threads / discuss / 22015

git tag --contains <commit> -n=1 ?

Subject: git tag --contains <commit> -n=1 ?

## tl;dr

4 messages between Dec 23, 2009 and Dec 24, 2009.

replies: 3people: 3as markdown or json

NODA, Kai· Dec 23, 2009, 16:19 UTC · lore

Hi, I'm thinking how to find the oldest tag containing a specified commit. Eg. $ cd /usr/src/linux-linus/Documentation $ for i in *.txt; do for> echo $i for> hash=`git log -1 --format=format:%H -- $i` for> git tag --contains $hash -l 'v2.6.[0-9][0-9]'|head -1 for> done DMA-API.txt v2.6.31 DMA-ISA-LPC.txt v2.6.20 DMA-attributes.txt v2.6.27 ...

Here I wonder whether "head -1" is generally correct or not when I want the oldest tag. Moreover, as "git tag --contains ..." takes considerable time, I will be happy if I can set the maximum number in searching tags containing a commit. Or are there already some (better) ways to achieve this?

Any advice is welcome.

Thanks, Kai

Andreas Schwab· Dec 23, 2009, 17:19 UTC · re: NODA, Kai · lore

Re: git tag --contains <commit> -n=1 ?

"NODA, Kai" <nodakai@gmail.com> writes:

> Here I wonder whether "head -1" is generally correct or not when I want
> the oldest tag.

Since the output of git tag is sorted by name, generally not.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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NODA, Kai· Dec 23, 2009, 20:37 UTC · re: Andreas Schwab · lore

Re: git tag --contains <commit> -n=1 ?

Thank you for your reply, Andreas

Andreas Schwab wrote: ...

>> Here I wonder whether "head -1" is generally correct or not when I want
>> the oldest tag.
> 
> Since the output of git tag is sorted by name, generally not.

Wow, I didn't know that. But then, under the assumption that tags have names like verNNN, that behavior ensures me that "head -1" works as intended.

Maybe I look at its implementation ( refs.c:do_for_each_ref , right?) but this seems a tough code to comprehend, especially around packed/loose/extra ...

Thanks, Kai

Jeff King· Dec 24, 2009, 05:52 UTC · re: NODA, Kai · lore

Re: git tag --contains <commit> -n=1 ?

On Thu, Dec 24, 2009 at 05:37:35AM +0900, NODA, Kai wrote:

Show 5 quoted lines

> >Since the output of git tag is sorted by name, generally not.
> 
> Wow, I didn't know that.
> But then, under the assumption that tags have names like verNNN,
> that behavior ensures me that "head -1" works as intended.

If that assumption does not hold, you can also sort by date. See:

  http://article.gmane.org/gmane.comp.version-control.git/133586

-Peff