Like it's customary in our codebase bus_error_message() internally takes
abs() of the passed error anyway, hence no need to explicitly negate it.
We mostly got this right, but in too many cases we didn't. Fix that.
Instead of reading these files at startup and never again, let's read
them when we need them. As an optimization (in particular as some of
these files contain the data for many fields at once) let's cache the
results as long as the stat data (i.e. mtime) remains stable.
Also, while we are at it, if we can't read any of these props, let's not
fail everything, but continue without the data.
Presently, CLI utilities such as systemctl will check whether they have a tty
attached or not to decide whether to parse /proc/cmdline or EFI variable
SystemdOptions looking for systemd.log_* entries.
But this check will be misleading if these tools are being launched by a
daemon, such as a monitoring daemon or automation service that runs in
background.
Make log handling of CLI tools uniform by never checking /proc/cmdline or EFI
variables to determine the logging level.
Furthermore, introduce a new log_setup_cli() shortcut to set up common options
used by most command-line utilities.
There's no point in caching this. Let's always get this directly from
sysfs, so that we can never get out-of-date data here (after all this is
going to be cheap, and people might overmount it or so)
Let's not cache the uname(), it's very cheap to get it, and just means
we might get out of sync with what is current. After all, the data might
change IRL, due to setarch and stuff.
It's not that I think that "hostname" is vastly superior to "host name". Quite
the opposite — the difference is small, and in some context the two-word version
does fit better. But in the tree, there are ~200 occurrences of the first, and
>1600 of the other, and consistent spelling is more important than any particular
spelling choice.
This cleans up and unifies the outut of --help texts a bit:
1. Highlight the human friendly description string, not the command
line via ANSI sequences. Previously both this description string and
the brief command line summary was marked with the same ANSI
highlight sequence, but given we auto-page to less and less does not
honour multi-line highlights only the command line summary was
affectively highlighted. Rationale: for highlighting the description
instead of the command line: the command line summary is relatively
boring, and mostly the same for out tools, the description on the
other hand is pregnant, important and captions the whole thing and
hence deserves highlighting.
2. Always suffix "Options" with ":" in the help text
3. Rename "Flags" → "Options" in one case
4. Move commands to the top in a few cases
5. add coloring to many more help pages
6. Unify on COMMAND instead of {COMMAND} in the command line summary.
Some tools did it one way, others the other way. I am not sure what
precisely {} is supposed to mean, that uppercasing doesn't, hence
let's simplify and stick to the {}-less syntax
And minor other tweaks.
For executables which take a verb, we should list the verbs first, and
then options which modify those verbs second. The general layout of
the man page is from general description to specific details, usually
Overview, Commands, Options, Return Value, Examples, References.
When emitting the calendarspec warning we want to see some color.
Follow-up for 04220fda5c.
Exceptions:
- systemctl, because it has a lot hand-crafted coloring
- tmpfiles, sysusers, stdio-bridge, etc, because they are also used in
services and I'm not sure if this wouldn't mess up something.
This way, we can extend the macro a bit with stuff pulled in from other
headers without this affecting everything which pulls in macro.h, which
is one of our most basic headers.
This is just refactoring, no change in behaviour, in prepartion for
later changes.
Now that we don't (mis-)use the env file parser to parse kernel command
lines there's no need anymore to override the used newline character
set. Let's hence drop the argument and just "\n\r" always. This nicely
simplifies our code.
This is a bit like the info link in most of GNU's --help texts, but we
don't do info but man pages, and we make them properly clickable on
terminal supporting that, because awesome.
I think it's generally advisable to link up our (brief) --help texts and
our (more comprehensive) man pages a bit, so this should be an easy and
straight-forward way to do it.