Re: Weird behavior of git rev-parse

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 14, 2009, 09:07 UTC
Message-ID: <7vvdlvhbtg.fsf@alter.siamese.dyndns.org>
In-Reply-To: <4A5C31CF.2090204@ubicom.com>

Yakup Akbay <yakbay@ubicom.com> writes:

Show 9 quoted lines

> Then I've tried
>
>    $ git rev-parse -'hi, this is a test!'
>
> the output is:
>
>    -hi, this is a test!
>
> Is this an expected behavior?

Absolutely. rev-parse was originally written as a way for Porcelain scripts to sift parameters into four different categories.

 * options and non-options (that's two)

 * args meant for rev-list and others (that's another two)

Multiplying two x two gives you four combinations.

Because you are not giving options like --revs-only, --no-revs, --flags, nor --no-flags, rev-parse outputs everything. You can try these:

$ git rev-parse --no-flags -'Hi' $ git rev-parse --no-revs HEAD $ git rev-parse --flags --no-revs -Hi HEAD

> Another questions is, usage is printed if you omit the commit id in
> git rev-list (E.g. `git rev-list -2`). Is there a reason why HEAD is
> not taken as the default?

The reason is because that is the way it has been, that is the way it is, and changing it will break existing behaviour and scripts. In other words, it is a historical accident without any deep logic.

Besides, "git rev-list" is a plumbing and didn't necessarily want a user-friendliness niceties such as "defaulting to X when nothing is given".