This is useful for a couple of cases, I'm mostly interested in case #1:
1. Verifying "reasonable" values in a trivially scriptable way
2. Debugging unexpected time span parsing directly
Test Plan:
```
% build/systemd-analyze timespan 20
Original: 20
μs: 20
Human: 20us
% build/systemd-analyze timespan 20ms
Original: 20ms
μs: 20000
Human: 20ms
% build/systemd-analyze timespan 20z
Failed to parse time span '20z': Invalid argument
```
Docbook styles required those to be present, even though the templates that we
use did not show those names anywhere. But something changed semi-recently (I
would suspect docbook templates, but there was only a minor version bump in
recent years, and the changelog does not suggest anything related), and builds
now work without those entries. Let's drop this dead weight.
Tested with F26-F29, debian unstable.
$ perl -i -0pe 's/\s*<authorgroup>.*<.authorgroup>//gms' man/*xml
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
This little new command can parse, validate, normalize calendar events,
and calculate when they will elapse next. This should be useful for
anyone writing calendar events and who'd like to validate the expression
before running them as timer units.
"*-*~1" => The last day of every month
"*-02~3..5" => The third, fourth, and fifth last days in February
"Mon 05~07/1" => The last Monday in May
Resolves#3861
This patch improves parsing and generation of timestamps and calendar
specifications in two ways:
- The week day is now always printed in the abbreviated English form, instead
of the locale's setting. This makes sure we can always parse the week day
again, even if the locale is changed. Given that we don't follow locale
settings for printing timestamps in any other way either (for example, we
always use 24h syntax in order to make uniform parsing possible), it only
makes sense to also stick to a generic, non-localized form for the timestamp,
too.
- When parsing a timestamp, the local timezone (in its DST or non-DST name)
may be specified, in addition to "UTC". Other timezones are still not
supported however (not because we wouldn't want to, but mostly because libc
offers no nice API for that). In itself this brings no new features, however
it ensures that any locally formatted timestamp's timezone is also parsable
again.
These two changes ensure that the output of format_timestamp() may always be
passed to parse_timestamp() and results in the original input. The related
flavours for usec/UTC also work accordingly. Calendar specifications are
extended in a similar way.
The man page is updated accordingly, in particular this removes the claim that
timestamps systemd prints wouldn't be parsable by systemd. They are now.
The man page previously showed invalid timestamps as examples. This has been
removed, as the man page shouldn't be a unit test, where such negative examples
would be useful. The man page also no longer mentions the names of internal
functions, such as format_timestamp_us() or UNIX error codes such as EINVAL.
nginx defines an uppercase "M" that way (in contrast to the lowercase
"m" for "minute"), and it sounds like an OK logic to follow, so that we
understand a true superset of time values nginx understands.
http://nginx.org/en/docs/syntax.html
