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.
I don't think it makes sense to complete --legend=yes. It is the default, and
it would be only used very rarely (and then it is easy enough to just remove
the '=no' part from the suggested string).
--no-legend is replaced by --legend=no.
--quiet now implies --legend=no, but --legend=yes may be used to override that.
--quiet controls hints and warnings and such, and --legend controls just the
legends. I think it makes sense to allow both to controlled independently, in
particular --quiet --legend makes sense when using systemctl in a script to
provide some user-visible output.
Fixes#18560.
We were passing a reference to 'int arg_seal' to config_parse_bool(),
which expects a 'bool *'. Luckily, this would work, because 'bool'
is smaller than 'int', so config_parse_bool() would set the least-significant
byte of arg_seal. At least I think so. But let's use consistent types ;)
Also, modernize style a bit and don't use integers in boolean context.
This nicely covers the case when optarg is optional. The same parser can be
used when the option string passed to getopt_long() requires a parameter and
when it doesn't.
The error messages are made consistent.
Also fixes a log error c&p in --crash-reboot message.
