From: Junio C Hamano <gitster@pobox.com>
Date: Sun, 10 Aug 2008 22:37:55 GMT
Subject: Re: [PATCH] git-submodule - Add 'foreach' subcommand
Message-ID: <7vsktczebg.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <1218386647-2348-1-git-send-email-mlevedahl@gmail.com>

Mark Levedahl <mlevedahl@gmail.com> writes:

> This utility is inspired by a number of threads on the mailing list
> looking for ways to better integrate submodules in a tree and work
> with them as a unit.

Thanks for keeping the topic going

> +foreach::
> +	Executes an arbitrary list of commands in each checked out submodule.
> +	$path is the name of the submodule directory relative to the
> +	superproject, and $sha1 is the commit as recorded in the superproject.
> +	And submodules defined in the superproject but not checked out are
> +	ignored by this command, and an empty command-list provides no output.
> ++
> +As an example, "git submodule foreach 'echo $path `git rev-parse HEAD`' will
> +show the path and currently checked out commit for each submodule.

I think this is a sensible building block to have.

> +cmd_foreach()
> +{
> +	git ls-files --stage | grep '^160000 ' |
> +	while read mode sha1 stage path
> +	do
> +		if test -e "$path"/.git
> +		then
> +			(cd "$path" && eval "$@")
> +		fi
> +	done
> +}

I suspect we may want to stop the loop upon failure from eval (any user
that wants to run command in all submodules no matter what could add '||:'
to the cmd list), but other than that this is a simple enough and good
addition.