inotify log file broadcaster

2013-12-08 21:41:20 -05:00
parent 0a12b0651d
commit eb94e3c6c1
9 changed files with 647 additions and 0 deletions
--- a/logApp/src/inotifyy.py
+++ b/logApp/src/inotifyy.py
@@ -0,0 +1,164 @@
+from __future__ import print_function
+
+# Pull in the IN_* macros
+from _inotifyy import *
+
+import _inotifyy
+import select, os, errno
+
+_flags = {}
+for k in dir(_inotifyy):
+    if k.startswith('IN_') and k!='IN_ALL_EVENTS':
+        _flags[k[3:]] = getattr(_inotifyy, k)
+del k
+
+def decodeMask(mask):
+    ret = []
+    for k,v in _flags.iteritems():
+        if mask&v:
+            ret.append(k)
+    return '%s %s'%(hex(mask),ret)
+
+class IToken(object):
+    def __init__(self, cb, path, inot, wd):
+        self._cb, self._inot, self._wd = cb, inot, wd
+        self.path = path
+    def __del__(self):
+        self.close()
+    def close(self):
+        if self._inot:
+            self._inot._del(self._wd)
+            self._inot = None
+    def __str__(self):
+        return 'IToken(%d,"%s")'%(self._wd, self.path)
+    __repr__=__str__
+
+class INotify(_inotifyy.INotify):
+    def __init__(self):
+        self.__done = False
+        self.__listen, self.__wake = os.pipe()
+        self.__wds = {}
+        super(INotify, self).__init__()
+
+    def close(self):
+        self.__done = True
+        os.write(self.__wake,'*')
+
+    def add(self, callback, path, mask=IN_ALL_EVENTS):
+        wd = super(INotify, self).add(path, mask)
+        try:
+            return self.__wds[wd]
+        except KeyError:
+            tok = IToken(callback, path, self, wd)
+            self.__wds[wd] = tok
+            return tok
+
+    def loop(self):
+        while not self.__done:
+            rds, _wts, _exs = select.select([self.fd, self.__listen], [], [])
+            if self.fd in rds:
+                for wd, mask, cookie, path in self.read():
+                    try:
+                        tok = self.__wds[wd]
+                    except KeyError:
+                        pass # ignore unknown wd
+                    else:
+                        tok._cb(tok, mask, cookie, path)
+            elif self.__listen in rds:
+                os.read(self.__listen,1024)
+        self.__done = False
+
+
+
+def cmdlisten(files):
+    print("Listening for",*files)
+    if len(files)==0:
+        return
+
+    def event(evt, mask, cookie, path):
+        print('Event',evt, decodeMask(mask), cookie, path)
+
+    IN = INotify()
+
+    wds = [IN.add(event, P) for P in files]
+    print(wds)
+
+    return IN
+
+class cmdtail(object):
+    def __init__(self, fname):
+        import os.path
+        self.fname = fname
+        dirname, self.fpart= os.path.split(fname)
+        self.IN = INotify()
+        self.loop = self.IN.loop
+
+        mask=IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MODIFY
+
+        self.dirwd = self.IN.add(self.direvt, dirname, mask)
+        self.fd = None
+        self.startfile()
+        self.catfile()
+
+    def startfile(self):
+        self.closefile()
+        try:
+            self.fd = open(self.fname, 'r')
+        except IOError as e:
+            if e.errno==errno.ENOENT:
+                print(self.fname, "Doesn't exist yet")
+                return
+        #self.catfile()
+
+    def closefile(self):
+        if self.fd:
+            print("Closing previous")
+            self.fd.close()
+        self.fd = None
+
+    def catfile(self):
+        if not self.fd:
+           return
+        op = self.fd.tell()
+        self.fd.seek(0, 2)
+        end = self.fd.tell()
+        if end<op:
+            print(self.fname,'got shorter...  Assuming truncation')
+            self.fd.seek(0, 0)
+        else:
+            self.fd.seek(op, 0)
+        while True:
+            D = self.fd.read(1024)
+            if D:
+                print(D)
+            else:
+                break
+
+    def direvt(self, evt, mask, cookie, path):
+        if path!=self.fpart:
+            return
+        print('Dir event',evt, decodeMask(mask), cookie, path)
+        if mask&IN_CREATE:
+            print(self.fname,'appears')
+            self.startfile()
+        if mask&IN_DELETE:
+            print(self.fname,'is deleted')
+            self.closefile()
+        if mask&IN_MOVED_FROM:
+            print(self.fname,'is renamed')
+            self.closefile()
+        if mask&IN_MODIFY:
+            print(self.fname,'is modified')
+            self.catfile()
+
+if __name__=='__main__':
+    import sys
+    if len(sys.argv)<=2:
+        print("Usage: inotifyy listen <path1> [path2] ...")
+        print("    or inotifyy tail <path>")
+        sys.exit(1)
+    elif sys.argv[1]=='listen':
+        IN = cmdlisten(sys.argv[2:])
+    elif sys.argv[1]=='tail':
+        IN = cmdtail(sys.argv[2])
+    IN.loop()