Bug report

Bug description:

With patche9b4ec6 (which was a fix to issues#105623 and#105887) the test for whether or not the logfile is a file comes too late for fifos.

When the rotation check in shouldRollover() happens it does a self.stream.tell() which fails if the stream is a fifo.

Since doing a filetype check on NFS is expensive (as per those bugs) I'd like to suggest either:

try:pos=self.stream.tell()exceptio.UnsupportedOperation:# It's a FIFO or other non-seekable streampos=None

or

pos=self.stream.tell()ifself.stream.seekable()elseNone

Alas, I'm not using NFS anywhere so can't quite test which would still be performant here.

I also haven't checked if this kind of fix should be done elsewhere but if the fix is fine I'm happy to put in the effort and see what I can spot. :)

CPython versions tested on:

3.13

Operating systems tested on:

Linux

Linked PRs

• gh-143237: Fix support of named pipes in the rotating logging handlers #143259
• [3.14] gh-143237: Fix support of named pipes in the rotating logging handlers (GH-143259) #143297
• [3.13] gh-143237: Fix support of named pipes in the rotating logging handlers (GH-143259) #143298