Re: git log filtering

From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Feb 7, 2007, 17:12 UTC
Message-ID: <Pine.LNX.4.64.0702070856190.8424@woody.linux-foundation.org>
In-Reply-To: <68948ca0702070841m76817d9el7ce2ec69835c50e@mail.gmail.com>

On Wed, 7 Feb 2007, Don Zickus wrote:

Show 10 quoted lines

>
> I was curious to know what is the easiest way to filter info inside a
> commit message.
> 
> For example say I wanted to find out what patches Joe User has
> submitted to the git project.
> I know I can do something like ' git log |grep -B2 "^Author: Joe User"
> ' and it will output the matches and the commit id.  However, if I
> wanted to filter on something like "Signed-off-by: Joe User", then it
> is a little harder to dig for the commit id.

There are two ways:

 - "git log" can itself do a lot of filtering. Both on date, on revisions, 
   on "modifies files/directories X, Y and Z" _and_ on strings.

   See "man git-rev-list" for more (it doesn't apply to just "git log", it 
   applies to just about any revision listing, including gitk etc)

   For example,

	git log [--author=pattern] [--committer=pattern] [--grep=pattern]

   will likely do exactly what you want. You can do

	git log --grep="Signed-off-by:.*akpm"

   on the kernel archive to see which ones were signed off by Andrew.

So the above works, and catches *most* uses. But it has problems if you want to do something fancier (and I think that includes something as simple as doing a case-insensitive grep). So the other approach is:

 - The hacky way: use "git log --pretty -z", and GNU grep -z:

	git log --pretty -z |
		grep -i -z Signed-off-by:.*junkio |
		tr '\0' '\n'

   which allows you to do anything you want with grep (or other unix tools 
   that take zero-terminated output).

> Is there a better way of doing this?  Or should I accept the fact that
> git wasn't designed to filter info like this very quickly?

Git definitely was designed to do it. The "-z" option in particular is very much designed for any generic UNIX scripting, but the *easy* cases git does internally.

		Linus