holocron/plugins/git/skills/git-history/references/git-log-format.md

topic, source_keys

topic	source_keys
git-log-format	git-scm-log-docs git-scm-diff-docs

Named Format Presets (--format / --pretty)

Name	Output
oneline	<hash> <title>
short	hash, author, title
medium	hash, author, date, full message (default)
full	adds committer
fuller	separate author/committer dates
reference	<abbrev> (<title>, <date>) — for use in commit messages
email	RFC 2822 email format
raw	full object as stored in the object database
format:<str>	custom template with placeholders

Custom Format Placeholders

Commit identity:

Placeholder	Meaning
%H	full commit hash
%h	abbreviated commit hash
%T	tree hash
%t	abbreviated tree hash
%P	full parent hashes
%p	abbreviated parent hashes

Author:

Placeholder	Meaning
%an	author name
%aN	author name (mailmap-resolved)
%ae	author email
%aE	author email (mailmap-resolved)
%ad	author date (respects --date=)
%ar	author date, relative
%at	author date, UNIX timestamp
%ai	author date, ISO 8601-like
%aI	author date, strict ISO 8601
%as	author date, short (YYYY-MM-DD)

Committer:

Placeholder	Meaning
%cn	committer name
%ce	committer email
%cd	committer date (respects --date=)
%cr	committer date, relative
%ct	committer date, UNIX timestamp
%ci	committer date, ISO 8601-like
%cs	committer date, short

Message:

Placeholder	Meaning
%s	subject (first line)
%f	sanitized subject (filename-safe)
%b	body (everything after blank line following subject)
%B	raw body (subject + body)
%N	commit notes

Refs and decorations:

Placeholder	Meaning
%d	ref names (like --decorate)
%D	ref names without surrounding parentheses
%S	ref name by which commit was reached (requires --source)
%(decorate[:opts])	custom decorated refs; options: prefix=, suffix=, separator=, pointer=, tag=
%(describe[:opts])	like git describe; options: tags=, abbrev=, match=, exclude=

GPG signature:

Placeholder	Meaning
%G?	status: G=good, B=bad, U=unknown, X=expired, R=revoked, N=no signature
%GS	signer name
%GK	signing key ID

Trailers:

%(trailers[:key=<k>][,only][,separator=<s>][,unfold][,keyonly][,valueonly])

Formatting / color:

Placeholder	Meaning
%n	newline
%%	literal %
%Cred / %Cgreen / %Cblue / %Creset	terminal colors
%C(<spec>)	color per git-config spec
%<(<n>[,trunc])	right-pad field to width n
%>(<n>)	left-pad to width

Reflog (requires -g / --walk-reflogs):

Placeholder	Meaning
%gD	reflog selector (e.g. refs/stash@{1})
%gd	shortened reflog selector
%gs	reflog subject

Pickaxe Search: -S and -G

-S<string> — finds commits where the count of <string> changed (i.e. the string was added or removed net). Does not match commits where the string merely appears in a diff hunk without a count change.

rtk git log -S"my_function"
rtk git log -S"my_function" --pickaxe-regex    # treat as POSIX ERE
rtk git log -S"my_function" --pickaxe-all      # show all files in matching changesets

-G<regex> — finds commits where any added or removed line in the patch matches <regex>. Broader than -S: matches whenever the pattern appears in diff text regardless of count.

rtk git log -G"frotz\(nitfol"

Critical distinction: given a diff that removes one occurrence of foo and adds one occurrence of foo (net change = 0):

• -S"foo" — does not match (count unchanged)
• -G"foo" — matches (pattern appears in patch text)

Binary files are searched by -S; ignored by -G unless --text is supplied.

--diff-filter (full table)

Selects commits (in git log) or files (in git diff) by change type:

Letter	Meaning
A	Added
C	Copied
D	Deleted
M	Modified
R	Renamed
T	Type changed (regular file ↔ symlink ↔ submodule)
U	Unmerged (conflict)
X	Unknown (indicates a git bug)
B	Pairing broken

Lowercase letters exclude that type:

rtk git log --diff-filter=ad       # exclude added and deleted files
rtk git log --diff-filter=M        # only show commits with modified files

C and R only appear when copy/rename detection is enabled (-C, -M flags or diff.renames config).

-L — Line Range History (full syntax)

Traces the evolution of a specific range of lines or a named function through commits. Implies --patch.

Bare git, not rtk git, on every -L form below: rtk truncates each diff body line at roughly 72 characters with an ellipsis, on the one query whose whole point is showing line content.

git log -L 10,20:file.txt                          # bare per ADR-0023
git log -L /start_pattern/,/end_pattern/:file.txt  # bare per ADR-0023
git log -L :myfunction:src/app.c                   # bare per ADR-0023
git log -L /init/,+15:config.py                    # bare per ADR-0023; 15 lines after first /init/ match

Range formats:

Format	Meaning
<n>	Absolute line number (1-based)
/<regex>/	First line matching regex from previous range end
^/<regex>/	First line matching regex from file start
+<n> / -<n>	Offset relative to <start> (end position only)

Limitations: incompatible with --raw, --numstat, --shortstat, --name-only, --name-status, --check. Cannot use pathspec limiters alongside -L.

Graph and Ancestry Filters

rtk git log --first-parent            # at merges, follow only first parent (mainline evolution)
rtk git log --merges                  # only merge commits (≥2 parents); equivalent to --min-parents=2
rtk git log --no-merges               # only non-merge commits; equivalent to --max-parents=1
rtk git log --ancestry-path D..M      # only commits actually on the path from D to M
rtk git log --min-parents=<n>         # include only commits with ≥ n parents
rtk git log --max-parents=<n>         # include only commits with ≤ n parents

--ancestry-path is significant: without it, D..M includes all commits reachable from M but not D — including side branches that merged into the path. With it, only commits directly between D and M are shown.

git diff — Output Control

--stat

rtk git diff --stat                   # diffstat: file names + ± bar
rtk git diff --stat=<width>,<name-width>,<count>
rtk git diff --compact-summary        # alongside --stat: shows new/gone, +x/-x (executable), +l (symlink)
rtk git diff --numstat                # machine-readable: <added>\t<deleted>\t<path>; - for binary

--name-only / --name-status

Bare git, not rtk git: rtk appends a blank line and a Changes: trailer, so the output is no longer one record per line.

git diff --name-only      # bare per ADR-0023; only filenames, one per line
git diff --name-status    # bare per ADR-0023; status letter + filename per line

--name-status uses the same status letters as --diff-filter.

--word-diff

Bare git, not rtk git: rtk replaces the word-diff with its own diffstat renderer and emits none of the [-removed-] {+added+} markers.

git diff --word-diff             # bare per ADR-0023; inline word-level diff, [-removed-] {+added+} markers
git diff --word-diff=color       # bare per ADR-0023; color only, no markers
git diff --word-diff=porcelain   # bare per ADR-0023; machine-readable: +/- prefixed lines, ~ for newlines
git diff --word-diff-regex=<re>  # bare per ADR-0023; define what counts as a "word"

Whitespace Flags

Flag	Effect
-b / --ignore-space-change	Treat any run of whitespace as equivalent; ignore trailing whitespace
-w / --ignore-all-space	Ignore all whitespace completely
--ignore-space-at-eol	Ignore whitespace at end-of-line only
--ignore-blank-lines	Ignore changes consisting entirely of blank lines
-I<regex> / --ignore-matching-lines=<re>	Ignore changes where all changed lines match regex