Re: How to display "HEAD~*" in "git log"

From: Konstantin Khomoutov <kostix@bswap.ru>
Date: Jul 5, 2022, 09:25 UTC
Message-ID: <20220705092514.hsm7cou5bqvajvgq@carbon>
In-Reply-To: <17411d88-b27a-2d20-623d-85c49dc7754e@mails.ucas.ac.cn>

On Tue, Jul 05, 2022 at 03:11:49PM +0800, wuzhouhui wrote:

Show 19 quoted lines

> I frequently use "git rebase" to move commit to a specific location, to
> know which commit ID as param of "git rebase", I have to list all commits
> by "git log --oneline", then copy specific commit ID, and executing "git
> rebase" as
> 
>   git rebase -i <copied commit ID>~
> 
> because SHA sum is hard to memorize, so I have to use copy and past,
> which is too boring. So, I wonder if there is a way to let "git log"
> display commits like following:
> 
>   HEAD   <one line commit message>
>   HEAD~1 <one line commit message>
> HEAD~2 <one line commit message>
> HEAD~3 <one line commit message>
>   ...
> 
> With these "HEAD~*", I can easily directly type them and no need to
> move my fingers out of keyboard.

You can script this. Provided you have a POSIX-compatible shell (such as Bash), the encantation would read something like

 $ git log --oneline | { n=0; while read line; do printf '%d\t%s\n' $n "$line"; done; }

This is admittedly not convenient so it makes sense to turn into an alias:

 [alias]
   relog = "!relog() { git log --oneline \"$@\" | { n=0; while read line; do printf 'HEAD~%d\t%s\n' $n \"$line\"; n=$((n+1)); done; }; }; relog"

Then the call

 $ git relog

would output something like

HEAD~0 deadbeef Commit message HEAD~1 fadedfac Another commit message HEAD~2 12345678 Yet another commit message

...and so on.

It's easy to make that script not output "~0" for the very first entry and output just "~" instead of "~1" for the second, but I what's presented is enough for an example.