Re: is hard-coding the group name, "tty", portable enough for who -a?

[Jim Meyering]

Andreas Schwab <address@hidden> wrote:
> Jim Meyering <address@hidden> writes:
>> It's starting to look like the cost/benefit ratio is too high,
>> so I don't expect to spend time on this.
>> However, if someone can propose a portable and reliable test
>> for that attribute, I'll be happy to consider it.
>
> How about adding a configure option to set the expected group?  The
> default could just be "tty" since it's the right one for the vast
> majority of systems, but allows to override it if necessary.

That would work on systems with a designated TTY group name.
What about those older SYSV-derived systems where stat --format %G $(tty)
prints the primary group of the user running who?
I don't know enough about how write/who/mesg work on
those systems (maybe write is set-*U*ID, not set-GID?),
but patches are always welcome.