Suggested by David Wilkins <dwilkins@maths.tcd.ie> in
https://bugzilla.redhat.com/show_bug.cgi?id=967521:
> [Specific boot ID is a] bit of a palaver to obtain. I consulted the
> verbose dump of the journal to discover the _BOOT_ID for the
> timestamp, and then generated the journal dump for that boot using
> journalctl _BOOT_ID=foo -o short-monotonic.
_SYSTEMD_USER_UNIT in the --user-unit flag argument should instead be
USER_UNIT. It should also have an optional `=` between the flag and the
argument.
Things like -n to specify the lines to show with systemctl and
journalctl accepts syntax like:
journalctl -n4
systemctl -n14
Previously, typing `-nXX <tab>` where XX is a number, zsh would try to
complete an integer. Now it will see the XX and use the _journalctl_none
completion. This is also how any of the single letter options that take
arguments work as well.
Some of the options in systemd can take multiple arguments, such as
systemctl's --type option. Previously, you would only be able to
complete a single type after the -t, but now zsh will continue to
complete the types, separating them by commas.
systemd-inhibit's --what command has colon (:), and that has been taken
into account.
_hosts_or_user_at_host was used by 6 different completions, and
previously was in all 6 of those files. I moved it out to its own file,
_sd_hosts_or_user_at_host. This will be autoloaded for use in other
completion functions. It also allows external completions to use this
function by simply calling _sd_hosts_or_user_at_host as in the systemd
completions.
Splitting things unnecessarily at newlines causes tab completion to take
an extremely long time. Also add a note saying that caching is not good
for journalctl's completion.
Moved zsh shell completion to shell-completion/zsh/_systemd for
automake's sake. Also allow users to specify where the files should go
with::
./configure --with-zshcompletiondir=/path/to/some/where
and by default going to `$datadir/zsh/site-functions`
