The verb works only on running service units, so complete on that as the first
parameter, and a local file as the second. The other parameters are inside the
service namespace so we can't autocomplete from the outside, return early.
bootctl is rather useful to have, even if on a system without UEFI,
as it has a number of verbs that are unrelated to UEFI (e.g kernel-identify),
and more importantly, it supports --root to operate on directory trees
(which could be intended to be deployed on UEFI) so let's make sure we
always build it.
I'm not quite sure what the original intent of this line was, but it
doesn't work in the one call-site the "required" argument is actually
used. The "writable" flag was indexed as a scalar leaving only the
"e" to compare against.
Instead, let's just sort the parsed flags and compare the whole thing.
Also substitute "required" as a pattern, so that pattern based
comparisons may be supported.
The systemctl completion previously made use of PREFIX as a pattern
argument to list-unit-files and list-units. This had the problem of
erroneously filtering the results that were stored in the cache, and
erroneously filtering results that might have been requested according
to the users configuration (e.g. _correct completer, certain
matcher-lists or tag-orders, etc.).
Unfortunately, the runtime of list-unit-files increases when no pattern
argument is provided, and systemctl show, used to filter those units,
can become unacceptably slow when provided with too many units to
describe.
Let's re-introduce the pattern argument to list-unit-files and
list-units where necessary in order to alleviate these bottlenecks
without poisining the cache. A 'use-pattern' style is introduced that
may be used to disable this behavior if it is undesired. We can still
expect that certain completions, like `systemctl start <TAB>` will be
slow, like before. To fix this we will need systemd to learn a more
efficient way of filtering the units than parsing systemctl show.
The systemctl invocations used for these completions match the ones used
for the _sys_really_all_units parameter, so we should really just use
the cached parameter rather than recomputing the result.
Template names can be learned from the filesystem, so there isn't a need
to parse the output of systemctl list-unit-files in this case. This
should accelerate the completion of some verbs like enable.
