前言
最近项目中遇到一个用于监控日志文件的Python包pyinotify，结合自己的项目经验和网上的一些资料总结一下，总的原理是利用pyinotify模块监控日志文件夹，当日志到来的情况下，触发相应的函数进行处理，处理完毕后删除日志文件的过程，下面就着重介绍下pyinotify
pyinotify
Pyinotify是一个Python模块，用来监测文件系统的变化。 Pyinotify依赖于Linux内核的功能—inotify（内核2.6.13合并）。 inotify的是一个事件驱动的通知器，其通知接口通过三个系统调用从内核空间到用户空间。pyinotify结合这些系统调用，并提供一个顶级的抽象和一个通用的方式来处理这些功能。
- pyinotify 说百了就是通过 调用系统的inotify来实现通知的
- inotify 既可以监视文件，也可以监视目录
- Inotify 使用系统调用而非 SIGIO 来通知文件系统事件。
Inotify 可以监视的文件系统事件包括：
| Event Name | Is an Event | Description |
| IN_ACCESS | Yes | file was accessed. |
| IN_ATTRIB | Yes | metadata changed. |
| IN_CLOSE_NOWRITE | Yes | unwrittable file was closed. |
| IN_CLOSE_WRITE | Yes | writtable file was closed. |
| IN_CREATE | Yes | file/dir was created in watched directory. |
| IN_DELETE | Yes | file/dir was deleted in watched directory. |
| IN_DELETE_SELF | Yes | 自删除，即一个可执行文件在执行时删除自己 |
| IN_DONT_FOLLOW | No | don't follow a symlink (lk 2.6.15). |
| IN_IGNORED | Yes | raised on watched item removing. Probably useless for you, prefer instead IN_DELETE*. |
| IN_ISDIR | No | event occurred against directory. It is always piggybacked to an event. The Event structure automatically provide this information (via .is_dir) |
| IN_MASK_ADD | No | to update a mask without overwriting the previous value (lk 2.6.14). Useful when updating a watch. |
| IN_MODIFY | Yes | file was modified. |
| IN_MOVE_SELF | Yes | 自移动，即一个可执行文件在执行时移动自己 |
| IN_MOVED_FROM | Yes | file/dir in a watched dir was moved from X. Can trace the full move of an item when IN_MOVED_TO is available too, in this case if the moved item is itself watched, its path will be updated (see IN_MOVE_SELF). |
| IN_MOVED_TO | Yes | file/dir was moved to Y in a watched dir (see IN_MOVE_FROM). |
| IN_ONLYDIR | No | only watch the path if it is a directory (lk 2.6.15). Usable when calling .add_watch. |
| IN_OPEN | Yes | file was opened. |
| IN_Q_OVERFLOW | Yes | event queued overflowed. This event doesn't belongs to any particular watch. |
| IN_UNMOUNT | Yes | 宿主文件系统被 umount |
IN_ACCESS，即文件被访问
IN_MODIFY，文件被write
IN_ATTRIB，文件属性被修改，如chmod、chown、touch等
IN_CLOSE_WRITE，可写文件被close
IN_CLOSE_NOWRITE，不可写文件被close
IN_OPEN，文件被open
IN_MOVED_FROM，文件被移走,如mv
IN_MOVED_TO，文件被移来，如mv、cp
IN_CREATE，创建新文件
IN_DELETE，文件被删除，如rm
IN_DELETE_SELF，自删除，即一个可执行文件在执行时删除自己
IN_MOVE_SELF，自移动，即一个可执行文件在执行时移动自己
IN_UNMOUNT，宿主文件系统被umount
IN_CLOSE，文件被关闭，等同于(IN_CLOSE_WRITE | IN_CLOSE_NOWRITE)
IN_MOVE，文件被移动，等同于(IN_MOVED_FROM | IN_MOVED_TO)
pyinotify使用例子
#!/usr/bin/python
# coding:utf-8
import os
from pyinotify import WatchManager, Notifier,ProcessEvent,IN_DELETE, IN_CREATE,IN_MODIFY
class EventHandler(ProcessEvent):
"""事件处理"""
def process_IN_CREATE(self, event):
print "Create file: %s " % os.path.join(event.path,event.name)
def process_IN_DELETE(self, event):
print "Delete file: %s " % os.path.join(event.path,event.name)
def process_IN_MODIFY(self, event):
print "Modify file: %s " % os.path.join(event.path,event.name)
def FSMonitor(path='.'):
wm = WatchManager()
mask = IN_DELETE | IN_CREATE |IN_MODIFY
notifier = Notifier(wm, EventHandler())
wm.add_watch(path, mask,auto_add=True,rec=True)
print 'now starting monitor %s'%(path)
while True:
try:
notifier.process_events()
if notifier.check_events():
notifier.read_events()
except KeyboardInterrupt:
notifier.stop()
break
if __name__ == "__main__":
FSMonitor('/root/softpython/apk_url')
本文Python pyinotify日志监控系统处理日志的方法到此结束。繁华过处，总有一些人会成为回忆，也许不该沉迷于过去，花开花落，云卷云舒，淡然才是最美的风景;总有一些情会成为曾经，也许不该执着于忆念，来者珍惜，去者放下，惜缘才是最好的记取。人生无常，自当且行且珍惜。小编再次感谢大家对我们的支持！
