2 files changed, 67 insertions, 9 deletions

diff --git a/Lib/logging/__init__.py b/Lib/logging/__init__.py
index 615dcc7..1415226 100644
--- a/Lib/logging/__init__.py
+++ b/Lib/logging/__init__.py
@@ -41,8 +41,8 @@ except ImportError:
 
 __author__  = "Vinay Sajip <vinay_sajip@red-dove.com>"
 __status__  = "production"
-__version__ = "0.5.0.0"
-__date__    = "08 January 2007"
+__version__ = "0.5.0.1"
+__date__    = "09 January 2007"
 
 #---------------------------------------------------------------------------
 #   Miscellaneous module data
@@ -764,17 +764,15 @@ class FileHandler(StreamHandler):
         """
         Open the specified file and use it as the stream for logging.
         """
-        if codecs is None:
-            encoding = None
-        if encoding is None:
-            stream = open(filename, mode)
-        else:
-            stream = codecs.open(filename, mode, encoding)
-        StreamHandler.__init__(self, stream)
         #keep the absolute path, otherwise derived classes which use this
         #may come a cropper when the current directory changes
+        if codecs is None:
+            encoding = None
         self.baseFilename = os.path.abspath(filename)
         self.mode = mode
+        self.encoding = encoding
+        stream = self._open()
+        StreamHandler.__init__(self, stream)
 
     def close(self):
         """
@@ -784,6 +782,17 @@ class FileHandler(StreamHandler):
         self.stream.close()
         StreamHandler.close(self)
 
+    def _open(self):
+        """
+        Open the current base file with the (original) mode and encoding.
+        Return the resulting stream.
+        """
+        if self.encoding is None:
+            stream = open(self.baseFilename, self.mode)
+        else:
+            stream = codecs.open(self.baseFilename, self.mode, self.encoding)
+        return stream
+
 #---------------------------------------------------------------------------
 #   Manager classes and functions
 #---------------------------------------------------------------------------
diff --git a/Lib/logging/handlers.py b/Lib/logging/handlers.py
index 82896ad..41cbca1 100644
--- a/Lib/logging/handlers.py
+++ b/Lib/logging/handlers.py
@@ -32,6 +32,7 @@ try:
     import cPickle as pickle
 except ImportError:
     import pickle
+from stat import ST_DEV, ST_INO
 
 try:
     import codecs
@@ -286,6 +287,54 @@ class TimedRotatingFileHandler(BaseRotatingHandler):
             self.stream = open(self.baseFilename, 'w')
         self.rolloverAt = self.rolloverAt + self.interval
 
+class WatchedFileHandler(logging.FileHandler):
+    """
+    A handler for logging to a file, which watches the file
+    to see if it has changed while in use. This can happen because of
+    usage of programs such as newsyslog and logrotate which perform
+    log file rotation. This handler, intended for use under Unix,
+    watches the file to see if it has changed since the last emit.
+    (A file has changed if its device or inode have changed.)
+    If it has changed, the old file stream is closed, and the file
+    opened to get a new stream.
+
+    This handler is not appropriate for use under Windows, because
+    under Windows open files cannot be moved or renamed - logging
+    opens the files with exclusive locks - and so there is no need
+    for such a handler. Furthermore, ST_INO is not supported under
+    Windows; stat always returns zero for this value.
+
+    This handler is based on a suggestion and patch by Chad J.
+    Schroeder.
+    """
+    def __init__(self, filename, mode='a', encoding=None):
+        logging.FileHandler.__init__(self, filename, mode, encoding)
+        stat = os.stat(self.baseFilename)
+        self.dev, self.ino = stat[ST_DEV], stat[ST_INO]
+
+    def emit(self, record):
+        """
+        Emit a record.
+
+        First check if the underlying file has changed, and if it
+        has, close the old stream and reopen the file to get the
+        current stream.
+        """
+        if not os.path.exists(self.baseFilename):
+            stat = None
+            changed = 1
+        else:
+            stat = os.stat(self.baseFilename)
+            changed = (stat[ST_DEV] != self.dev) or (stat[ST_INO] != self.ino)
+        if changed:
+            self.stream.flush()
+            self.stream.close()
+            self.stream = self._open()
+            if stat is None:
+                stat = os.stat(self.baseFilename)
+            self.dev, self.ino = stat[ST_DEV], stat[ST_INO]
+        logging.FileHandler.emit(self, record)
+
 class SocketHandler(logging.Handler):
     """
     A handler class which writes logging records, in pickle format, to