Re: [PATCH] for-each-repo: do nothing on empty config

Eric Sunshine [off-list ref] writes:

Is the behavior implemented by this patch desirable? That is, if the
user mistypes the name of the configuration variable, would it be
better to let the user know about the problem by returning an error
code rather than succeeding silently? Or do you foresee people
intentionally running the command against an empty config variable?
That might be legitimate in automation situations. If legitimate to
have an empty config, then would it be helpful to somehow distinguish
between an empty config variable and a non-existent one (assuming we
can even do that)?

I am guessing, without reading the mind of those who designed the
feature, that the envisioned use pattern is that a configuration
variable is designated, "git for-each-ref --config=<var> <cmd>" is
carved into stone in a script that is run periodically with the
hardcoded variable name in it, but the value of the variable may
change from time to time.  If it is expected that the variable can
sometimes be empty, then erroring out or even issuing a warning
would be counter-productive.

Is the API of this command ideal? It feels odd to force the user to
specify required input via a command-line option rather than just as a
positional argument. In other words, since the config variable name is
mandatory, an alternative invocation format would be:

    git for-each-repo <config-var> <cmd>

Or not to use any configuration variable (or not to have the
for-each-repo subcommand at all) and let the users write
something along the lines of...

	git config --get-all <config-var> |
	while read repo
	do
		( cd "$repo" && <cmd> )
	done

which is not all that bad and much more flexible.

Or do you foresee future enhancements expanding the ways in which the
repo list can be specified (such as from a file or stdin or directly
via the command-line), in which case the `--config` option makes
sense.

On Wed, Jan 6, 2021 at 3:50 PM Junio C Hamano [off-list ref] wrote:

Eric Sunshine [off-list ref] writes:

quoted

Is the API of this command ideal? It feels odd to force the user to
specify required input via a command-line option rather than just as a
positional argument. In other words, since the config variable name is
mandatory, an alternative invocation format would be:

    git for-each-repo <config-var> <cmd>

Or not to use any configuration variable (or not to have the
for-each-repo subcommand at all) and let the users write
something along the lines of...

        git config --get-all <config-var> |
        while read repo
        do
                ( cd "$repo" && <cmd> )
        done

which is not all that bad and much more flexible.

I had the same thought/question about why git-for-each-repo exists,
though I didn't verbalize it since I assumed the reason was covered
during the original discussion or patch submission, which I did not
follow. I can see this command possibly being useful for Windows users
who don't necessarily have a Unix-like shell or MS PowerShell with
which to open-code the loop you illustrated. This may be especially
important when this is used for some sort of scheduled maintenance on
Windows, as a guess.