Browsing git commit history with fzf

gistfile1.sh

# fshow - git commit browser (enter for show, ctrl-d for diff, ` toggles sort)
fshow() {
  local out shas sha q k
  while out=$(
      git log --graph --color=always \
          --format="%C(auto)%h%d %s %C(black)%C(bold)%cr" "$@" |
      fzf --ansi --multi --no-sort --reverse --query="$q" \
          --print-query --expect=ctrl-d --toggle-sort=\`); do
    q=$(head -1 <<< "$out")
    k=$(head -2 <<< "$out" | tail -1)
    shas=$(sed '1,2d;s/^[^a-z0-9]*//;/^$/d' <<< "$out" | awk '{print $1}')
    [ -z "$shas" ] && continue
    if [ "$k" = ctrl-d ]; then
      git diff --color=always $shas | less -R
    else
      for sha in $shas; do
        git show --color=always $sha | less -R
      done
    fi
  done
}

Thanks everybody for sharing your versions. All of this was so helpful!

After spending some hours of optimizing, I'd like to throw my version on the table as well. It adds the diff stats in the preview window, using a dimmed presentation:

When entering a commit, another fzf instance opens up containing a list of files changed in that commit, with the preview window showing the diff for that file:

Entering a file shows the diff on that file with its complete context.

The git-fuzzy-diff function detects whether diff-so-fancy is installed and, if so, uses it.

Furthermore I tried to split and structure the code a bit in order to not have just one huge intransparent command. I started off from @victorbrca's version and now it looks like this:

GIT_FZF_DEFAULT_OPTS="
	$FZF_DEFAULT_OPTS
	--ansi
	--reverse
	--height=100%
	--bind shift-down:preview-down
	--bind shift-up:preview-up
	--bind pgdn:preview-page-down
	--bind pgup:preview-page-up
	--bind q:abort
	$GIT_FZF_DEFAULT_OPTS
"

git-fuzzy-diff ()
{
	PREVIEW_PAGER="less --tabs=4 -Rc"
	ENTER_PAGER=${PREVIEW_PAGER}
	if [ -x "$(command -v diff-so-fancy)" ]; then
		PREVIEW_PAGER="diff-so-fancy | ${PREVIEW_PAGER}"
		ENTER_PAGER="diff-so-fancy | sed -e '1,4d' | ${ENTER_PAGER}"
	fi

	# Don't just diff the selected file alone, get related files first using
	# '--name-status -R' in order to include moves and renames in the diff.
	# See for reference: https://stackoverflow.com/q/71268388/3018229
	PREVIEW_COMMAND='git diff --color=always '$@' -- \
		$(echo $(git diff --name-status -R '$@' | grep {}) | cut -d" " -f 2-) \
		| '$PREVIEW_PAGER

	# Show additional context compared to preview
	ENTER_COMMAND='git diff --color=always '$@' -U10000 -- \
		$(echo $(git diff --name-status -R '$@' | grep {}) | cut -d" " -f 2-) \
		| '$ENTER_PAGER

	git diff --name-only $@ | \
		fzf ${GIT_FZF_DEFAULT_OPTS} --exit-0 --preview "${PREVIEW_COMMAND}" \
		--preview-window=top:85% --bind "enter:execute:${ENTER_COMMAND}"
}

git-fuzzy-log ()
{
	PREVIEW_COMMAND='f() {
		set -- $(echo -- "$@" | grep -o "[a-f0-9]\{7\}")
		[ $# -eq 0 ] || (
			git show --no-patch --color=always $1
			echo
			git show --stat --format="" --color=always $1 |
			while read line; do
				tput dim
				echo " $line" | sed "s/\x1B\[m/\x1B\[2m/g"
				tput sgr0
			done |
			tac | sed "1 a \ " | tac
		)
	}; f {}'

	ENTER_COMMAND='(grep -o "[a-f0-9]\{7\}" | head -1 |
		xargs -I % bash -ic "git-fuzzy-diff %^1 %") <<- "FZF-EOF"
		{}
		FZF-EOF'

	git log --graph --color=always --format="%C(auto)%h %s%d " | \
		fzf ${GIT_FZF_DEFAULT_OPTS} --no-sort --tiebreak=index \
		--preview "${PREVIEW_COMMAND}" --preview-window=top:15 \
		--bind "enter:execute:${ENTER_COMMAND}"
}

In my gitconfig I have set up aliases for it:

[alias]
	fd = !bash -ic 'git-fuzzy-diff \"$@\"' x
	fl = !bash -ic 'git-fuzzy-log \"$@\"' x

Perhaps someone should turn this into a zsh plugin?

@melkster Actually there is a project called forgit, which does something similar based on fzf and is available as a zsh plugin.

@carlfriedrich Interesting, I'll check it out!

@melkster FYI I edited my post above with an updated version, adding a git-fuzzy-diff command which shows a diff for each changed file separately.

I think one could plug this into forgit, if it would allow for customizing the preview command, which is not possible at the moment. I created an issue for that. If you are interested in that as well, maybe you could add a comment there to show that I'm not the only person who might want this. :-)