Re: [PATCH v4 1/2] for-each-repo: new command used for multi-repo operations

Hi,

Lars Hjemli wrote:

[1] The 'git -a' rewrite patch shows how I think about this command -
it's just an option to the 'git' command, modifying the way any
subcommand is invoked (btw: I don't expect that patch to be applied
since 'git-all' was deemed to generic, so I'll just carry the patch in
my own tree).

As one data point, 'git all' also seems too generic to me but 'git -a'
doesn't.  Intuition can be weird.

So if I ran the world, then having commands

	git -a diff

and

	git for-each-repo git diff

do the same thing would be fine.  Of course I don't run the world. ;-)

[...]

quoted

One more thing that nobody brought up during the previous reviews is
if we want to support subset of repositories by allowing the
standard pathspec match mechanism.  For example,

        git for-each-repo -d git diff --name-only -- foo/ bar/b\*z

might be a way to ask "please find repositories match the given
pathspecs (i.e. foo/ bar/b\*z) and run the command in the ones that
are dirty".  We would need to think about how to mark the end of the
command though---we could borrow \; from find(1), even though find
is not the best example of the UI design.

In most non-git commands, "--" represents an end-of-options marker,
allowing arbitrary options afterward without having to worry about
escaping minus signs.  So in that spirit, if this weren't a git
command, I'd expect to be able to do

	for-each-repo -- git diff -- '*.c'

and have the second '--' passed verbatim to "git diff".

Unfortunately in git (imitating commands like "grep", I suppose), "--"
means "paths start here".  That means that with the git convention,
there is only one place to pass paths to a given command.

Tracing backwards: it would be really nice to be able to do

	git for-each-repo git grep -e foo -- '*.c'

or

	git -a grep -e foo -- '*.c'

For this practical reason, it seems that paths listed after the '--'
should go to the command being run.  On the other hand, if I wanted to
limit my for-each-repo run to repositories in two subdirectories of
the cwd, I'd be tempted to try

	git for-each-repo git grep -e foo -- src/ doc/

And if I wanted to limit to different file types in the repositories
under each directory, it would be tempting to use

	git for-each-repo git grep -e foo -- 'src/*.c' 'doc/*.txt'

Is there a convention that would be usable today that is roughly
forward-compatible with that?  (To throw an example out, requiring
that each pathspec passed to for-each-repo either starts with '*' or
contains no wildcards.)

Thanks,
Jonathan