Re: the GPG_TTY line in bashrc produces error message in chroot environment

On Sun, 2025-10-19 at 16:39 +0800, Zhang Wen wrote:
> Xi Ruoyao <[email protected]> 于2025年10月18日周六 19:00写道：
> > 
> > On Sat, 2025-10-18 at 12:17 +0800, Zhang Wen wrote:
> > > The root cause is while the tty command returns non-zero in the chroot
> > > environment, the 'tty -s' command returns a zero value.
> > > I changed 'tty -s' to 'tty > /dev/null 2>&1' and the error message
> > > disappeared, not sure if there's a better solution.
> > 
> > I'd say it's a coreutils bug and it should be reported to the coreutils
> > developers.  "tty -s" should have the same exit status as "tty".
> > 
> > --
> > Xi Ruoyao <[email protected]>
> > --
> > http://lists.linuxfromscratch.org/sympa/info/blfs-dev
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> 
> It's not necessarily the truth, there's a code structure overview link
> below the the git line on https://www.gnu.org/software/coreutils:
> https://www.maizure.org/projects/decoded-gnu-coreutils/tty.html
> It says that the silent mode of tty only return result of the isatty
> function in the c library, while the normal mode return result of the
> ttyname one.

It's not relevant.  The info page says:

‘-s’
‘--silent’
‘--quiet’
     Print nothing; only return an exit status.

   Exit status:

     0 if standard input is a terminal
     1 if standard input is a non-terminal file
     2 if given incorrect arguments
     3 if a write error occurs
     4 if the terminal's name cannot be determined

It's not related to how the code is structured.  It's simply the code
isn't doing what the document says.  If this wasn't a bug, it would mean
"the terminal's name can be determined with -s, but it cannot without -
s."  That would be just ridiculous.

Either the code should be fixed to ensure the exit status consistent
with and without -s, or the documentation should be updated to document
the current behavior.  In either case we've encountered a bug here.

-- 
Xi Ruoyao <[email protected]>

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