This time, various commands with non-trivial requirements are handled.
So the series is shorter, but has a pattern of feature additions and
then those new features being used. The way that --help output is
formatted is changed a bit in various places. Those changes are
described in individual commits.
22 'static int help()' functions left after this.
Almost all programs are simple and have only a single command. When
printing options, let's just use the first COMMAND block found by default.
This means we can drop the explicit program-name argument and reduce
copy&paste boilerplate.
The custom help() is replaced by a COMMAND() description, and
--introspect-cli is added. An explicit "Commands" option group is added
so that the section heading stays the same. The abstract is changed to the
imperative. --help now goes through the pager, like other commands with
--no-pager.
I am really not a fan of full code lines passed to macros as parameters.
Let's get rid of the 3rd parameter of FOREACH_OPTION() hence:
1. Let's return errors just as a regular value (though a negative one),
that can be handled via a OPTION_ERROR case statement for the switch.
This normalizes handling of the error, just like any other event
returned by the option parser.
2. In order to avoid exploding the amount of boilerplate in each use
(that just propagates the error on OPTION_ERROR), let's then
introduce an explicit FOREACH_OPTION_OR_RETURN(), that returns from
the calling function on its own (and makes that clear in the name).
Together this cleans up, normalizes the logic and shortens the code.
It was requested to make the 'c', 'opt', and 'arg' params the same, i.e.
defined through the FOREACH_OPTION macro. But we can't do that easily,
because 'c' was defined in the for loop definition, and we can only
define variables of the same type in that way. Also, in some cases we
need only 'c', in other cases with need 'c' and 'arg, in some cases 'c'
and 'opt', and in other cases all three. We'd need to either
conditionalize or mark those variables with _unused_ to deal with
compiler warnings. But a different approach works quite nicely: add
state.opt and state.arg to show the current option and it's argument.
(The short names are picked on purpose to reduce verbosity since those
are used a lot.)
This commit cleans up the includes for all the small tools across
the tree.
A few cases of returning EXIT_SUCCESS are replaced with returning
0 to avoid including <stdlib.h>.
Split out of #37344.
When looking at configuration, often a user wants to suppress the comments and
just look at the parts that actually configure something, roughly equivalent to
systemd-analyze cat-config … | rg -v '^(#|;|$)
This switch implements this natively, skipping lines that start with a comment
character or only contain whitespace.
For formats that have section headers, section headers are skipped, if only
followed by stuff that would be skipped. (The last section header is printed
when we're about to print some actual output.)
Note that the caller doesn't know if the format has headers or not. We do format
type detection in pretty-print.c. So the caller only specifies tldr=true|false, and
conf_files_cat() figures out if the format has headers and whether those should
be handled specially.
The comments that show the file name are always printed, even if all of the file
is suppressed.
This is a partial answer to the discussions in
https://github.com/systemd/systemd/pull/28919,
https://github.com/systemd/systemd/pull/29248. If the default config is shown in
config files, the user can conveniently use '--tldr' to show the relevant parts.
The name "def.h" originates from before the rule of "no needless abbreviations"
was established. Let's rename the file to clarify that it contains a collection
of various semi-related constants.
systemd-sysctl currently fails silently under any of these conditions:
- Missing permission to write a sysctl.
- Invalid sysctl (path doesn't exists).
- Ignore failure flag ('-' in front of the sysctl name).
Because of this behaviour, configuration issues can go unnoticed as
there is no way to detect those unless going through the logs.
--strict option forces systemd-sysctl to fail if a sysctl is invalid or
if permission are insufficient. Errors on sysctl marked as "ignore
failure" will still be ignored.
Increase the log severity in case of writing to a non existent sysctl
parameter as this can either be caused by a misspelling or a kernel mis-
configuration, e.g. in case YAMA does not get loaded due to a incomplete
lsm= override:
systemd-sysctl[354]: Couldn't write '1' to 'kernel/yama/ptrace_scope', ignoring: No such file or directory
In general we almost never hit those asserts in production code, so users see
them very rarely, if ever. But either way, we just need something that users
can pass to the developers.
We have quite a few of those asserts, and some have fairly nice messages, but
many are like "WTF?" or "???" or "unexpected something". The error that is
printed includes the file location, and function name. In almost all functions
there's at most one assert, so the function name alone is enough to identify
the failure for a developer. So we don't get much extra from the message, and
we might just as well drop them.
Dropping them makes our code a tiny bit smaller, and most importantly, improves
development experience by making it easy to insert such an assert in the code
without thinking how to phrase the argument.
Our own config generates logs like this:
systemd-sysctl[1280]: Not setting net/ipv4/conf/all/rp_filter (explicit setting exists).
systemd-sysctl[1280]: Not setting net/ipv4/conf/default/rp_filter (explicit setting exists).
systemd-sysctl[1280]: Not setting net/ipv4/conf/all/accept_source_route (explicit setting exists).
systemd-sysctl[1280]: Not setting net/ipv4/conf/default/accept_source_route (explicit setting exists).
systemd-sysctl[1280]: Not setting net/ipv4/conf/all/promote_secondaries (explicit setting exists).
systemd-sysctl[1280]: Not setting net/ipv4/conf/default/promote_secondaries (explicit setting exists).
There is no error and nothing really to see.