The idea is that we have strvs like list of server names or addresses, where
the majority of strings is rather short, but some are long and there can
potentially be many strings. So formattting them either all on one line or all
in separate lines leads to output that is either hard to read or uses way too
many rows. We want to wrap them, but relying on the pager to do the wrapping is
not nice. Normal text has a lot of redundancy, so when the pager wraps a line
in the middle of a word the read can understand what is going on without any
trouble. But for a high-density zero-redundancy text like an IP address it is
much nicer to wrap between words. This also makes c&p easier.
This adds a variant of TABLE_STRV which is wrapped on output (with line breaks
inserted between different strv entries).
The change table_print() is quite ugly. A second pass is added to re-calculate
column widths. Since column size is now "soft", i.e. it can adjust based on
available columns, we need to two passes:
- first we figure out how much space we want
- in the second pass we figure out what the actual wrapped columns
widths will be.
To avoid unnessary work, the second pass is only done when we actually have
wrappable fields.
A test is added in test-format-table.
The status string is modeled after our --version output: +enabled -disabled equals=more-info
For example:
Protocols: -DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=allow-downgrade/supported
We would print the whole string as a single super-long line. Let's nicely
break the text into lines that fit on the screen.
$ COLUMNS=70 build/resolvectl --no-pager nta
Global: home local intranet 23.172.in-addr.arpa lan
18.172.in-addr.arpa 16.172.in-addr.arpa 19.172.in-addr.arpa
25.172.in-addr.arpa 21.172.in-addr.arpa d.f.ip6.arpa
20.172.in-addr.arpa 30.172.in-addr.arpa 17.172.in-addr.arpa
internal 168.192.in-addr.arpa 28.172.in-addr.arpa
22.172.in-addr.arpa 24.172.in-addr.arpa 26.172.in-addr.arpa
corp 10.in-addr.arpa private 29.172.in-addr.arpa test
27.172.in-addr.arpa 31.172.in-addr.arpa
Link 2 (hub0):
Link 4 (enp0s31f6):
Link 5 (wlp4s0):
Link 7 (virbr0): adsfasdfasdfasd.com 21.172.in-addr.arpa lan j b
a.com home d.f.ip6.arpa b.com local 16.172.in-addr.arpa
19.172.in-addr.arpa 18.172.in-addr.arpa 25.172.in-addr.arpa
20.172.in-addr.arpa k i h 23.172.in-addr.arpa
168.192.in-addr.arpa d g intranet 17.172.in-addr.arpa c e.com
30.172.in-addr.arpa a f d.com e internal
Link 8 (virbr0-nic):
Link 9 (vnet0):
Link 10 (vb-rawhide):
Link 15 (wwp0s20f0u2i12):
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.
This makes the output more predictable. Also, interesting interfaces
are often the low-numbered ones (actual hardware links, not virtual
devices stacked on top), and this makes them more visible.
Those lists are very long and use up a significant chunk of screen real estate.
But the contents are mostly static (usually they just reflect built-in
configuration). Let's just not show them in 'status' output. They can still
be viewed with 'nta' verb.
This is useful to raise the log level for a single transaction or a few,
without affecting other state of the resolved as a restart would.
The log level can only be set, I didn't bother with having the ability
to restore the original as in pid1.
In subsequent commits, calls to if_nametoindex() will be replaced by a wrapper
that falls back to alternative name resolution over netlink. netlink support
requires libsystemd (for sd-netlink), and we don't want to add any functions
that require netlink in basic/. So stuff that calls if_nametoindex() for user
supplied interface names, and everything that depends on that, needs to be
moved.
We don't need a seperate output parameter that is of type int. glibc() says
that the type is "unsigned", but the kernel thinks it's "int". And the
"alternative names" interface also uses ints. So let's standarize on ints,
since it's clearly not realisitic to have interface numbers in the upper half
of unsigned int range.
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.
Similar as before: don't output ifindex twice on the same address, and
show it as comment only.
Do this for reverse lookup output and all other output too.
