
+
+
+def _errcheck_dword(value, func, args):
+    if value == 0xFFFFFFFF:
+        raise ctypes.WinError()
+    return args
+
+
+kernel32 = ctypes.WinDLL("kernel32")
+
+ReadDirectoryChangesW = kernel32.ReadDirectoryChangesW
+ReadDirectoryChangesW.restype = ctypes.wintypes.BOOL
+ReadDirectoryChangesW.errcheck = _errcheck_bool
+ReadDirectoryChangesW.argtypes = (
+    ctypes.wintypes.HANDLE,  # hDirectory
+    LPVOID,  # lpBuffer
+    ctypes.wintypes.DWORD,  # nBufferLength
+    ctypes.wintypes.BOOL,  # bWatchSubtree
+    ctypes.wintypes.DWORD,  # dwNotifyFilter
+    ctypes.POINTER(ctypes.wintypes.DWORD),  # lpBytesReturned
+    ctypes.POINTER(OVERLAPPED),  # lpOverlapped
+    LPVOID  # FileIOCompletionRoutine # lpCompletionRoutine
+)
+
+CreateFileW = kernel32.CreateFileW
+CreateFileW.restype = ctypes.wintypes.HANDLE
+CreateFileW.errcheck = _errcheck_handle
+CreateFileW.argtypes = (
+    ctypes.wintypes.LPCWSTR,  # lpFileName
+    ctypes.wintypes.DWORD,  # dwDesiredAccess
+    ctypes.wintypes.DWORD,  # dwShareMode
+    LPVOID,  # lpSecurityAttributes
+    ctypes.wintypes.DWORD,  # dwCreationDisposition
+    ctypes.wintypes.DWORD,  # dwFlagsAndAttributes
+    ctypes.wintypes.HANDLE  # hTemplateFile
+)
+
+CloseHandle = kernel32.CloseHandle
+CloseHandle.restype = ctypes.wintypes.BOOL
+CloseHandle.argtypes = (
+    ctypes.wintypes.HANDLE,  # hObject
+)
+
+CancelIoEx = kernel32.CancelIoEx
+CancelIoEx.restype = ctypes.wintypes.BOOL
+CancelIoEx.errcheck = _errcheck_bool
+CancelIoEx.argtypes = (
+    ctypes.wintypes.HANDLE,  # hObject
+    ctypes.POINTER(OVERLAPPED)  # lpOverlapped
+)
+
+CreateEvent = kernel32.CreateEventW
+CreateEvent.restype = ctypes.wintypes.HANDLE
+CreateEvent.errcheck = _errcheck_handle
+CreateEvent.argtypes = (
+    LPVOID,  # lpEventAttributes
+    ctypes.wintypes.BOOL,  # bManualReset
+    ctypes.wintypes.BOOL,  # bInitialState
+    ctypes.wintypes.LPCWSTR,  # lpName
+)
+
+SetEvent = kernel32.SetEvent
+SetEvent.restype = ctypes.wintypes.BOOL
+SetEvent.errcheck = _errcheck_bool
+SetEvent.argtypes = (
+    ctypes.wintypes.HANDLE,  # hEvent
+)
+
+WaitForSingleObjectEx = kernel32.WaitForSingleObjectEx
+WaitForSingleObjectEx.restype = ctypes.wintypes.DWORD
+WaitForSingleObjectEx.errcheck = _errcheck_dword
+WaitForSingleObjectEx.argtypes = (
+    ctypes.wintypes.HANDLE,  # hObject
+    ctypes.wintypes.DWORD,  # dwMilliseconds
+    ctypes.wintypes.BOOL,  # bAlertable
+)
+
+CreateIoCompletionPort = kernel32.CreateIoCompletionPort
+CreateIoCompletionPort.restype = ctypes.wintypes.HANDLE
+CreateIoCompletionPort.errcheck = _errcheck_handle
+CreateIoCompletionPort.argtypes = (
+    ctypes.wintypes.HANDLE,  # FileHandle
+    ctypes.wintypes.HANDLE,  # ExistingCompletionPort
+    LPVOID,  # CompletionKey
+    ctypes.wintypes.DWORD,  # NumberOfConcurrentThreads
+)
+
+GetQueuedCompletionStatus = kernel32.GetQueuedCompletionStatus
+GetQueuedCompletionStatus.restype = ctypes.wintypes.BOOL
+GetQueuedCompletionStatus.errcheck = _errcheck_bool
+GetQueuedCompletionStatus.argtypes = (
+    ctypes.wintypes.HANDLE,  # CompletionPort
+    LPVOID,  # lpNumberOfBytesTransferred
+    LPVOID,  # lpCompletionKey
+    ctypes.POINTER(OVERLAPPED),  # lpOverlapped
+    ctypes.wintypes.DWORD,  # dwMilliseconds
+)
+
+PostQueuedCompletionStatus = kernel32.PostQueuedCompletionStatus
+PostQueuedCompletionStatus.restype = ctypes.wintypes.BOOL
+PostQueuedCompletionStatus.errcheck = _errcheck_bool
+PostQueuedCompletionStatus.argtypes = (
+    ctypes.wintypes.HANDLE,  # CompletionPort
+    ctypes.wintypes.DWORD,  # lpNumberOfBytesTransferred
+    ctypes.wintypes.DWORD,  # lpCompletionKey
+    ctypes.POINTER(OVERLAPPED),  # lpOverlapped
+)
+
+
+GetFinalPathNameByHandleW = kernel32.GetFinalPathNameByHandleW
+GetFinalPathNameByHandleW.restype = ctypes.wintypes.DWORD
+GetFinalPathNameByHandleW.errcheck = _errcheck_dword
+GetFinalPathNameByHandleW.argtypes = (
+    ctypes.wintypes.HANDLE,  # hFile
+    ctypes.wintypes.LPWSTR,  # lpszFilePath
+    ctypes.wintypes.DWORD,  # cchFilePath
+    ctypes.wintypes.DWORD,  # DWORD
+)
+
+
+class FILE_NOTIFY_INFORMATION(ctypes.Structure):
+    _fields_ = [("NextEntryOffset", ctypes.wintypes.DWORD),
+                ("Action", ctypes.wintypes.DWORD),
+                ("FileNameLength", ctypes.wintypes.DWORD),
+                # ("FileName", (ctypes.wintypes.WCHAR * 1))]
+                ("FileName", (ctypes.c_char * 1))]
+
+
+LPFNI = ctypes.POINTER(FILE_NOTIFY_INFORMATION)
+
+
+# We don't need to recalculate these flags every time a call is made to
+# the win32 API functions.
+WATCHDOG_FILE_FLAGS = FILE_FLAG_BACKUP_SEMANTICS
+WATCHDOG_FILE_SHARE_FLAGS = reduce(
+    lambda x, y: x | y, [
+        FILE_SHARE_READ,
+        FILE_SHARE_WRITE,
+        FILE_SHARE_DELETE,
+    ])
+WATCHDOG_FILE_NOTIFY_FLAGS = reduce(
+    lambda x, y: x | y, [
+        FILE_NOTIFY_CHANGE_FILE_NAME,
+        FILE_NOTIFY_CHANGE_DIR_NAME,
+        FILE_NOTIFY_CHANGE_ATTRIBUTES,
+        FILE_NOTIFY_CHANGE_SIZE,
+        FILE_NOTIFY_CHANGE_LAST_WRITE,
+        FILE_NOTIFY_CHANGE_SECURITY,
+        FILE_NOTIFY_CHANGE_LAST_ACCESS,
+        FILE_NOTIFY_CHANGE_CREATION,
+    ])
+
+BUFFER_SIZE = 2048
+
+
+def _parse_event_buffer(readBuffer, nBytes):
+    results = []
+    while nBytes > 0:
+        fni = ctypes.cast(readBuffer, LPFNI)[0]
+        ptr = ctypes.addressof(fni) + FILE_NOTIFY_INFORMATION.FileName.offset
+        # filename = ctypes.wstring_at(ptr, fni.FileNameLength)
+        filename = ctypes.string_at(ptr, fni.FileNameLength)
+        results.append((fni.Action, filename.decode('utf-16')))
+        numToSkip = fni.NextEntryOffset
+        if numToSkip <= 0:
+            break
+        readBuffer = readBuffer[numToSkip:]
+        nBytes -= numToSkip  # numToSkip is long. nBytes should be long too.
+    return results
+
+
+def _is_observed_path_deleted(handle, path):
+    # Comparison of observed path and actual path, returned by
+    # GetFinalPathNameByHandleW. If directory moved to the trash bin, or
+    # deleted, actual path will not be equal to observed path.
+    buff = ctypes.create_unicode_buffer(BUFFER_SIZE)
+    GetFinalPathNameByHandleW(handle, buff, BUFFER_SIZE, VOLUME_NAME_NT)
+    return buff.value != path
+
+
+def _generate_observed_path_deleted_event():
+    # Create synthetic event for notify that observed directory is deleted
+    path = ctypes.create_unicode_buffer('.')
+    event = FILE_NOTIFY_INFORMATION(0, FILE_ACTION_DELETED_SELF, len(path), path.value)
+    event_size = ctypes.sizeof(event)
+    buff = ctypes.create_string_buffer(BUFFER_SIZE)
+    ctypes.memmove(buff, ctypes.addressof(event), event_size)
+    return buff, event_size
+
+
+def get_directory_handle(path):
+    """Returns a Windows handle to the specified directory path."""
+    return CreateFileW(path, FILE_LIST_DIRECTORY, WATCHDOG_FILE_SHARE_FLAGS,
+                       None, OPEN_EXISTING, WATCHDOG_FILE_FLAGS, None)
+
+
+def close_directory_handle(handle):
+    try:
+        CancelIoEx(handle, None)  # force ReadDirectoryChangesW to return
+        CloseHandle(handle)       # close directory handle
+    except WindowsError:
+        try:
+            CloseHandle(handle)   # close directory handle
+        except Exception:
+            return
+
+
+def read_directory_changes(handle, path, recursive):
+    """Read changes to the directory using the specified directory handle.
+
+    http://timgolden.me.uk/pywin32-docs/win32file__ReadDirectoryChangesW_meth.html
+    """
+    event_buffer = ctypes.create_string_buffer(BUFFER_SIZE)
+    nbytes = ctypes.wintypes.DWORD()
+    try:
+        ReadDirectoryChangesW(handle, ctypes.byref(event_buffer),
+                              len(event_buffer), recursive,
+                              WATCHDOG_FILE_NOTIFY_FLAGS,
+                              ctypes.byref(nbytes), None, None)
+    except WindowsError as e:
+        if e.winerror == ERROR_OPERATION_ABORTED:
+            return [], 0
+
+        # Handle the case when the root path is deleted
+        if _is_observed_path_deleted(handle, path):
+            return _generate_observed_path_deleted_event()
+
+        raise e
+
+    # Python 2/3 compat
+    try:
+        int_class = long
+    except NameError:
+        int_class = int
+    return event_buffer.raw, int_class(nbytes.value)
+
+
+class WinAPINativeEvent(object):
+    def __init__(self, action, src_path):
+        self.action = action
+        self.src_path = src_path
+
+    @property
+    def is_added(self):
+        return self.action == FILE_ACTION_CREATED
+
+    @property
+    def is_removed(self):
+        return self.action == FILE_ACTION_REMOVED
+
+    @property
+    def is_modified(self):
+        return self.action == FILE_ACTION_MODIFIED
+
+    @property
+    def is_renamed_old(self):
+        return self.action == FILE_ACTION_RENAMED_OLD_NAME
+
+    @property
+    def is_renamed_new(self):
+        return self.action == FILE_ACTION_RENAMED_NEW_NAME
+
+    @property
+    def is_removed_self(self):
+        return self.action == FILE_ACTION_REMOVED_SELF
+
+    def __repr__(self):
+        return ("<%s: action=%d, src_path=%r>" % (
+                type(self).__name__, self.action, self.src_path))
+
+
+def read_events(handle, path, recursive):
+    buf, nbytes = read_directory_changes(handle, path, recursive)
+    events = _parse_event_buffer(buf, nbytes)
+    return [WinAPINativeEvent(action, src_path) for action, src_path in events]

watchdog/tricks/__init__.py

@@ -0,0 +1,174 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+import os
+import signal
+import subprocess
+import time
+
+from watchdog.utils import echo, has_attribute
+from watchdog.events import PatternMatchingEventHandler
+
+
+class Trick(PatternMatchingEventHandler):
+
+    """Your tricks should subclass this class."""
+
+    @classmethod
+    def generate_yaml(cls):
+        context = dict(module_name=cls.__module__,
+                       klass_name=cls.__name__)
+        template_yaml = """- %(module_name)s.%(klass_name)s:
+  args:
+  - argument1
+  - argument2
+  kwargs:
+    patterns:
+    - "*.py"
+    - "*.js"
+    ignore_patterns:
+    - "version.py"
+    ignore_directories: false
+"""
+        return template_yaml % context
+
+
+class LoggerTrick(Trick):
+
+    """A simple trick that does only logs events."""
+
+    def on_any_event(self, event):
+        pass
+
+    @echo.echo
+    def on_modified(self, event):
+        pass
+
+    @echo.echo
+    def on_deleted(self, event):
+        pass
+
+    @echo.echo
+    def on_created(self, event):
+        pass
+
+    @echo.echo
+    def on_moved(self, event):
+        pass
+
+
+class ShellCommandTrick(Trick):
+
+    """Executes shell commands in response to matched events."""
+
+    def __init__(self, shell_command=None, patterns=None, ignore_patterns=None,
+                 ignore_directories=False, wait_for_process=False,
+                 drop_during_process=False):
+        super(ShellCommandTrick, self).__init__(patterns, ignore_patterns,
+                                                ignore_directories)
+        self.shell_command = shell_command
+        self.wait_for_process = wait_for_process
+        self.drop_during_process = drop_during_process
+        self.process = None
+
+    def on_any_event(self, event):
+        from string import Template
+
+        if self.drop_during_process and self.process and self.process.poll() is None:
+            return
+
+        if event.is_directory:
+            object_type = 'directory'
+        else:
+            object_type = 'file'
+
+        context = {
+            'watch_src_path': event.src_path,
+            'watch_dest_path': '',
+            'watch_event_type': event.event_type,
+            'watch_object': object_type,
+        }
+
+        if self.shell_command is None:
+            if has_attribute(event, 'dest_path'):
+                context.update({'dest_path': event.dest_path})
+                command = 'echo "${watch_event_type} ${watch_object} from ${watch_src_path} to ${watch_dest_path}"'
+            else:
+                command = 'echo "${watch_event_type} ${watch_object} ${watch_src_path}"'
+        else:
+            if has_attribute(event, 'dest_path'):
+                context.update({'watch_dest_path': event.dest_path})
+            command = self.shell_command
+
+        command = Template(command).safe_substitute(**context)
+        self.process = subprocess.Popen(command, shell=True)
+        if self.wait_for_process:
+            self.process.wait()
+
+
+class AutoRestartTrick(Trick):
+
+    """Starts a long-running subprocess and restarts it on matched events.
+
+    The command parameter is a list of command arguments, such as
+    ['bin/myserver', '-c', 'etc/myconfig.ini'].
+
+    Call start() after creating the Trick. Call stop() when stopping
+    the process.
+    """
+
+    def __init__(self, command, patterns=None, ignore_patterns=None,
+                 ignore_directories=False, stop_signal=signal.SIGINT,
+                 kill_after=10):
+        super(AutoRestartTrick, self).__init__(
+            patterns, ignore_patterns, ignore_directories)
+        self.command = command
+        self.stop_signal = stop_signal
+        self.kill_after = kill_after
+        self.process = None
+
+    def start(self):
+        self.process = subprocess.Popen(self.command, preexec_fn=os.setsid)
+
+    def stop(self):
+        if self.process is None:
+            return
+        try:
+            os.killpg(os.getpgid(self.process.pid), self.stop_signal)
+        except OSError:
+            # Process is already gone
+            pass
+        else:
+            kill_time = time.time() + self.kill_after
+            while time.time() < kill_time:
+                if self.process.poll() is not None:
+                    break
+                time.sleep(0.25)
+            else:
+                try:
+                    os.killpg(os.getpgid(self.process.pid), 9)
+                except OSError:
+                    # Process is already gone
+                    pass
+        self.process = None
+
+    @echo.echo
+    def on_any_event(self, event):
+        self.stop()
+        self.start()

watchdog/utils/__init__.py

@@ -0,0 +1,157 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+"""
+:module: watchdog.utils
+:synopsis: Utility classes and functions.
+:author: yesudeep@google.com (Yesudeep Mangalapilly)
+
+Classes
+-------
+.. autoclass:: BaseThread
+   :members:
+   :show-inheritance:
+   :inherited-members:
+
+"""
+import os
+import sys
+import threading
+from watchdog.utils import platform
+from watchdog.utils.compat import Event
+
+
+if sys.version_info[0] == 2 and platform.is_windows():
+    # st_ino is not implemented in os.stat on this platform
+    import win32stat
+    stat = win32stat.stat
+else:
+    stat = os.stat
+
+
+def has_attribute(ob, attribute):
+    """
+    :func:`hasattr` swallows exceptions. :func:`has_attribute` tests a Python object for the
+    presence of an attribute.
+
+    :param ob:
+        object to inspect
+    :param attribute:
+        ``str`` for the name of the attribute.
+    """
+    return getattr(ob, attribute, None) is not None
+
+
+class UnsupportedLibc(Exception):
+    pass
+
+
+class BaseThread(threading.Thread):
+    """ Convenience class for creating stoppable threads. """
+
+    def __init__(self):
+        threading.Thread.__init__(self)
+        if has_attribute(self, 'daemon'):
+            self.daemon = True
+        else:
+            self.setDaemon(True)
+        self._stopped_event = Event()
+
+        if not has_attribute(self._stopped_event, 'is_set'):
+            self._stopped_event.is_set = self._stopped_event.isSet
+
+    @property
+    def stopped_event(self):
+        return self._stopped_event
+
+    def should_keep_running(self):
+        """Determines whether the thread should continue running."""
+        return not self._stopped_event.is_set()
+
+    def on_thread_stop(self):
+        """Override this method instead of :meth:`stop()`.
+        :meth:`stop()` calls this method.
+
+        This method is called immediately after the thread is signaled to stop.
+        """
+        pass
+
+    def stop(self):
+        """Signals the thread to stop."""
+        self._stopped_event.set()
+        self.on_thread_stop()
+
+    def on_thread_start(self):
+        """Override this method instead of :meth:`start()`. :meth:`start()`
+        calls this method.
+
+        This method is called right before this thread is started and this
+        object’s run() method is invoked.
+        """
+        pass
+
+    def start(self):
+        self.on_thread_start()
+        threading.Thread.start(self)
+
+
+def load_module(module_name):
+    """Imports a module given its name and returns a handle to it."""
+    try:
+        __import__(module_name)
+    except ImportError:
+        raise ImportError('No module named %s' % module_name)
+    return sys.modules[module_name]
+
+
+def load_class(dotted_path):
+    """Loads and returns a class definition provided a dotted path
+    specification the last part of the dotted path is the class name
+    and there is at least one module name preceding the class name.
+
+    Notes:
+    You will need to ensure that the module you are trying to load
+    exists in the Python path.
+
+    Examples:
+    - module.name.ClassName    # Provided module.name is in the Python path.
+    - module.ClassName         # Provided module is in the Python path.
+
+    What won't work:
+    - ClassName
+    - modle.name.ClassName     # Typo in module name.
+    - module.name.ClasNam      # Typo in classname.
+    """
+    dotted_path_split = dotted_path.split('.')
+    if len(dotted_path_split) > 1:
+        klass_name = dotted_path_split[-1]
+        module_name = '.'.join(dotted_path_split[:-1])
+
+        module = load_module(module_name)
+        if has_attribute(module, klass_name):
+            klass = getattr(module, klass_name)
+            return klass
+            # Finally create and return an instance of the class
+            # return klass(*args, **kwargs)
+        else:
+            raise AttributeError('Module %s does not have class attribute %s' % (
+                                 module_name, klass_name))
+    else:
+        raise ValueError(
+            'Dotted module path %s must contain a module name and a classname' % dotted_path)

watchdog/utils/bricks.py

@@ -0,0 +1,102 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+"""
+Utility collections or "bricks".
+
+:module: watchdog.utils.bricks
+:author: yesudeep@google.com (Yesudeep Mangalapilly)
+:author: lalinsky@gmail.com (Lukáš Lalinský)
+:author: python@rcn.com (Raymond Hettinger)
+
+Classes
+=======
+.. autoclass:: OrderedSetQueue
+   :members:
+   :show-inheritance:
+   :inherited-members:
+
+.. autoclass:: OrderedSet
+
+"""
+
+from .compat import queue
+
+
+class SkipRepeatsQueue(queue.Queue):
+
+    """Thread-safe implementation of an special queue where a
+    put of the last-item put'd will be dropped.
+
+    The implementation leverages locking already implemented in the base class
+    redefining only the primitives.
+
+    Queued items must be immutable and hashable so that they can be used
+    as dictionary keys. You must implement **only read-only properties** and
+    the :meth:`Item.__hash__()`, :meth:`Item.__eq__()`, and
+    :meth:`Item.__ne__()` methods for items to be hashable.
+
+    An example implementation follows::
+
+        class Item(object):
+            def __init__(self, a, b):
+                self._a = a
+                self._b = b
+
+            @property
+            def a(self):
+                return self._a
+
+            @property
+            def b(self):
+                return self._b
+
+            def _key(self):
+                return (self._a, self._b)
+
+            def __eq__(self, item):
+                return self._key() == item._key()
+
+            def __ne__(self, item):
+                return self._key() != item._key()
+
+            def __hash__(self):
+                return hash(self._key())
+
+    based on the OrderedSetQueue below
+    """
+
+    def _init(self, maxsize):
+        queue.Queue._init(self, maxsize)
+        self._last_item = None
+
+    def _put(self, item):
+        if item != self._last_item:
+            queue.Queue._put(self, item)
+            self._last_item = item
+        else:
+            # `put` increments `unfinished_tasks` even if we did not put
+            # anything into the queue here
+            self.unfinished_tasks -= 1
+
+    def _get(self):
+        item = queue.Queue._get(self)
+        if item is self._last_item:
+            self._last_item = None
+        return item

watchdog/utils/compat.py

@@ -0,0 +1,25 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright 2014 Thomas Amland <thomas.amland@gmail.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+__all__ = ['queue', 'Event']
+
+try:
+    import queue
+except ImportError:
+    import Queue as queue
+
+
+from threading import Event

watchdog/utils/delayed_queue.py

@@ -0,0 +1,83 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright 2014 Thomas Amland <thomas.amland@gmail.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import time
+import threading
+from collections import deque
+
+
+class DelayedQueue(object):
+
+    def __init__(self, delay):
+        self.delay_sec = delay
+        self._lock = threading.Lock()
+        self._not_empty = threading.Condition(self._lock)
+        self._queue = deque()
+        self._closed = False
+
+    def put(self, element, delay=False):
+        """Add element to queue."""
+        self._lock.acquire()
+        self._queue.append((element, time.time(), delay))
+        self._not_empty.notify()
+        self._lock.release()
+
+    def close(self):
+        """Close queue, indicating no more items will be added."""
+        self._closed = True
+        # Interrupt the blocking _not_empty.wait() call in get
+        self._not_empty.acquire()
+        self._not_empty.notify()
+        self._not_empty.release()
+
+    def get(self):
+        """Remove and return an element from the queue, or this queue has been
+        closed raise the Closed exception.
+        """
+        while True:
+            # wait for element to be added to queue
+            self._not_empty.acquire()
+            while len(self._queue) == 0 and not self._closed:
+                self._not_empty.wait()
+
+            if self._closed:
+                self._not_empty.release()
+                return None
+            head, insert_time, delay = self._queue[0]
+            self._not_empty.release()
+
+            # wait for delay if required
+            if delay:
+                time_left = insert_time + self.delay_sec - time.time()
+                while time_left > 0:
+                    time.sleep(time_left)
+                    time_left = insert_time + self.delay_sec - time.time()
+
+            # return element if it's still in the queue
+            with self._lock:
+                if len(self._queue) > 0 and self._queue[0][0] is head:
+                    self._queue.popleft()
+                    return head
+
+    def remove(self, predicate):
+        """Remove and return the first items for which predicate is True,
+        ignoring delay."""
+        with self._lock:
+            for i, (elem, t, delay) in enumerate(self._queue):
+                if predicate(elem):
+                    del self._queue[i]
+                    return elem
+        return None

watchdog/utils/dirsnapshot.py

@@ -0,0 +1,337 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+# Copyright 2014 Thomas Amland <thomas.amland@gmail.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+:module: watchdog.utils.dirsnapshot
+:synopsis: Directory snapshots and comparison.
+:author: yesudeep@google.com (Yesudeep Mangalapilly)
+
+.. ADMONITION:: Where are the moved events? They "disappeared"
+
+        This implementation does not take partition boundaries
+        into consideration. It will only work when the directory
+        tree is entirely on the same file system. More specifically,
+        any part of the code that depends on inode numbers can
+        break if partition boundaries are crossed. In these cases,
+        the snapshot diff will represent file/directory movement as
+        created and deleted events.
+
+Classes
+-------
+.. autoclass:: DirectorySnapshot
+   :members:
+   :show-inheritance:
+
+.. autoclass:: DirectorySnapshotDiff
+   :members:
+   :show-inheritance:
+
+"""
+
+import errno
+import os
+from stat import S_ISDIR
+from watchdog.utils import stat as default_stat
+try:
+    from os import scandir
+except ImportError:
+    from os import listdir as scandir
+
+
+class DirectorySnapshotDiff(object):
+    """
+    Compares two directory snapshots and creates an object that represents
+    the difference between the two snapshots.
+
+    :param ref:
+        The reference directory snapshot.
+    :type ref:
+        :class:`DirectorySnapshot`
+    :param snapshot:
+        The directory snapshot which will be compared
+        with the reference snapshot.
+    :type snapshot:
+        :class:`DirectorySnapshot`
+    """
+
+    def __init__(self, ref, snapshot):
+        created = snapshot.paths - ref.paths
+        deleted = ref.paths - snapshot.paths
+
+        # check that all unchanged paths have the same inode
+        for path in ref.paths & snapshot.paths:
+            if ref.inode(path) != snapshot.inode(path):
+                created.add(path)
+                deleted.add(path)
+
+        # find moved paths
+        moved = set()
+        for path in set(deleted):
+            inode = ref.inode(path)
+            new_path = snapshot.path(inode)
+            if new_path:
+                # file is not deleted but moved
+                deleted.remove(path)
+                moved.add((path, new_path))
+
+        for path in set(created):
+            inode = snapshot.inode(path)
+            old_path = ref.path(inode)
+            if old_path:
+                created.remove(path)
+                moved.add((old_path, path))
+
+        # find modified paths
+        # first check paths that have not moved
+        modified = set()
+        for path in ref.paths & snapshot.paths:
+            if ref.inode(path) == snapshot.inode(path):
+                if ref.mtime(path) != snapshot.mtime(path) or ref.size(path) != snapshot.size(path):
+                    modified.add(path)
+
+        for (old_path, new_path) in moved:
+            if ref.mtime(old_path) != snapshot.mtime(new_path) or ref.size(old_path) != snapshot.size(new_path):
+                modified.add(old_path)
+
+        self._dirs_created = [path for path in created if snapshot.isdir(path)]
+        self._dirs_deleted = [path for path in deleted if ref.isdir(path)]
+        self._dirs_modified = [path for path in modified if ref.isdir(path)]
+        self._dirs_moved = [(frm, to) for (frm, to) in moved if ref.isdir(frm)]
+
+        self._files_created = list(created - set(self._dirs_created))
+        self._files_deleted = list(deleted - set(self._dirs_deleted))
+        self._files_modified = list(modified - set(self._dirs_modified))
+        self._files_moved = list(moved - set(self._dirs_moved))
+
+    def __str__(self):
+        return self.__repr__()
+
+    def __repr__(self):
+        fmt = (
+            '<{0} files(created={1}, deleted={2}, modified={3}, moved={4}),'
+            ' folders(created={5}, deleted={6}, modified={7}, moved={8})>'
+        )
+        return fmt.format(
+            type(self).__name__,
+            len(self._files_created),
+            len(self._files_deleted),
+            len(self._files_modified),
+            len(self._files_moved),
+            len(self._dirs_created),
+            len(self._dirs_deleted),
+            len(self._dirs_modified),
+            len(self._dirs_moved)
+        )
+
+    @property
+    def files_created(self):
+        """List of files that were created."""
+        return self._files_created
+
+    @property
+    def files_deleted(self):
+        """List of files that were deleted."""
+        return self._files_deleted
+
+    @property
+    def files_modified(self):
+        """List of files that were modified."""
+        return self._files_modified
+
+    @property
+    def files_moved(self):
+        """
+        List of files that were moved.
+
+        Each event is a two-tuple the first item of which is the path
+        that has been renamed to the second item in the tuple.
+        """
+        return self._files_moved
+
+    @property
+    def dirs_modified(self):
+        """
+        List of directories that were modified.
+        """
+        return self._dirs_modified
+
+    @property
+    def dirs_moved(self):
+        """
+        List of directories that were moved.
+
+        Each event is a two-tuple the first item of which is the path
+        that has been renamed to the second item in the tuple.
+        """
+        return self._dirs_moved
+
+    @property
+    def dirs_deleted(self):
+        """
+        List of directories that were deleted.
+        """
+        return self._dirs_deleted
+
+    @property
+    def dirs_created(self):
+        """
+        List of directories that were created.
+        """
+        return self._dirs_created
+
+
+class DirectorySnapshot(object):
+    """
+    A snapshot of stat information of files in a directory.
+
+    :param path:
+        The directory path for which a snapshot should be taken.
+    :type path:
+        ``str``
+    :param recursive:
+        ``True`` if the entire directory tree should be included in the
+        snapshot; ``False`` otherwise.
+    :type recursive:
+        ``bool``
+    :param walker_callback:
+        .. deprecated:: 0.7.2
+    :param stat:
+        Use custom stat function that returns a stat structure for path.
+        Currently only st_dev, st_ino, st_mode and st_mtime are needed.
+
+        A function with the signature ``walker_callback(path, stat_info)``
+        which will be called for every entry in the directory tree.
+    :param listdir:
+        Use custom listdir function. For details see ``os.scandir`` if available, else ``os.listdir``.
+    """
+
+    def __init__(self, path, recursive=True,
+                 walker_callback=(lambda p, s: None),
+                 stat=default_stat,
+                 listdir=scandir):
+        self.recursive = recursive
+        self.walker_callback = walker_callback
+        self.stat = stat
+        self.listdir = listdir
+
+        self._stat_info = {}
+        self._inode_to_path = {}
+
+        st = stat(path)
+        self._stat_info[path] = st
+        self._inode_to_path[(st.st_ino, st.st_dev)] = path
+
+        for p, st in self.walk(path):
+            i = (st.st_ino, st.st_dev)
+            self._inode_to_path[i] = p
+            self._stat_info[p] = st
+            walker_callback(p, st)
+
+    def walk(self, root):
+        try:
+            paths = [os.path.join(root, entry if isinstance(entry, str) else entry.name)
+                     for entry in self.listdir(root)]
+        except OSError as e:
+            # Directory may have been deleted between finding it in the directory
+            # list of its parent and trying to delete its contents. If this
+            # happens we treat it as empty. Likewise if the directory was replaced
+            # with a file of the same name (less likely, but possible).
+            if e.errno in (errno.ENOENT, errno.ENOTDIR, errno.EINVAL):
+                return
+            else:
+                raise
+
+        entries = []
+        for p in paths:
+            try:
+                entry = (p, self.stat(p))
+                entries.append(entry)
+                yield entry
+            except OSError:
+                continue
+
+        if self.recursive:
+            for path, st in entries:
+                try:
+                    if S_ISDIR(st.st_mode):
+                        for entry in self.walk(path):
+                            yield entry
+                except (IOError, OSError) as e:
+                    # IOError for Python 2
+                    # OSError for Python 3
+                    # (should be only PermissionError when dropping Python 2 support)
+                    if e.errno != errno.EACCES:
+                        raise
+
+    @property
+    def paths(self):
+        """
+        Set of file/directory paths in the snapshot.
+        """
+        return set(self._stat_info.keys())
+
+    def path(self, id):
+        """
+        Returns path for id. None if id is unknown to this snapshot.
+        """
+        return self._inode_to_path.get(id)
+
+    def inode(self, path):
+        """ Returns an id for path. """
+        st = self._stat_info[path]
+        return (st.st_ino, st.st_dev)
+
+    def isdir(self, path):
+        return S_ISDIR(self._stat_info[path].st_mode)
+
+    def mtime(self, path):
+        return self._stat_info[path].st_mtime
+
+    def size(self, path):
+        return self._stat_info[path].st_size
+
+    def stat_info(self, path):
+        """
+        Returns a stat information object for the specified path from
+        the snapshot.
+
+        Attached information is subject to change. Do not use unless
+        you specify `stat` in constructor. Use :func:`inode`, :func:`mtime`,
+        :func:`isdir` instead.
+
+        :param path:
+            The path for which stat information should be obtained
+            from a snapshot.
+        """
+        return self._stat_info[path]
+
+    def __sub__(self, previous_dirsnap):
+        """Allow subtracting a DirectorySnapshot object instance from
+        another.
+
+        :returns:
+            A :class:`DirectorySnapshotDiff` object.
+        """
+        return DirectorySnapshotDiff(previous_dirsnap, self)
+
+    def __str__(self):
+        return self.__repr__()
+
+    def __repr__(self):
+        return str(self._stat_info)

watchdog/utils/echo.py

@@ -0,0 +1,162 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# echo.py: Tracing function calls using Python decorators.
+#
+# Written by Thomas Guest <tag@wordaligned.org>
+# Please see http://wordaligned.org/articles/echo
+#
+# Place into the public domain.
+
+""" Echo calls made to functions and methods in a module.
+
+"Echoing" a function call means printing out the name of the function
+and the values of its arguments before making the call (which is more
+commonly referred to as "tracing", but Python already has a trace module).
+
+Example: to echo calls made to functions in "my_module" do:
+
+  import echo
+  import my_module
+  echo.echo_module(my_module)
+
+Example: to echo calls made to functions in "my_module.my_class" do:
+
+  echo.echo_class(my_module.my_class)
+
+Alternatively, echo.echo can be used to decorate functions. Calls to the
+decorated function will be echoed.
+
+Example:
+
+  @echo.echo
+  def my_function(args):
+      pass
+"""
+import inspect
+import sys
+
+
+def name(item):
+    " Return an item's name. "
+    return item.__name__
+
+
+def is_classmethod(instancemethod, klass):
+    " Determine if an instancemethod is a classmethod. "
+    return inspect.ismethod(instancemethod) and instancemethod.__self__ is klass
+
+
+def is_static_method(method, klass):
+    """Returns True if method is an instance method of klass."""
+    for c in klass.mro():
+        if name(method) in c.__dict__:
+            return isinstance(c.__dict__[name(method)], staticmethod)
+    else:
+        return False
+
+
+def is_class_private_name(name):
+    " Determine if a name is a class private name. "
+    # Exclude system defined names such as __init__, __add__ etc
+    return name.startswith("__") and not name.endswith("__")
+
+
+def method_name(method):
+    """ Return a method's name.
+
+    This function returns the name the method is accessed by from
+    outside the class (i.e. it prefixes "private" methods appropriately).
+    """
+    mname = name(method)
+    if is_class_private_name(mname):
+        mname = "_%s%s" % (name(method.__self__.__class__), mname)
+    return mname
+
+
+def format_arg_value(arg_val):
+    """ Return a string representing a (name, value) pair.
+
+    >>> format_arg_value(('x', (1, 2, 3)))
+    'x=(1, 2, 3)'
+    """
+    arg, val = arg_val
+    return "%s=%r" % (arg, val)
+
+
+def echo(fn, write=sys.stdout.write):
+    """ Echo calls to a function.
+
+    Returns a decorated version of the input function which "echoes" calls
+    made to it by writing out the function's name and the arguments it was
+    called with.
+    """
+    import functools
+    # Unpack function's arg count, arg names, arg defaults
+    code = fn.__code__
+    argcount = code.co_argcount
+    argnames = code.co_varnames[:argcount]
+    fn_defaults = fn.__defaults__ or list()
+    argdefs = dict(list(zip(argnames[-len(fn_defaults):], fn_defaults)))
+
+    @functools.wraps(fn)
+    def wrapped(*v, **k):
+        # Collect function arguments by chaining together positional,
+        # defaulted, extra positional and keyword arguments.
+        positional = list(map(format_arg_value, list(zip(argnames, v))))
+        defaulted = [format_arg_value((a, argdefs[a]))
+                     for a in argnames[len(v):] if a not in k]
+        nameless = list(map(repr, v[argcount:]))
+        keyword = list(map(format_arg_value, list(k.items())))
+        args = positional + defaulted + nameless + keyword
+        write("%s(%s)\n" % (name(fn), ", ".join(args)))
+        return fn(*v, **k)
+
+    return wrapped
+
+
+def echo_instancemethod(klass, method, write=sys.stdout.write):
+    """ Change an instancemethod so that calls to it are echoed.
+
+    Replacing a classmethod is a little more tricky.
+    See: http://www.python.org/doc/current/ref/types.html
+    """
+    mname = method_name(method)
+    never_echo = "__str__", "__repr__",  # Avoid recursion printing method calls
+    if mname in never_echo:
+        pass
+    elif is_classmethod(method, klass):
+        setattr(klass, mname, classmethod(echo(method.__func__, write)))
+    else:
+        setattr(klass, mname, echo(method, write))
+
+
+def echo_class(klass, write=sys.stdout.write):
+    """ Echo calls to class methods and static functions
+    """
+    for _, method in inspect.getmembers(klass, inspect.ismethod):
+        # In python 3 only class methods are returned here, but in python2 instance methods are too.
+        echo_instancemethod(klass, method, write)
+    for _, fn in inspect.getmembers(klass, inspect.isfunction):
+        if is_static_method(fn, klass):
+            setattr(klass, name(fn), staticmethod(echo(fn, write)))
+        else:
+            # It's not a class or a static method, so it must be an instance method.
+            # This should only be called in python 3, because in python 3 instance methods are considered functions.
+            echo_instancemethod(klass, fn, write)
+
+
+def echo_module(mod, write=sys.stdout.write):
+    """ Echo calls to functions and methods in a module.
+    """
+    for fname, fn in inspect.getmembers(mod, inspect.isfunction):
+        setattr(mod, fname, echo(fn, write))
+    for _, klass in inspect.getmembers(mod, inspect.isclass):
+        echo_class(klass, write)
+
+
+if __name__ == "__main__":
+    import doctest
+
+    optionflags = doctest.ELLIPSIS
+    doctest.testfile('echoexample.txt', optionflags=optionflags)
+    doctest.testmod(optionflags=optionflags)

watchdog/utils/platform.py

@@ -0,0 +1,58 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+import sys
+
+PLATFORM_WINDOWS = 'windows'
+PLATFORM_LINUX = 'linux'
+PLATFORM_BSD = 'bsd'
+PLATFORM_DARWIN = 'darwin'
+PLATFORM_UNKNOWN = 'unknown'
+
+
+def get_platform_name():
+    if sys.platform.startswith("win"):
+        return PLATFORM_WINDOWS
+    elif sys.platform.startswith('darwin'):
+        return PLATFORM_DARWIN
+    elif sys.platform.startswith('linux'):
+        return PLATFORM_LINUX
+    elif sys.platform.startswith(('dragonfly', 'freebsd', 'netbsd', 'openbsd', 'bsd')):
+        return PLATFORM_BSD
+    else:
+        return PLATFORM_UNKNOWN
+
+
+__platform__ = get_platform_name()
+
+
+def is_linux():
+    return __platform__ == PLATFORM_LINUX
+
+
+def is_bsd():
+    return __platform__ == PLATFORM_BSD
+
+
+def is_darwin():
+    return __platform__ == PLATFORM_DARWIN
+
+
+def is_windows():
+    return __platform__ == PLATFORM_WINDOWS

watchdog/utils/unicode_paths.py

@@ -0,0 +1,64 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright (c) 2013 Will Bond <will@wbond.net>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+
+import sys
+
+from watchdog.utils import platform
+
+try:
+    # Python 2
+    str_cls = unicode
+    bytes_cls = str
+except NameError:
+    # Python 3
+    str_cls = str
+    bytes_cls = bytes
+
+
+# This is used by Linux when the locale seems to be improperly set. UTF-8 tends
+# to be the encoding used by all distros, so this is a good fallback.
+fs_fallback_encoding = 'utf-8'
+fs_encoding = sys.getfilesystemencoding() or fs_fallback_encoding
+
+
+def encode(path):
+    if isinstance(path, str_cls):
+        try:
+            path = path.encode(fs_encoding, 'strict')
+        except UnicodeEncodeError:
+            if not platform.is_linux():
+                raise
+            path = path.encode(fs_fallback_encoding, 'strict')
+    return path
+
+
+def decode(path):
+    if isinstance(path, bytes_cls):
+        try:
+            path = path.decode(fs_encoding, 'strict')
+        except UnicodeDecodeError:
+            if not platform.is_linux():
+                raise
+            path = path.decode(fs_fallback_encoding, 'strict')
+    return path

watchdog/utils/win32stat.py

@@ -0,0 +1,131 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright 2014 Thomas Amland <thomas.amland@gmail.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+:module: watchdog.utils.win32stat
+:synopsis: Implementation of stat with st_ino and st_dev support.
+
+Functions
+---------
+
+.. autofunction:: stat
+
+"""
+
+import ctypes
+import ctypes.wintypes
+import stat as stdstat
+from collections import namedtuple
+
+
+INVALID_HANDLE_VALUE = ctypes.c_void_p(-1).value
+OPEN_EXISTING = 3
+FILE_READ_ATTRIBUTES = 0x80
+FILE_ATTRIBUTE_NORMAL = 0x80
+FILE_ATTRIBUTE_READONLY = 0x1
+FILE_ATTRIBUTE_DIRECTORY = 0x10
+FILE_FLAG_BACKUP_SEMANTICS = 0x02000000
+FILE_FLAG_OPEN_REPARSE_POINT = 0x00200000
+
+
+class FILETIME(ctypes.Structure):
+    _fields_ = [("dwLowDateTime", ctypes.wintypes.DWORD),
+                ("dwHighDateTime", ctypes.wintypes.DWORD)]
+
+
+class BY_HANDLE_FILE_INFORMATION(ctypes.Structure):
+    _fields_ = [('dwFileAttributes', ctypes.wintypes.DWORD),
+                ('ftCreationTime', FILETIME),
+                ('ftLastAccessTime', FILETIME),
+                ('ftLastWriteTime', FILETIME),
+                ('dwVolumeSerialNumber', ctypes.wintypes.DWORD),
+                ('nFileSizeHigh', ctypes.wintypes.DWORD),
+                ('nFileSizeLow', ctypes.wintypes.DWORD),
+                ('nNumberOfLinks', ctypes.wintypes.DWORD),
+                ('nFileIndexHigh', ctypes.wintypes.DWORD),
+                ('nFileIndexLow', ctypes.wintypes.DWORD)]
+
+
+kernel32 = ctypes.WinDLL("kernel32")
+
+CreateFile = kernel32.CreateFileW
+CreateFile.restype = ctypes.wintypes.HANDLE
+CreateFile.argtypes = (
+    ctypes.c_wchar_p,
+    ctypes.wintypes.DWORD,
+    ctypes.wintypes.DWORD,
+    ctypes.c_void_p,
+    ctypes.wintypes.DWORD,
+    ctypes.wintypes.DWORD,
+    ctypes.wintypes.HANDLE,
+)
+
+GetFileInformationByHandle = kernel32.GetFileInformationByHandle
+GetFileInformationByHandle.restype = ctypes.wintypes.BOOL
+GetFileInformationByHandle.argtypes = (
+    ctypes.wintypes.HANDLE,
+    ctypes.wintypes.POINTER(BY_HANDLE_FILE_INFORMATION),
+)
+
+CloseHandle = kernel32.CloseHandle
+CloseHandle.restype = ctypes.wintypes.BOOL
+CloseHandle.argtypes = (ctypes.wintypes.HANDLE,)
+
+
+StatResult = namedtuple('StatResult', 'st_dev st_ino st_mode st_mtime st_size')
+
+
+def _to_mode(attr):
+    m = 0
+    if (attr & FILE_ATTRIBUTE_DIRECTORY):
+        m |= stdstat.S_IFDIR | 0o111
+    else:
+        m |= stdstat.S_IFREG
+    if (attr & FILE_ATTRIBUTE_READONLY):
+        m |= 0o444
+    else:
+        m |= 0o666
+    return m
+
+
+def _to_unix_time(ft):
+    t = (ft.dwHighDateTime) << 32 | ft.dwLowDateTime
+    return (t / 10000000) - 11644473600
+
+
+def stat(path):
+    hfile = CreateFile(path,
+                       FILE_READ_ATTRIBUTES,
+                       0,
+                       None,
+                       OPEN_EXISTING,
+                       FILE_ATTRIBUTE_NORMAL
+                       | FILE_FLAG_BACKUP_SEMANTICS
+                       | FILE_FLAG_OPEN_REPARSE_POINT,
+                       None)
+    if hfile == INVALID_HANDLE_VALUE:
+        raise ctypes.WinError()
+    info = BY_HANDLE_FILE_INFORMATION()
+    r = GetFileInformationByHandle(hfile, info)
+    CloseHandle(hfile)
+    if not r:
+        raise ctypes.WinError()
+    return StatResult(st_dev=info.dwVolumeSerialNumber,
+                      st_ino=(info.nFileIndexHigh << 32) + info.nFileIndexLow,
+                      st_mode=_to_mode(info.dwFileAttributes),
+                      st_mtime=_to_unix_time(info.ftLastWriteTime),
+                      st_size=(info.nFileSizeHigh << 32) + info.nFileSizeLow
+                      )

watchdog/version.py

@@ -0,0 +1,28 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+# When updating this version number, please update the
+# ``docs/source/global.rst.inc`` file as well.
+VERSION_MAJOR = 0
+VERSION_MINOR = 9
+VERSION_BUILD = 0
+VERSION_INFO = (VERSION_MAJOR, VERSION_MINOR, VERSION_BUILD)
+VERSION_STRING = "%d.%d.%d" % VERSION_INFO
+
+__version__ = VERSION_INFO

watchdog/watchmedo.py

@@ -0,0 +1,580 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>
+# Copyright 2012 Google, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+:module: watchdog.watchmedo
+:author: yesudeep@google.com (Yesudeep Mangalapilly)
+:synopsis: ``watchmedo`` shell script utility.
+"""
+
+import os.path
+import sys
+import yaml
+import time
+import logging
+
+try:
+    from cStringIO import StringIO
+except ImportError:
+    try:
+        from StringIO import StringIO
+    except ImportError:
+        from io import StringIO
+
+from argh import arg, aliases, ArghParser, expects_obj
+from watchdog.version import VERSION_STRING
+from watchdog.utils import load_class
+
+
+logging.basicConfig(level=logging.INFO)
+
+CONFIG_KEY_TRICKS = 'tricks'
+CONFIG_KEY_PYTHON_PATH = 'python-path'
+
+
+def path_split(pathname_spec, separator=os.pathsep):
+    """
+    Splits a pathname specification separated by an OS-dependent separator.
+
+    :param pathname_spec:
+        The pathname specification.
+    :param separator:
+        (OS Dependent) `:` on Unix and `;` on Windows or user-specified.
+    """
+    return list(pathname_spec.split(separator))
+
+
+def add_to_sys_path(pathnames, index=0):
+    """
+    Adds specified paths at specified index into the sys.path list.
+
+    :param paths:
+        A list of paths to add to the sys.path
+    :param index:
+        (Default 0) The index in the sys.path list where the paths will be
+        added.
+    """
+    for pathname in pathnames[::-1]:
+        sys.path.insert(index, pathname)
+
+
+def load_config(tricks_file_pathname):
+    """
+    Loads the YAML configuration from the specified file.
+
+    :param tricks_file_path:
+        The path to the tricks configuration file.
+    :returns:
+        A dictionary of configuration information.
+    """
+    with open(tricks_file_pathname, 'rb') as f:
+        return yaml.safe_load(f.read())
+
+
+def parse_patterns(patterns_spec, ignore_patterns_spec, separator=';'):
+    """
+    Parses pattern argument specs and returns a two-tuple of
+    (patterns, ignore_patterns).
+    """
+    patterns = patterns_spec.split(separator)
+    ignore_patterns = ignore_patterns_spec.split(separator)
+    if ignore_patterns == ['']:
+        ignore_patterns = []
+    return (patterns, ignore_patterns)
+
+
+def observe_with(observer, event_handler, pathnames, recursive):
+    """
+    Single observer thread with a scheduled path and event handler.
+
+    :param observer:
+        The observer thread.
+    :param event_handler:
+        Event handler which will be called in response to file system events.
+    :param pathnames:
+        A list of pathnames to monitor.
+    :param recursive:
+        ``True`` if recursive; ``False`` otherwise.
+    """
+    for pathname in set(pathnames):
+        observer.schedule(event_handler, pathname, recursive)
+    observer.start()
+    try:
+        while True:
+            time.sleep(1)
+    except KeyboardInterrupt:
+        observer.stop()
+    observer.join()
+
+
+def schedule_tricks(observer, tricks, pathname, recursive):
+    """
+    Schedules tricks with the specified observer and for the given watch
+    path.
+
+    :param observer:
+        The observer thread into which to schedule the trick and watch.
+    :param tricks:
+        A list of tricks.
+    :param pathname:
+        A path name which should be watched.
+    :param recursive:
+        ``True`` if recursive; ``False`` otherwise.
+    """
+    for trick in tricks:
+        for name, value in list(trick.items()):
+            TrickClass = load_class(name)
+            handler = TrickClass(**value)
+            trick_pathname = getattr(handler, 'source_directory', None) or pathname
+            observer.schedule(handler, trick_pathname, recursive)
+
+
+@aliases('tricks')
+@arg('files',
+     nargs='*',
+     help='perform tricks from given file')
+@arg('--python-path',
+     default='.',
+     help='paths separated by %s to add to the python path' % os.pathsep)
+@arg('--interval',
+     '--timeout',
+     dest='timeout',
+     default=1.0,
+     help='use this as the polling interval/blocking timeout (in seconds)')
+@arg('--recursive',
+     default=True,
+     help='recursively monitor paths')
+@expects_obj
+def tricks_from(args):
+    """
+    Subcommand to execute tricks from a tricks configuration file.
+
+    :param args:
+        Command line argument options.
+    """
+    from watchdog.observers import Observer
+
+    add_to_sys_path(path_split(args.python_path))
+    observers = []
+    for tricks_file in args.files:
+        observer = Observer(timeout=args.timeout)
+
+        if not os.path.exists(tricks_file):
+            raise IOError("cannot find tricks file: %s" % tricks_file)
+
+        config = load_config(tricks_file)
+
+        try:
+            tricks = config[CONFIG_KEY_TRICKS]
+        except KeyError:
+            raise KeyError("No `%s' key specified in %s." % (
+                           CONFIG_KEY_TRICKS, tricks_file))
+
+        if CONFIG_KEY_PYTHON_PATH in config:
+            add_to_sys_path(config[CONFIG_KEY_PYTHON_PATH])
+
+        dir_path = os.path.dirname(tricks_file)
+        if not dir_path:
+            dir_path = os.path.relpath(os.getcwd())
+        schedule_tricks(observer, tricks, dir_path, args.recursive)
+        observer.start()
+        observers.append(observer)
+
+    try:
+        while True:
+            time.sleep(1)
+    except KeyboardInterrupt:
+        for o in observers:
+            o.unschedule_all()
+            o.stop()
+    for o in observers:
+        o.join()
+
+
+@aliases('generate-tricks-yaml')
+@arg('trick_paths',
+     nargs='*',
+     help='Dotted paths for all the tricks you want to generate')
+@arg('--python-path',
+     default='.',
+     help='paths separated by %s to add to the python path' % os.pathsep)
+@arg('--append-to-file',
+     default=None,
+     help='appends the generated tricks YAML to a file; \
+if not specified, prints to standard output')
+@arg('-a',
+     '--append-only',
+     dest='append_only',
+     default=False,
+     help='if --append-to-file is not specified, produces output for \
+appending instead of a complete tricks yaml file.')
+@expects_obj
+def tricks_generate_yaml(args):
+    """
+    Subcommand to generate Yaml configuration for tricks named on the command
+    line.
+
+    :param args:
+        Command line argument options.
+    """
+    python_paths = path_split(args.python_path)
+    add_to_sys_path(python_paths)
+    output = StringIO()
+
+    for trick_path in args.trick_paths:
+        TrickClass = load_class(trick_path)
+        output.write(TrickClass.generate_yaml())
+
+    content = output.getvalue()
+    output.close()
+
+    header = yaml.dump({CONFIG_KEY_PYTHON_PATH: python_paths})
+    header += "%s:\n" % CONFIG_KEY_TRICKS
+    if args.append_to_file is None:
+        # Output to standard output.
+        if not args.append_only:
+            content = header + content
+        sys.stdout.write(content)
+    else:
+        if not os.path.exists(args.append_to_file):
+            content = header + content
+        with open(args.append_to_file, 'ab') as output:
+            output.write(content)
+
+
+@arg('directories',
+     nargs='*',
+     default='.',
+     help='directories to watch.')
+@arg('-p',
+     '--pattern',
+     '--patterns',
+     dest='patterns',
+     default='*',
+     help='matches event paths with these patterns (separated by ;).')
+@arg('-i',
+     '--ignore-pattern',
+     '--ignore-patterns',
+     dest='ignore_patterns',
+     default='',
+     help='ignores event paths with these patterns (separated by ;).')
+@arg('-D',
+     '--ignore-directories',
+     dest='ignore_directories',
+     default=False,
+     help='ignores events for directories')
+@arg('-R',
+     '--recursive',
+     dest='recursive',
+     default=False,
+     help='monitors the directories recursively')
+@arg('--interval',
+     '--timeout',
+     dest='timeout',
+     default=1.0,
+     help='use this as the polling interval/blocking timeout')
+@arg('--trace',
+     default=False,
+     help='dumps complete dispatching trace')
+@arg('--debug-force-polling',
+     default=False,
+     help='[debug] forces polling')
+@arg('--debug-force-kqueue',
+     default=False,
+     help='[debug] forces BSD kqueue(2)')
+@arg('--debug-force-winapi',
+     default=False,
+     help='[debug] forces Windows API')
+@arg('--debug-force-winapi-async',
+     default=False,
+     help='[debug] forces Windows API + I/O completion')
+@arg('--debug-force-fsevents',
+     default=False,
+     help='[debug] forces Mac OS X FSEvents')
+@arg('--debug-force-inotify',
+     default=False,
+     help='[debug] forces Linux inotify(7)')
+@expects_obj
+def log(args):
+    """
+    Subcommand to log file system events to the console.
+
+    :param args:
+        Command line argument options.
+    """
+    from watchdog.utils import echo
+    from watchdog.tricks import LoggerTrick
+
+    if args.trace:
+        echo.echo_class(LoggerTrick)
+
+    patterns, ignore_patterns =\
+        parse_patterns(args.patterns, args.ignore_patterns)
+    handler = LoggerTrick(patterns=patterns,
+                          ignore_patterns=ignore_patterns,
+                          ignore_directories=args.ignore_directories)
+    if args.debug_force_polling:
+        from watchdog.observers.polling import PollingObserver as Observer
+    elif args.debug_force_kqueue:
+        from watchdog.observers.kqueue import KqueueObserver as Observer
+    elif args.debug_force_winapi_async:
+        from watchdog.observers.read_directory_changes_async import\
+            WindowsApiAsyncObserver as Observer
+    elif args.debug_force_winapi:
+        from watchdog.observers.read_directory_changes import\
+            WindowsApiObserver as Observer
+    elif args.debug_force_inotify:
+        from watchdog.observers.inotify import InotifyObserver as Observer
+    elif args.debug_force_fsevents:
+        from watchdog.observers.fsevents import FSEventsObserver as Observer
+    else:
+        # Automatically picks the most appropriate observer for the platform
+        # on which it is running.
+        from watchdog.observers import Observer
+    observer = Observer(timeout=args.timeout)
+    observe_with(observer, handler, args.directories, args.recursive)
+
+
+@arg('directories',
+     nargs='*',
+     default='.',
+     help='directories to watch')
+@arg('-c',
+     '--command',
+     dest='command',
+     default=None,
+     help='''shell command executed in response to matching events.
+These interpolation variables are available to your command string::
+
+    ${watch_src_path}    - event source path;
+    ${watch_dest_path}   - event destination path (for moved events);
+    ${watch_event_type}  - event type;
+    ${watch_object}      - ``file`` or ``directory``
+
+Note::
+    Please ensure you do not use double quotes (") to quote
+    your command string. That will force your shell to
+    interpolate before the command is processed by this
+    subcommand.
+
+Example option usage::
+
+    --command='echo "${watch_src_path}"'
+''')
+@arg('-p',
+     '--pattern',
+     '--patterns',
+     dest='patterns',
+     default='*',
+     help='matches event paths with these patterns (separated by ;).')
+@arg('-i',
+     '--ignore-pattern',
+     '--ignore-patterns',
+     dest='ignore_patterns',
+     default='',
+     help='ignores event paths with these patterns (separated by ;).')
+@arg('-D',
+     '--ignore-directories',
+     dest='ignore_directories',
+     default=False,
+     help='ignores events for directories')
+@arg('-R',
+     '--recursive',
+     dest='recursive',
+     default=False,
+     help='monitors the directories recursively')
+@arg('--interval',
+     '--timeout',
+     dest='timeout',
+     default=1.0,
+     help='use this as the polling interval/blocking timeout')
+@arg('-w', '--wait',
+     dest='wait_for_process',
+     action='store_true',
+     default=False,
+     help="wait for process to finish to avoid multiple simultaneous instances")
+@arg('-W', '--drop',
+     dest='drop_during_process',
+     action='store_true',
+     default=False,
+     help="Ignore events that occur while command is still being executed "
+          "to avoid multiple simultaneous instances")
+@arg('--debug-force-polling',
+     default=False,
+     help='[debug] forces polling')
+@expects_obj
+def shell_command(args):
+    """
+    Subcommand to execute shell commands in response to file system events.
+
+    :param args:
+        Command line argument options.
+    """
+    from watchdog.tricks import ShellCommandTrick
+
+    if not args.command:
+        args.command = None
+
+    if args.debug_force_polling:
+        from watchdog.observers.polling import PollingObserver as Observer
+    else:
+        from watchdog.observers import Observer
+
+    patterns, ignore_patterns = parse_patterns(args.patterns,
+                                               args.ignore_patterns)
+    handler = ShellCommandTrick(shell_command=args.command,
+                                patterns=patterns,
+                                ignore_patterns=ignore_patterns,
+                                ignore_directories=args.ignore_directories,
+                                wait_for_process=args.wait_for_process,
+                                drop_during_process=args.drop_during_process)
+    observer = Observer(timeout=args.timeout)
+    observe_with(observer, handler, args.directories, args.recursive)
+
+
+@arg('command',
+     help='''Long-running command to run in a subprocess.
+''')
+@arg('command_args',
+     metavar='arg',
+     nargs='*',
+     help='''Command arguments.
+
+Note: Use -- before the command arguments, otherwise watchmedo will
+try to interpret them.
+''')
+@arg('-d',
+     '--directory',
+     dest='directories',
+     metavar='directory',
+     action='append',
+     help='Directory to watch. Use another -d or --directory option '
+          'for each directory.')
+@arg('-p',
+     '--pattern',
+     '--patterns',
+     dest='patterns',
+     default='*',
+     help='matches event paths with these patterns (separated by ;).')
+@arg('-i',
+     '--ignore-pattern',
+     '--ignore-patterns',
+     dest='ignore_patterns',
+     default='',
+     help='ignores event paths with these patterns (separated by ;).')
+@arg('-D',
+     '--ignore-directories',
+     dest='ignore_directories',
+     default=False,
+     help='ignores events for directories')
+@arg('-R',
+     '--recursive',
+     dest='recursive',
+     default=False,
+     help='monitors the directories recursively')
+@arg('--interval',
+     '--timeout',
+     dest='timeout',
+     default=1.0,
+     help='use this as the polling interval/blocking timeout')
+@arg('--signal',
+     dest='signal',
+     default='SIGINT',
+     help='stop the subprocess with this signal (default SIGINT)')
+@arg('--debug-force-polling',
+     default=False,
+     help='[debug] forces polling')
+@arg('--kill-after',
+     dest='kill_after',
+     default=10.0,
+     help='when stopping, kill the subprocess after the specified timeout '
+          '(default 10)')
+@expects_obj
+def auto_restart(args):
+    """
+    Subcommand to start a long-running subprocess and restart it
+    on matched events.
+
+    :param args:
+        Command line argument options.
+    """
+
+    if args.debug_force_polling:
+        from watchdog.observers.polling import PollingObserver as Observer
+    else:
+        from watchdog.observers import Observer
+
+    from watchdog.tricks import AutoRestartTrick
+    import signal
+
+    if not args.directories:
+        args.directories = ['.']
+
+    # Allow either signal name or number.
+    if args.signal.startswith("SIG"):
+        stop_signal = getattr(signal, args.signal)
+    else:
+        stop_signal = int(args.signal)
+
+    # Handle SIGTERM in the same manner as SIGINT so that
+    # this program has a chance to stop the child process.
+    def handle_sigterm(_signum, _frame):
+        raise KeyboardInterrupt()
+
+    signal.signal(signal.SIGTERM, handle_sigterm)
+
+    patterns, ignore_patterns = parse_patterns(args.patterns,
+                                               args.ignore_patterns)
+    command = [args.command]
+    command.extend(args.command_args)
+    handler = AutoRestartTrick(command=command,
+                               patterns=patterns,
+                               ignore_patterns=ignore_patterns,
+                               ignore_directories=args.ignore_directories,
+                               stop_signal=stop_signal,
+                               kill_after=args.kill_after)
+    handler.start()
+    observer = Observer(timeout=args.timeout)
+    observe_with(observer, handler, args.directories, args.recursive)
+    handler.stop()
+
+
+epilog = """Copyright 2011 Yesudeep Mangalapilly <yesudeep@gmail.com>.
+Copyright 2012 Google, Inc.
+
+Licensed under the terms of the Apache license, version 2.0. Please see
+LICENSE in the source code for more information."""
+
+parser = ArghParser(epilog=epilog)
+parser.add_commands([tricks_from,
+                     tricks_generate_yaml,
+                     log,
+                     shell_command,
+                     auto_restart])
+parser.add_argument('--version',
+                    action='version',
+                    version='%(prog)s ' + VERSION_STRING)
+
+
+def main():
+    """Entry-point function."""
+    parser.dispatch()
+
+
+if __name__ == '__main__':
+    main()