openssh unix dev - Feb 2021 - [openssh-commits] [openssh] 02/02: upstream: hostname is not specified by POSIX but uname -n is, so use

On Sun, Feb 07, 2021 at 03:43:24PM -0700, Bob Proulx
wrote:
> Tim Rice wrote:
> > > -HOST=`hostname | cut -f1 -d.`
> > > -HOSTNAME=`hostname`
> > > +HOST=`uname -n | cut -f1 -d.`
> > > +HOSTNAME=`uname -n`
> > 
> > This may not work as intended.
> > ....
> > tim at server01-UnixWare 69% hostname
> > server01.int.multitalents.net
> > tim at server01-UnixWare 70% uname -n
> > server01
> > ....
> 
> I'll just note that on Debian, Ubuntu, other derivatives (such as
> Mint, Trisquel...) both the "uname -n" and "hostname"
values would
> typically be just the short name.  It's not just UnixWare...
> 
>     rwp at havoc:~$ uname -n
>     havoc
> 
>     rwp at havoc:~$ hostname
>     havoc
> 
Isn't it just 'hostname -f'?

    chris$ hostname -f
    t470.zbmc.eu
    chris$ hostname
    t470


-- 
Chris Green

Chris Green wrote:
> Isn't it just 'hostname -f'?
> 
>     chris$ hostname -f
>     t470.zbmc.eu
>     chris$ hostname
>     t470
The hostname -f option is a "new-ish" Linux specific option.  It's
not
portable.  And because it works by doing a reverse DNS lookup it
depends upon live network connectivity at that moment working for the
network lookup and the results are spotty depending upon how DNS is
set up and how many IP addresses are configured on the host.

It's problematic.

Bob