It is natural to expect that an option defined with OPT_BOOLEAN() could be
used in this way:
int option = -1; /* unspecified */
struct option options[] = {
OPT_BOOLEAN(0, "option", &option, "set option"),
OPT_END()
};
parse_options(ac, av, prefix, options, usage, 0);
if (option < 0)
... do the default thing ...
else if (!option)
... --no-option was given ...
else
... --option was given ...
to easily tell three cases apart:
- There is no mention of the `--option` on the command line;
- The variable is positively set with `--option`; or
- The variable is explicitly negated with `--no-option`.
Unfortunately, this is not the case. OPT_BOOLEAN() increments the variable
every time `--option` is given, and resets it to zero when `--no-option`
is given.
As a first step to remedy this, introduce a true boolean OPT_BOOL(), and
rename OPT_BOOLEAN() to OPT_COUNTUP(). To help transitioning, OPT_BOOLEAN
and OPTION_BOOLEAN are defined as deprecated synonyms to OPT_COUNTUP and
OPTION_COUNTUP respectively.
This is what db7244b (parse-options new features., 2007-11-07) from four
years ago started by marking OPTION_BOOLEAN as "INCR would have been a
better name".
Some existing users do depend on the count-up semantics; for example,
users of OPT__VERBOSE() could use it to raise the verbosity level with
repeated use of `-v` on the command line, but they probably should be
rewritten to use OPT__VERBOSITY() instead these days. I suspect that some
users of OPT__FORCE() may also use it to implement different level of
forcibleness but I didn't check.
On top of this patch, here are the remaining clean-up tasks that other
people can help:
- Look at each hit in "git grep -e OPT_BOOLEAN"; trace all uses of the
value that is set to the underlying variable, and if it can proven that
the variable is only used as a boolean, replace it with OPT_BOOL(). If
the caller does depend on the count-up semantics, replace it with
OPT_COUNTUP() instead.
- Same for OPTION_BOOLEAN; replace it with OPTION_SET_INT and arrange to
set 1 to the variable for a true boolean, and otherwise replace it with
OPTION_COUNTUP.
- Look at each hit in "git grep -e OPT__VERBOSE -e OPT__QUIET" and see if
they can be replaced with OPT__VERBOSITY().
I'll follow this message up with a separate patch as an example.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
////////////////////////////////////////////////////////////////
GIT - the stupid content tracker
////////////////////////////////////////////////////////////////
"git" can mean anything, depending on your mood.
- random three-letter combination that is pronounceable, and not
actually used by any common UNIX command. The fact that it is a
mispronunciation of "get" may or may not be relevant.
- stupid. contemptible and despicable. simple. Take your pick from the
dictionary of slang.
- "global information tracker": you're in a good mood, and it actually
works for you. Angels sing, and a light suddenly fills the room.
- "goddamn idiotic truckload of sh*t": when it breaks
Git is a fast, scalable, distributed revision control system with an
unusually rich command set that provides both high-level operations
and full access to internals.
Git is an Open Source project covered by the GNU General Public License.
It was originally written by Linus Torvalds with help of a group of
hackers around the net. It is currently maintained by Junio C Hamano.
Please read the file INSTALL for installation instructions.
See Documentation/gittutorial.txt to get started, then see
Documentation/everyday.txt for a useful minimum set of commands, and
Documentation/git-commandname.txt for documentation of each command.
If git has been correctly installed, then the tutorial can also be
read with "man gittutorial" or "git help tutorial", and the
documentation of each command with "man git-commandname" or "git help
commandname".
CVS users may also want to read Documentation/gitcvs-migration.txt
("man gitcvs-migration" or "git help cvs-migration" if git is
installed).
Many Git online resources are accessible from http://git-scm.com/
including full documentation and Git related tools.
The user discussion and development of Git take place on the Git
mailing list -- everyone is welcome to post bug reports, feature
requests, comments and patches to git@vger.kernel.org. To subscribe
to the list, send an email with just "subscribe git" in the body to
majordomo@vger.kernel.org. The mailing list archives are available at
http://marc.theaimsgroup.com/?l=git and other archival sites.
The messages titled "A note from the maintainer", "What's in
git.git (stable)" and "What's cooking in git.git (topics)" and
the discussion following them on the mailing list give a good
reference for project status, development direction and
remaining tasks.
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