What is going on here....

[Colin Watson]

On Sun, Sep 24, 2017 at 01:24:00PM +0200, Xen wrote:
> Jay Ridgley schreef op 24-09-2017 13:10:
> > On one of my systems I have started getting the following message in
> > response to various commands:
> > 
> > cdjsys at mateo:~$ ifconfig
> > -bash: /sbin/ifconfig: Input/output error
> 
> > Any ideas???
> 
> Make sure /dev/null is a special device.
> 
> And not a regular file.

That is indeed a thing that can go wrong and could cause a few kinds of
problems, but it could not cause the problem above.  (Other than obvious
permission failures, the classic weird symptom you get on glibc-based
systems when /dev/null has somehow ended up being a regular file is that
the daemon(3) library call fails, so various server processes will fail
to start up properly - but ifconfig(8) doesn't daemonise, so that's not
what's going on above.)

-- 
Colin Watson                                       [cjwatson at ubuntu.com]