From: Phillip Wood <phillip.wood123@gmail.com>
Date: Sun, 14 Sep 2025 13:48:45 GMT
Subject: Re: [QUESTION] mergetool environment variables
Message-ID: <a57d5857-b096-4d92-993a-3f09d15cdcb9@gmail.com>
In-Reply-To: <004101dc250d$18173950$4845abf0$@nexbridge.com>

Hi Randall

On 14/09/2025 01:18, rsbecker@nexbridge.com wrote:
> On September 13, 2025 5:04 PM, Johannes Sixt wrote:
>> To: rsbecker@nexbridge.com
>> Cc: git@vger.kernel.org
>> Subject: Re: [QUESTION] mergetool environment variables
>>
>> Am 13.09.25 um 16:42 schrieb rsbecker@nexbridge.com:
>>> Let me try to infer what is happening and please correct me if my
>>> assumptions are wrong:
>> I'm sorry to say that I can't help. I tried to disentangle what is going on, but this
>> stuff is far too convoluted to be understood in a few minutes. I cannot tell if it is
>> possible to write a mergetool that is not installed with Git.
>>
>> I would just copy one of the existing tool scripts and run `make install` from the Git
>> source directory.
> 
> Yes, it needs to be in the git install area. Adding export BASE export LOCAL, etc.,
> works to resolve the situation. I wonder whether that should be documented.

Looking at t7610-mergetool.sh I think you can use mergetool.<tool>.cmd 
to call a user defined merge tool. The value of the config variable is 
eval'd in the shell so if you run

     git config mergetool.my-tool.cmd 'my-tool "$BASE" "$LOCAL" "$REMOTE"'

then

     git mergetool --tool=my-tool

will run

     my-tool <base-file> <local-file> <remote-file>

on each unmerged file

Thanks

Phillip