It turns out that units(1) is not as horrible to use in scripts
as I initially thought. When the --terse flag is combined
with an appropriate output format (set via --output-format),
units(1) is actually capable of producing very nice results.
For example:
units -o %0.f -t '4 gigabytes' bytes
is is just going to print out the expected value of 4294967296.
There is no time to waste. People have to know about it.
I am adding an example for this at the top of the examples section
because this is what users are most likely looking for.
Approved by: bcr (mentor)
Differential Revision: https://reviews.freebsd.org/D24096
Changes to units.1:
- Change the description to a more descriptive "conversion calculator".
- Sort options.
- Split the description into sections to make it easier to navigate the
manual page.
- Improve the description of various options.
- Document the default value of the output format.
- Use more mdoc macros for better readability.
- Document the behavior of the PATH environmental variable.
- Improve examples.
- Add sections: EXIT STATUS, DIAGNOSTICS, and HISTORY.
- Document that units(1) cannot convert negative values and it handles long
unit lists poorly.
- Update the documentation of the -V flag to match the implementation.
units(1) prints its version and the units data file instead of its
version and usage information.
Changes to units.c:
- Update usage information.
- Sort longopts elements.
This commit does not attempts to change the current behavior of units(1).
What's left to do is probably defining a better versioning (at the moment
units(1) always reports "FreeBSD units" as its version) and changing the
behavior of the -V flag to only print version.
Reviewed by: allanjude (earlier version), bcr
Approved by: bcr (mentor)
Differential Revision: https://reviews.freebsd.org/D18977
- notionally support a 'history file' flag. This doesn't do much now,
but is there to prevent scripts written against GNU units from
breaking
- correctly gracefully quit rather than exit (this will make it easier
to support a history file in the future)
- remove the "t" flag from fopen which was there to support windows. We
have not supported windows since at the latest, the introduction of
capsicum.
For increased compatibility with GNU units: support a -v option which
produces more verbose output when spitting out the answer.
GNU -v does additional work in the version, information, and check output which
we do not (yet?) replicate.
The units program is likely little used. It is even less likely that a script
will want the units program to print out its version number by passing -v.
GNU units uses -V for version and -v for verbosity.
Increase compatibility between these two versions (written by the same author)
by switching our flag as well.
Take this opportunity to remove bogus information about the version number and
just call it 'FreeBSD units'.
Discussed with: cperciva, rwatson
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
