getopt allows non-ambiguous abbreviations, so backwards-compat is maintained, and
people can use --kill-who (or even shorter abbreviations). English is flexible,
so in common speach people would use both forms, even if "whom" is technically
more correct. The advantage of using the longer form in the code is that we
effectively allow both forms, so we stop punishing people who DTGCT¹, but still
allow people to use the spoken form if they prefer.
1. Do the gramatically correct thing
The words and cword variables are not localized in all Bash completion
scripts that call _init_completion.
cur, prev, words, and cword (and split if using the -s flag) are all
variables that should be localized in Bash completion scripts before
calling _init_completion (even if they don't otherwise appear in the
calling script). This is done for cur and prev, but not for words and
cword. Letting words and cword remain unlocalized may clobber variables
the user is using for other purposes, which is bad.
This issue can be resolved by declaring words and cword as local
variables.
Resolves#19188.
Also, while we are at it, beef it up, by adding json-seq support (i.e.
https://tools.ietf.org/html/rfc7464). This is particularly useful in
conjunction with jq's --seq switch.
The current code is not compatible with current dkr protocols anyway,
and dkr has a different focus ("microservices") than nspawn anyway
("whole machine containers"), hence drop support for it, we cannot
reasonably keep this up to date, and it creates the impression we'd
actually care for the microservices usecase.
"machinectl list" only lists running machines while many of the MACHINES
commands use names of images; both running and non-running.
List machines from both "list" and "list-images" and use sort -u to
avoid duplicates.