Re: [PATCH v6 2/3] Documentation: alias: add notes on shell expansion

From: Ian Wienand <iwienand@redhat.com>
Date: May 27, 2024, 00:22 UTC
Message-ID: <ZlPSKfzHejm-Z5Pn@fedora19.localdomain>
In-Reply-To: <xmqqa5kcduis.fsf@gitster.g>

On Sun, May 26, 2024 at 04:26:51PM -0700, Junio C Hamano wrote:

> As I keep saying over multiple iterations, the above three bullet
> points stress too much on the minute implementation detail while
> failing to tell readers that the end-user alias receives the rest of
> the command line as arguments.

OK, I can agree that perhaps I've been a bit to fixated on the addition of "$@" and the mechanics of this. I will propose again with this trimmed. What I didn't have to help me at the time was the full command in GIT_TRACE, which I think is probably a more appropriate way to communicate these details of what's actually hitting the exec calls.

> Of course the simplest one-liner, if you had the "one" script
> already stored in the file, is to say

So the reason I fell into this, and I wonder how much this plays out for others too, is that shipping these workflow bits as stand-alone scripts would mean no !shell tricks required, it's all very logical and I would never have looked at any of this :) However, when all you have is a hammer ... since a git config .inc file was needed for other things, it has been overloaded into essentially being mini package-manger that avoids having to install additional dependencies; one-liner shell script at a time :)

> You can do one of two easy things.
> 
>     $ sh -c 'echo "$1" | grep "$2"' -      1 2

Ok, I think "sh -c" in ! aliases is a bit confusing, personally. You end up two shells nested deep, and you really have to explain what's going on with $0; it's very easy to miss.

>     $ e(){ echo "$1" | grep "$2"; };e      1 2

This method, which is used elsewhere in the docs as well, I think makes the most sense. So I've left that in as the example.

-i