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How to get wall working?

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<20190926170305.savjlhbcwhrvoy6w@wolfsden.cz>
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Hello,
could anyone here provide some tips on getting wall working? Currently
when I try it there is no error and exit code is 0

# echo foo | wall; echo $?
0

however the message does not seem to be displayed anywhere. Exact same
workflow does work in archlinux, so I assume I need to turn something on
somewhere but I have no idea what.

Thanks for help

W.

-- 
There are only two hard things in Computer Science:
cache invalidation, naming things and off-by-one errors.
Laurent Bercot <ska-devel@skarnet.org>
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<emd1ff2a03-5b55-43c3-999e-5e951028df1f@elzian>
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<20190926170305.savjlhbcwhrvoy6w@wolfsden.cz> (view parent)
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>Hello,
>could anyone here provide some tips on getting wall working? Currently
>when I try it there is no error and exit code is 0

Hi Wolf,

wall(1) depends on a libc feature named utmp, that cannot be implemented
in the libc in a secure way. For this reason, musl (the libc that Alpine
uses) does not implement utmp; instead, it provides stubs that do 
nothing.
That is why programs that use utmp - such as wall, who or w - output
nothing but still exit successfully. This is expected, a feature, and
cannot be quick-fixed.

  There is a way to implement utmp securely, but it requires running a
daemon at boot time (and utmp is only functioning correctly while the
daemon is alive). That is exactly what the utmps package (written by
yours truly) does. utmps is being successfully used in Adélie Linux,
another musl-based distribution; it is a natural complement to musl
for distributions that wish to support utmp.

  So far utmps hasn't been integrated to Alpine; doing so requires a
few additional core dependencies, and a bit of work (every package
that uses utmp needs to be rebuilt and linked against utmps). However,
if there's interest from the Alpine maintainers, I'll be glad to
help them set this up.

--
  Laurent
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