GIT-LOG(1) Git Manual GIT-LOG(1)

NAME

git-log - Show commit logs

SYNOPSIS

git log [<options>] [<revision-range>] [[--] <path>...]

DESCRIPTION

Shows the commit logs.

List commits that are reachable by following the parent links from
the given commit(s), but exclude commits that are reachable from the
one(s) given with a ^ in front of them. The output is given in
reverse chronological order by default.

You can think of this as a set operation. Commits reachable from any
of the commits given on the command line form a set, and then commits
reachable from any of the ones given with ^ in front are subtracted
from that set. The remaining commits are what comes out in the
command's output. Various other options and paths parameters can be
used to further limit the result.

Thus, the following command:

$ git log foo bar ^baz

means "list all the commits which are reachable from foo or bar, but
not from baz".

A special notation "<commit1>..<commit2>" can be used as a short-hand
for "^<commit1> <commit2>". For example, either of the following may
be used interchangeably:

$ git log origin..HEAD
$ git log HEAD ^origin

Another special notation is "<commit1>...<commit2>" which is useful
for merges. The resulting set of commits is the symmetric difference
between the two operands. The following two commands are equivalent:

$ git log A B --not $(git merge-base --all A B)
$ git log A...B

The command takes options applicable to the git-rev-list(1) command
to control what is shown and how, and options applicable to the git-
diff(1) command to control how the changes each commit introduces are
shown.

OPTIONS

--follow
Continue listing the history of a file beyond renames (works only
for a single file).

--no-decorate, --decorate[=short|full|auto|no]
Print out the ref names of any commits that are shown. If short
is specified, the ref name prefixes refs/heads/, refs/tags/ and
refs/remotes/ will not be printed. If full is specified, the full
ref name (including prefix) will be printed. If auto is
specified, then if the output is going to a terminal, the ref
names are shown as if short were given, otherwise no ref names
are shown. The option --decorate is short-hand for
--decorate=short. Default to configuration value of log.decorate
if configured, otherwise, auto.

--decorate-refs=<pattern>, --decorate-refs-exclude=<pattern>
For each candidate reference, do not use it for decoration if it
matches any patterns given to --decorate-refs-exclude or if it
doesn't match any of the patterns given to --decorate-refs. The
log.excludeDecoration config option allows excluding refs from
the decorations, but an explicit --decorate-refs pattern will
override a match in log.excludeDecoration.

If none of these options or config settings are given, then
references are used as decoration if they match HEAD,
refs/heads/, refs/remotes/, refs/stash/, or refs/tags/.

--clear-decorations
When specified, this option clears all previous --decorate-refs
or --decorate-refs-exclude options and relaxes the default
decoration filter to include all references. This option is
assumed if the config value log.initialDecorationSet is set to
all.

--source
Print out the ref name given on the command line by which each
commit was reached.

--[no-]mailmap, --[no-]use-mailmap
Use mailmap file to map author and committer names and email
addresses to canonical real names and email addresses. See git-
shortlog(1).

--full-diff
Without this flag, git log -p <path>... shows commits that touch
the specified paths, and diffs about the same specified paths.
With this, the full diff is shown for commits that touch the
specified paths; this means that "<path>..." limits only commits,
and doesn't limit diff for those commits.

Note that this affects all diff-based output types, e.g. those
produced by --stat, etc.

--log-size
Include a line "log size <number>" in the output for each commit,
where <number> is the length of that commit's message in bytes.
Intended to speed up tools that read log messages from git log
output by allowing them to allocate space in advance.

-L<start>,<end>:<file>, -L:<funcname>:<file>
Trace the evolution of the line range given by <start>,<end>, or
by the function name regex <funcname>, within the <file>. You may
not give any pathspec limiters. This is currently limited to a
walk starting from a single revision, i.e., you may only give
zero or one positive revision arguments, and <start> and <end>
(or <funcname>) must exist in the starting revision. You can
specify this option more than once. Implies --patch. Patch output
can be suppressed using --no-patch, but other diff formats
(namely --raw, --numstat, --shortstat, --dirstat, --summary,
--name-only, --name-status, --check) are not currently
implemented.

<start> and <end> can take one of these forms:

+o number

If <start> or <end> is a number, it specifies an absolute
line number (lines count from 1).

+o /regex/

This form will use the first line matching the given POSIX
regex. If <start> is a regex, it will search from the end of
the previous -L range, if any, otherwise from the start of
file. If <start> is ^/regex/, it will search from the start
of file. If <end> is a regex, it will search starting at the
line given by <start>.

+o +offset or -offset

This is only valid for <end> and will specify a number of
lines before or after the line given by <start>.

If :<funcname> is given in place of <start> and <end>, it is a
regular expression that denotes the range from the first funcname
line that matches <funcname>, up to the next funcname line.
:<funcname> searches from the end of the previous -L range, if
any, otherwise from the start of file. ^:<funcname> searches
from the start of file. The function names are determined in the
same way as git diff works out patch hunk headers (see Defining a
custom hunk-header in gitattributes(5)).

<revision-range>
Show only commits in the specified revision range. When no
<revision-range> is specified, it defaults to HEAD (i.e. the
whole history leading to the current commit). origin..HEAD
specifies all the commits reachable from the current commit (i.e.
HEAD), but not from origin. For a complete list of ways to spell
<revision-range>, see the Specifying Ranges section of
gitrevisions(7).

[--] <path>...
Show only commits that are enough to explain how the files that
match the specified paths came to be. See History Simplification
below for details and other simplification modes.

Paths may need to be prefixed with -- to separate them from
options or the revision range, when confusion arises.

Commit Limiting

Besides specifying a range of commits that should be listed using the
special notations explained in the description, additional commit
limiting may be applied.

Using more options generally further limits the output (e.g.
--since=<date1> limits to commits newer than <date1>, and using it
with --grep=<pattern> further limits to commits whose log message has
a line that matches <pattern>), unless otherwise noted.

Note that these are applied before commit ordering and formatting
options, such as --reverse.

-<number>, -n <number>, --max-count=<number>
Limit the number of commits to output.

--skip=<number>
Skip number commits before starting to show the commit output.

--since=<date>, --after=<date>
Show commits more recent than a specific date.

--since-as-filter=<date>
Show all commits more recent than a specific date. This visits
all commits in the range, rather than stopping at the first
commit which is older than a specific date.

--until=<date>, --before=<date>
Show commits older than a specific date.

--author=<pattern>, --committer=<pattern>
Limit the commits output to ones with author/committer header
lines that match the specified pattern (regular expression). With
more than one --author=<pattern>, commits whose author matches
any of the given patterns are chosen (similarly for multiple
--committer=<pattern>).

--grep-reflog=<pattern>
Limit the commits output to ones with reflog entries that match
the specified pattern (regular expression). With more than one
--grep-reflog, commits whose reflog message matches any of the
given patterns are chosen. It is an error to use this option
unless --walk-reflogs is in use.

--grep=<pattern>
Limit the commits output to ones with a log message that matches
the specified pattern (regular expression). With more than one
--grep=<pattern>, commits whose message matches any of the given
patterns are chosen (but see --all-match).

When --notes is in effect, the message from the notes is matched
as if it were part of the log message.

--all-match
Limit the commits output to ones that match all given --grep,
instead of ones that match at least one.

--invert-grep
Limit the commits output to ones with a log message that do not
match the pattern specified with --grep=<pattern>.

-i, --regexp-ignore-case
Match the regular expression limiting patterns without regard to
letter case.

--basic-regexp
Consider the limiting patterns to be basic regular expressions;
this is the default.

-E, --extended-regexp
Consider the limiting patterns to be extended regular expressions
instead of the default basic regular expressions.

-F, --fixed-strings
Consider the limiting patterns to be fixed strings (don't
interpret pattern as a regular expression).

-P, --perl-regexp
Consider the limiting patterns to be Perl-compatible regular
expressions.

Support for these types of regular expressions is an optional
compile-time dependency. If Git wasn't compiled with support for
them providing this option will cause it to die.

--remove-empty
Stop when a given path disappears from the tree.

--merges
Print only merge commits. This is exactly the same as
--min-parents=2.

--no-merges
Do not print commits with more than one parent. This is exactly
the same as --max-parents=1.

--min-parents=<number>, --max-parents=<number>, --no-min-parents,
--no-max-parents
Show only commits which have at least (or at most) that many
parent commits. In particular, --max-parents=1 is the same as
--no-merges, --min-parents=2 is the same as --merges.
--max-parents=0 gives all root commits and --min-parents=3 all
octopus merges.

--no-min-parents and --no-max-parents reset these limits (to no
limit) again. Equivalent forms are --min-parents=0 (any commit
has 0 or more parents) and --max-parents=-1 (negative numbers
denote no upper limit).

--first-parent
When finding commits to include, follow only the first parent
commit upon seeing a merge commit. This option can give a better
overview when viewing the evolution of a particular topic branch,
because merges into a topic branch tend to be only about
adjusting to updated upstream from time to time, and this option
allows you to ignore the individual commits brought in to your
history by such a merge.

This option also changes default diff format for merge commits to
first-parent, see --diff-merges=first-parent for details.

--exclude-first-parent-only
When finding commits to exclude (with a ^), follow only the first
parent commit upon seeing a merge commit. This can be used to
find the set of changes in a topic branch from the point where it
diverged from the remote branch, given that arbitrary merges can
be valid topic branch changes.

--not
Reverses the meaning of the ^ prefix (or lack thereof) for all
following revision specifiers, up to the next --not. When used on
the command line before --stdin, the revisions passed through
stdin will not be affected by it. Conversely, when passed via
standard input, the revisions passed on the command line will not
be affected by it.

--all
Pretend as if all the refs in refs/, along with HEAD, are listed
on the command line as <commit>.

--branches[=<pattern>]
Pretend as if all the refs in refs/heads are listed on the
command line as <commit>. If <pattern> is given, limit branches
to ones matching given shell glob. If pattern lacks ?, *, or [,
/* at the end is implied.

--tags[=<pattern>]
Pretend as if all the refs in refs/tags are listed on the command
line as <commit>. If <pattern> is given, limit tags to ones
matching given shell glob. If pattern lacks ?, *, or [, /* at the
end is implied.

--remotes[=<pattern>]
Pretend as if all the refs in refs/remotes are listed on the
command line as <commit>. If <pattern> is given, limit
remote-tracking branches to ones matching given shell glob. If
pattern lacks ?, *, or [, /* at the end is implied.

--glob=<glob-pattern>
Pretend as if all the refs matching shell glob <glob-pattern> are
listed on the command line as <commit>. Leading refs/, is
automatically prepended if missing. If pattern lacks ?, *, or [,
/* at the end is implied.

--exclude=<glob-pattern>
Do not include refs matching <glob-pattern> that the next --all,
--branches, --tags, --remotes, or --glob would otherwise
consider. Repetitions of this option accumulate exclusion
patterns up to the next --all, --branches, --tags, --remotes, or
--glob option (other options or arguments do not clear
accumulated patterns).

The patterns given should not begin with refs/heads, refs/tags,
or refs/remotes when applied to --branches, --tags, or --remotes,
respectively, and they must begin with refs/ when applied to
--glob or --all. If a trailing /* is intended, it must be given
explicitly.

--exclude-hidden=[fetch|receive|uploadpack]
Do not include refs that would be hidden by git-fetch,
git-receive-pack or git-upload-pack by consulting the appropriate
fetch.hideRefs, receive.hideRefs or uploadpack.hideRefs
configuration along with transfer.hideRefs (see git-config(1)).
This option affects the next pseudo-ref option --all or --glob
and is cleared after processing them.

--reflog
Pretend as if all objects mentioned by reflogs are listed on the
command line as <commit>.

--alternate-refs
Pretend as if all objects mentioned as ref tips of alternate
repositories were listed on the command line. An alternate
repository is any repository whose object directory is specified
in objects/info/alternates. The set of included objects may be
modified by core.alternateRefsCommand, etc. See git-config(1).

--single-worktree
By default, all working trees will be examined by the following
options when there are more than one (see git-worktree(1)):
--all, --reflog and --indexed-objects. This option forces them to
examine the current working tree only.

--ignore-missing
Upon seeing an invalid object name in the input, pretend as if
the bad input was not given.

--bisect
Pretend as if the bad bisection ref refs/bisect/bad was listed
and as if it was followed by --not and the good bisection refs
refs/bisect/good-* on the command line.

--stdin
In addition to getting arguments from the command line, read them
from standard input as well. This accepts commits and
pseudo-options like --all and --glob=. When a -- separator is
seen, the following input is treated as paths and used to limit
the result. Flags like --not which are read via standard input
are only respected for arguments passed in the same way and will
not influence any subsequent command line arguments.

--cherry-mark
Like --cherry-pick (see below) but mark equivalent commits with =
rather than omitting them, and inequivalent ones with +.

--cherry-pick
Omit any commit that introduces the same change as another commit
on the "other side" when the set of commits are limited with
symmetric difference.

For example, if you have two branches, A and B, a usual way to
list all commits on only one side of them is with --left-right
(see the example below in the description of the --left-right
option). However, it shows the commits that were cherry-picked
from the other branch (for example, "3rd on b" may be
cherry-picked from branch A). With this option, such pairs of
commits are excluded from the output.

--left-only, --right-only
List only commits on the respective side of a symmetric
difference, i.e. only those which would be marked < resp. > by
--left-right.

For example, --cherry-pick --right-only A...B omits those commits
from B which are in A or are patch-equivalent to a commit in A.
In other words, this lists the + commits from git cherry A B.
More precisely, --cherry-pick --right-only --no-merges gives the
exact list.

--cherry
A synonym for --right-only --cherry-mark --no-merges; useful to
limit the output to the commits on our side and mark those that
have been applied to the other side of a forked history with git
log --cherry upstream...mybranch, similar to git cherry upstream
mybranch.

-g, --walk-reflogs
Instead of walking the commit ancestry chain, walk reflog entries
from the most recent one to older ones. When this option is used
you cannot specify commits to exclude (that is, ^commit,
commit1..commit2, and commit1...commit2 notations cannot be
used).

With --pretty format other than oneline and reference (for
obvious reasons), this causes the output to have two extra lines
of information taken from the reflog. The reflog designator in
the output may be shown as ref@{<Nth>} (where <Nth> is the
reverse-chronological index in the reflog) or as
ref@{<timestamp>} (with the <timestamp> for that entry),
depending on a few rules:

1. If the starting point is specified as ref@{<Nth>}, show the
index format.

2. If the starting point was specified as ref@{now}, show the
timestamp format.

3. If neither was used, but --date was given on the command
line, show the timestamp in the format requested by --date.

4. Otherwise, show the index format.

Under --pretty=oneline, the commit message is prefixed with this
information on the same line. This option cannot be combined with
--reverse. See also git-reflog(1).

Under --pretty=reference, this information will not be shown at
all.

--merge
Show commits touching conflicted paths in the range
HEAD...<other>, where <other> is the first existing pseudoref in
MERGE_HEAD, CHERRY_PICK_HEAD, REVERT_HEAD or REBASE_HEAD. Only
works when the index has unmerged entries. This option can be
used to show relevant commits when resolving conflicts from a
3-way merge.

--boundary
Output excluded boundary commits. Boundary commits are prefixed
with -.

History Simplification

Sometimes you are only interested in parts of the history, for
example the commits modifying a particular <path>. But there are two
parts of History Simplification, one part is selecting the commits
and the other is how to do it, as there are various strategies to
simplify the history.

The following options select the commits to be shown:

<paths>
Commits modifying the given <paths> are selected.

--simplify-by-decoration
Commits that are referred by some branch or tag are selected.

Note that extra commits can be shown to give a meaningful history.

The following options affect the way the simplification is performed:

Default mode
Simplifies the history to the simplest history explaining the
final state of the tree. Simplest because it prunes some side
branches if the end result is the same (i.e. merging branches
with the same content)

--show-pulls
Include all commits from the default mode, but also any merge
commits that are not TREESAME to the first parent but are
TREESAME to a later parent. This mode is helpful for showing the
merge commits that "first introduced" a change to a branch.

--full-history
Same as the default mode, but does not prune some history.

--dense
Only the selected commits are shown, plus some to have a
meaningful history.

--sparse
All commits in the simplified history are shown.

--simplify-merges
Additional option to --full-history to remove some needless
merges from the resulting history, as there are no selected
commits contributing to this merge.

--ancestry-path[=<commit>]
When given a range of commits to display (e.g. commit1..commit2
or commit2 ^commit1), and a commit <commit> in that range, only
display commits in that range that are ancestors of <commit>,
descendants of <commit>, or <commit> itself. If no commit is
specified, use commit1 (the excluded part of the range) as
<commit>. Can be passed multiple times; if so, a commit is
included if it is any of the commits given or if it is an
ancestor or descendant of one of them.

A more detailed explanation follows.

Suppose you specified foo as the <paths>. We shall call commits that
modify foo !TREESAME, and the rest TREESAME. (In a diff filtered for
foo, they look different and equal, respectively.)

In the following, we will always refer to the same example history to
illustrate the differences between simplification settings. We assume
that you are filtering for a file foo in this commit graph:

.-A---M---N---O---P---Q
/ / / / / /
I B C D E Y
\ / / / / /
`-------------' X

The horizontal line of history A---Q is taken to be the first parent
of each merge. The commits are:

+o I is the initial commit, in which foo exists with contents
"asdf", and a file quux exists with contents "quux". Initial
commits are compared to an empty tree, so I is !TREESAME.

+o In A, foo contains just "foo".

+o B contains the same change as A. Its merge M is trivial and hence
TREESAME to all parents.

+o C does not change foo, but its merge N changes it to "foobar", so
it is not TREESAME to any parent.

+o D sets foo to "baz". Its merge O combines the strings from N and
D to "foobarbaz"; i.e., it is not TREESAME to any parent.

+o E changes quux to "xyzzy", and its merge P combines the strings
to "quux xyzzy". P is TREESAME to O, but not to E.

+o X is an independent root commit that added a new file side, and Y
modified it. Y is TREESAME to X. Its merge Q added side to P,
and Q is TREESAME to P, but not to Y.

rev-list walks backwards through history, including or excluding
commits based on whether --full-history and/or parent rewriting (via
--parents or --children) are used. The following settings are
available.

Default mode
Commits are included if they are not TREESAME to any parent
(though this can be changed, see --sparse below). If the commit
was a merge, and it was TREESAME to one parent, follow only that
parent. (Even if there are several TREESAME parents, follow only
one of them.) Otherwise, follow all parents.

This results in:

.-A---N---O
/ / /
I---------D

Note how the rule to only follow the TREESAME parent, if one is
available, removed B from consideration entirely. C was
considered via N, but is TREESAME. Root commits are compared to
an empty tree, so I is !TREESAME.

Parent/child relations are only visible with --parents, but that
does not affect the commits selected in default mode, so we have
shown the parent lines.

--full-history without parent rewriting
This mode differs from the default in one point: always follow
all parents of a merge, even if it is TREESAME to one of them.
Even if more than one side of the merge has commits that are
included, this does not imply that the merge itself is! In the
example, we get

I A B N D O P Q

M was excluded because it is TREESAME to both parents. E, C and
B were all walked, but only B was !TREESAME, so the others do not
appear.

Note that without parent rewriting, it is not really possible to
talk about the parent/child relationships between the commits, so
we show them disconnected.

--full-history with parent rewriting
Ordinary commits are only included if they are !TREESAME (though
this can be changed, see --sparse below).

Merges are always included. However, their parent list is
rewritten: Along each parent, prune away commits that are not
included themselves. This results in

.-A---M---N---O---P---Q
/ / / / /
I B / D /
\ / / / /
`-------------'

Compare to --full-history without rewriting above. Note that E
was pruned away because it is TREESAME, but the parent list of P
was rewritten to contain E's parent I. The same happened for C
and N, and X, Y and Q.

In addition to the above settings, you can change whether TREESAME
affects inclusion:

--dense
Commits that are walked are included if they are not TREESAME to
any parent.

--sparse
All commits that are walked are included.

Note that without --full-history, this still simplifies merges:
if one of the parents is TREESAME, we follow only that one, so
the other sides of the merge are never walked.

--simplify-merges
First, build a history graph in the same way that --full-history
with parent rewriting does (see above).

Then simplify each commit C to its replacement C' in the final
history according to the following rules:

+o Set C' to C.

+o Replace each parent P of C' with its simplification P'. In
the process, drop parents that are ancestors of other parents
or that are root commits TREESAME to an empty tree, and
remove duplicates, but take care to never drop all parents
that we are TREESAME to.

+o If after this parent rewriting, C' is a root or merge commit
(has zero or >1 parents), a boundary commit, or !TREESAME, it
remains. Otherwise, it is replaced with its only parent.

The effect of this is best shown by way of comparing to
--full-history with parent rewriting. The example turns into:

.-A---M---N---O
/ / /
I B D
\ / /
`---------'

Note the major differences in N, P, and Q over --full-history:

+o N's parent list had I removed, because it is an ancestor of
the other parent M. Still, N remained because it is
!TREESAME.

+o P's parent list similarly had I removed. P was then removed
completely, because it had one parent and is TREESAME.

+o Q's parent list had Y simplified to X. X was then removed,
because it was a TREESAME root. Q was then removed
completely, because it had one parent and is TREESAME.

There is another simplification mode available:

--ancestry-path[=<commit>]
Limit the displayed commits to those which are an ancestor of
<commit>, or which are a descendant of <commit>, or are <commit>
itself.

As an example use case, consider the following commit history:

D---E-------F
/ \ \
B---C---G---H---I---J
/ \
A-------K---------------L--M

A regular D..M computes the set of commits that are ancestors of
M, but excludes the ones that are ancestors of D. This is useful
to see what happened to the history leading to M since D, in the
sense that "what does M have that did not exist in D". The result
in this example would be all the commits, except A and B (and D
itself, of course).

When we want to find out what commits in M are contaminated with
the bug introduced by D and need fixing, however, we might want
to view only the subset of D..M that are actually descendants of
D, i.e. excluding C and K. This is exactly what the
--ancestry-path option does. Applied to the D..M range, it
results in:

E-------F
\ \
G---H---I---J
\
L--M

We can also use --ancestry-path=D instead of --ancestry-path
which means the same thing when applied to the D..M range but is
just more explicit.

If we instead are interested in a given topic within this range,
and all commits affected by that topic, we may only want to view
the subset of D..M which contain that topic in their ancestry
path. So, using --ancestry-path=H D..M for example would result
in:

E
\
G---H---I---J
\
L--M

Whereas --ancestry-path=K D..M would result in

K---------------L--M

Before discussing another option, --show-pulls, we need to create a
new example history.

A common problem users face when looking at simplified history is
that a commit they know changed a file somehow does not appear in the
file's simplified history. Let's demonstrate a new example and show
how options such as --full-history and --simplify-merges works in
that case:

.-A---M-----C--N---O---P
/ / \ \ \/ / /
I B \ R-'`-Z' /
\ / \/ /
\ / /\ /
`---X--' `---Y--'

For this example, suppose I created file.txt which was modified by A,
B, and X in different ways. The single-parent commits C, Z, and Y do
not change file.txt. The merge commit M was created by resolving the
merge conflict to include both changes from A and B and hence is not
TREESAME to either. The merge commit R, however, was created by
ignoring the contents of file.txt at M and taking only the contents
of file.txt at X. Hence, R is TREESAME to X but not M. Finally, the
natural merge resolution to create N is to take the contents of
file.txt at R, so N is TREESAME to R but not C. The merge commits O
and P are TREESAME to their first parents, but not to their second
parents, Z and Y respectively.

When using the default mode, N and R both have a TREESAME parent, so
those edges are walked and the others are ignored. The resulting
history graph is:

I---X

When using --full-history, Git walks every edge. This will discover
the commits A and B and the merge M, but also will reveal the merge
commits O and P. With parent rewriting, the resulting graph is:

.-A---M--------N---O---P
/ / \ \ \/ / /
I B \ R-'`--' /
\ / \/ /
\ / /\ /
`---X--' `------'

Here, the merge commits O and P contribute extra noise, as they did
not actually contribute a change to file.txt. They only merged a
topic that was based on an older version of file.txt. This is a
common issue in repositories using a workflow where many contributors
work in parallel and merge their topic branches along a single trunk:
many unrelated merges appear in the --full-history results.

When using the --simplify-merges option, the commits O and P
disappear from the results. This is because the rewritten second
parents of O and P are reachable from their first parents. Those
edges are removed and then the commits look like single-parent
commits that are TREESAME to their parent. This also happens to the
commit N, resulting in a history view as follows:

.-A---M--.
/ / \
I B R
\ / /
\ / /
`---X--'

In this view, we see all of the important single-parent changes from
A, B, and X. We also see the carefully-resolved merge M and the
not-so-carefully-resolved merge R. This is usually enough information
to determine why the commits A and B "disappeared" from history in
the default view. However, there are a few issues with this approach.

The first issue is performance. Unlike any previous option, the
--simplify-merges option requires walking the entire commit history
before returning a single result. This can make the option difficult
to use for very large repositories.

The second issue is one of auditing. When many contributors are
working on the same repository, it is important which merge commits
introduced a change into an important branch. The problematic merge R
above is not likely to be the merge commit that was used to merge
into an important branch. Instead, the merge N was used to merge R
and X into the important branch. This commit may have information
about why the change X came to override the changes from A and B in
its commit message.

--show-pulls
In addition to the commits shown in the default history, show
each merge commit that is not TREESAME to its first parent but is
TREESAME to a later parent.

When a merge commit is included by --show-pulls, the merge is
treated as if it "pulled" the change from another branch. When
using --show-pulls on this example (and no other options) the
resulting graph is:

I---X---R---N

Here, the merge commits R and N are included because they pulled
the commits X and R into the base branch, respectively. These
merges are the reason the commits A and B do not appear in the
default history.

When --show-pulls is paired with --simplify-merges, the graph
includes all of the necessary information:

.-A---M--. N
/ / \ /
I B R
\ / /
\ / /
`---X--'

Notice that since M is reachable from R, the edge from N to M was
simplified away. However, N still appears in the history as an
important commit because it "pulled" the change R into the main
branch.

The --simplify-by-decoration option allows you to view only the big
picture of the topology of the history, by omitting commits that are
not referenced by tags. Commits are marked as !TREESAME (in other
words, kept after history simplification rules described above) if
(1) they are referenced by tags, or (2) they change the contents of
the paths given on the command line. All other commits are marked as
TREESAME (subject to be simplified away).

Commit Ordering

By default, the commits are shown in reverse chronological order.

--date-order
Show no parents before all of its children are shown, but
otherwise show commits in the commit timestamp order.

--author-date-order
Show no parents before all of its children are shown, but
otherwise show commits in the author timestamp order.

--topo-order
Show no parents before all of its children are shown, and avoid
showing commits on multiple lines of history intermixed.

For example, in a commit history like this:

---1----2----4----7
\ \
3----5----6----8---

where the numbers denote the order of commit timestamps, git
rev-list and friends with --date-order show the commits in the
timestamp order: 8 7 6 5 4 3 2 1.

With --topo-order, they would show 8 6 5 3 7 4 2 1 (or 8 7 4 2 6
5 3 1); some older commits are shown before newer ones in order
to avoid showing the commits from two parallel development track
mixed together.

--reverse
Output the commits chosen to be shown (see Commit Limiting
section above) in reverse order. Cannot be combined with
--walk-reflogs.

Object Traversal

These options are mostly targeted for packing of Git repositories.

--no-walk[=(sorted|unsorted)]
Only show the given commits, but do not traverse their ancestors.
This has no effect if a range is specified. If the argument
unsorted is given, the commits are shown in the order they were
given on the command line. Otherwise (if sorted or no argument
was given), the commits are shown in reverse chronological order
by commit time. Cannot be combined with --graph.

--do-walk
Overrides a previous --no-walk.

Commit Formatting

--pretty[=<format>], --format=<format>
Pretty-print the contents of the commit logs in a given format,
where <format> can be one of oneline, short, medium, full,
fuller, reference, email, raw, format:<string> and
tformat:<string>. When <format> is none of the above, and has
%placeholder in it, it acts as if --pretty=tformat:<format> were
given.

See the "PRETTY FORMATS" section for some additional details for
each format. When =<format> part is omitted, it defaults to
medium.

Note: you can specify the default pretty format in the repository
configuration (see git-config(1)).

--abbrev-commit
Instead of showing the full 40-byte hexadecimal commit object
name, show a prefix that names the object uniquely.
"--abbrev=<n>" (which also modifies diff output, if it is
displayed) option can be used to specify the minimum length of
the prefix.

This should make "--pretty=oneline" a whole lot more readable for
people using 80-column terminals.

--no-abbrev-commit
Show the full 40-byte hexadecimal commit object name. This
negates --abbrev-commit, either explicit or implied by other
options such as "--oneline". It also overrides the
log.abbrevCommit variable.

--oneline
This is a shorthand for "--pretty=oneline --abbrev-commit" used
together.

--encoding=<encoding>
Commit objects record the character encoding used for the log
message in their encoding header; this option can be used to tell
the command to re-code the commit log message in the encoding
preferred by the user. For non plumbing commands this defaults to
UTF-8. Note that if an object claims to be encoded in X and we
are outputting in X, we will output the object verbatim; this
means that invalid sequences in the original commit may be copied
to the output. Likewise, if iconv(3) fails to convert the commit,
we will quietly output the original object verbatim.

--expand-tabs=<n>, --expand-tabs, --no-expand-tabs
Perform a tab expansion (replace each tab with enough spaces to
fill to the next display column that is a multiple of <n>) in the
log message before showing it in the output. --expand-tabs is a
short-hand for --expand-tabs=8, and --no-expand-tabs is a
short-hand for --expand-tabs=0, which disables tab expansion.

By default, tabs are expanded in pretty formats that indent the
log message by 4 spaces (i.e. medium, which is the default,
full, and fuller).

--notes[=<ref>]
Show the notes (see git-notes(1)) that annotate the commit, when
showing the commit log message. This is the default for git log,
git show and git whatchanged commands when there is no --pretty,
--format, or --oneline option given on the command line.

By default, the notes shown are from the notes refs listed in the
core.notesRef and notes.displayRef variables (or corresponding
environment overrides). See git-config(1) for more details.

With an optional <ref> argument, use the ref to find the notes to
display. The ref can specify the full refname when it begins with
refs/notes/; when it begins with notes/, refs/ and otherwise
refs/notes/ is prefixed to form the full name of the ref.

Multiple --notes options can be combined to control which notes
are being displayed. Examples: "--notes=foo" will show only notes
from "refs/notes/foo"; "--notes=foo --notes" will show both notes
from "refs/notes/foo" and from the default notes ref(s).

--no-notes
Do not show notes. This negates the above --notes option, by
resetting the list of notes refs from which notes are shown.
Options are parsed in the order given on the command line, so
e.g. "--notes --notes=foo --no-notes --notes=bar" will only show
notes from "refs/notes/bar".

--show-notes-by-default
Show the default notes unless options for displaying specific
notes are given.

--show-notes[=<ref>], --[no-]standard-notes
These options are deprecated. Use the above --notes/--no-notes
options instead.

--show-signature
Check the validity of a signed commit object by passing the
signature to gpg --verify and show the output.

--relative-date
Synonym for --date=relative.

--date=<format>
Only takes effect for dates shown in human-readable format, such
as when using --pretty. log.date config variable sets a default
value for the log command's --date option. By default, dates are
shown in the original time zone (either committer's or author's).
If -local is appended to the format (e.g., iso-local), the user's
local time zone is used instead.

--date=relative shows dates relative to the current time, e.g.
"2 hours ago". The -local option has no effect for
--date=relative.

--date=local is an alias for --date=default-local.

--date=iso (or --date=iso8601) shows timestamps in a ISO
8601-like format. The differences to the strict ISO 8601 format
are:

+o a space instead of the T date/time delimiter

+o a space between time and time zone

+o no colon between hours and minutes of the time zone

--date=iso-strict (or --date=iso8601-strict) shows timestamps in
strict ISO 8601 format.

--date=rfc (or --date=rfc2822) shows timestamps in RFC 2822
format, often found in email messages.

--date=short shows only the date, but not the time, in YYYY-MM-DD
format.

--date=raw shows the date as seconds since the epoch (1970-01-01
00:00:00 UTC), followed by a space, and then the timezone as an
offset from UTC (a + or - with four digits; the first two are
hours, and the second two are minutes). I.e., as if the timestamp
were formatted with strftime("%s %z")). Note that the -local
option does not affect the seconds-since-epoch value (which is
always measured in UTC), but does switch the accompanying
timezone value.

--date=human shows the timezone if the timezone does not match
the current time-zone, and doesn't print the whole date if that
matches (ie skip printing year for dates that are "this year",
but also skip the whole date itself if it's in the last few days
and we can just say what weekday it was). For older dates the
hour and minute is also omitted.

--date=unix shows the date as a Unix epoch timestamp (seconds
since 1970). As with --raw, this is always in UTC and therefore
-local has no effect.

--date=format:... feeds the format ... to your system strftime,
except for %s, %z, and %Z, which are handled internally. Use
--date=format:%c to show the date in your system locale's
preferred format. See the strftime manual for a complete list of
format placeholders. When using -local, the correct syntax is
--date=format-local:....

--date=default is the default format, and is based on ctime(3)
output. It shows a single line with three-letter day of the week,
three-letter month, day-of-month, hour-minute-seconds in
"HH:MM:SS" format, followed by 4-digit year, plus timezone
information, unless the local time zone is used, e.g. Thu Jan 1
00:00:00 1970 +0000.

--parents
Print also the parents of the commit (in the form "commit
parent..."). Also enables parent rewriting, see History
Simplification above.

--children
Print also the children of the commit (in the form "commit
child..."). Also enables parent rewriting, see History
Simplification above.

--left-right
Mark which side of a symmetric difference a commit is reachable
from. Commits from the left side are prefixed with < and those
from the right with >. If combined with --boundary, those commits
are prefixed with -.

For example, if you have this topology:

y---b---b branch B
/ \ /
/ .
/ / \
o---x---a---a branch A

you would get an output like this:

$ git rev-list --left-right --boundary --pretty=oneline A...B

>bbbbbbb... 3rd on b
>bbbbbbb... 2nd on b
<aaaaaaa... 3rd on a
<aaaaaaa... 2nd on a
-yyyyyyy... 1st on b
-xxxxxxx... 1st on a

--graph
Draw a text-based graphical representation of the commit history
on the left hand side of the output. This may cause extra lines
to be printed in between commits, in order for the graph history
to be drawn properly. Cannot be combined with --no-walk.

This enables parent rewriting, see History Simplification above.

This implies the --topo-order option by default, but the
--date-order option may also be specified.

--show-linear-break[=<barrier>]
When --graph is not used, all history branches are flattened
which can make it hard to see that the two consecutive commits do
not belong to a linear branch. This option puts a barrier in
between them in that case. If <barrier> is specified, it is the
string that will be shown instead of the default one.

PRETTY FORMATS

If the commit is a merge, and if the pretty-format is not oneline,
email or raw, an additional line is inserted before the Author: line.
This line begins with "Merge: " and the hashes of ancestral commits
are printed, separated by spaces. Note that the listed commits may
not necessarily be the list of the direct parent commits if you have
limited your view of history: for example, if you are only interested
in changes related to a certain directory or file.

There are several built-in formats, and you can define additional
formats by setting a pretty.<name> config option to either another
format name, or a format: string, as described below (see git-
config(1)). Here are the details of the built-in formats:

+o oneline

<hash> <title-line>

This is designed to be as compact as possible.

+o short

commit <hash>
Author: <author>

<title-line>

+o medium

commit <hash>
Author: <author>
Date: <author-date>

<title-line>

<full-commit-message>

+o full

commit <hash>
Author: <author>
Commit: <committer>

<title-line>

<full-commit-message>

+o fuller

commit <hash>
Author: <author>
AuthorDate: <author-date>
Commit: <committer>
CommitDate: <committer-date>

<title-line>

<full-commit-message>

+o reference

<abbrev-hash> (<title-line>, <short-author-date>)

This format is used to refer to another commit in a commit
message and is the same as --pretty='format:%C(auto)%h (%s,
%ad)'. By default, the date is formatted with --date=short unless
another --date option is explicitly specified. As with any
format: with format placeholders, its output is not affected by
other options like --decorate and --walk-reflogs.

+o email

From <hash> <date>
From: <author>
Date: <author-date>
Subject: [PATCH] <title-line>

<full-commit-message>

+o mboxrd

Like email, but lines in the commit message starting with "From "
(preceded by zero or more ">") are quoted with ">" so they aren't
confused as starting a new commit.

+o raw

The raw format shows the entire commit exactly as stored in the
commit object. Notably, the hashes are displayed in full,
regardless of whether --abbrev or --no-abbrev are used, and
parents information show the true parent commits, without taking
grafts or history simplification into account. Note that this
format affects the way commits are displayed, but not the way the
diff is shown e.g. with git log --raw. To get full object names
in a raw diff format, use --no-abbrev.

+o format:<format-string>

The format:<format-string> format allows you to specify which
information you want to show. It works a little bit like printf
format, with the notable exception that you get a newline with %n
instead of \n.

E.g, format:"The author of %h was %an, %ar%nThe title was
>>%s<<%n" would show something like this:

The author of fe6e0ee was Junio C Hamano, 23 hours ago
The title was >>t4119: test autocomputing -p<n> for traditional diff input.<<

The placeholders are:

+o Placeholders that expand to a single literal character:

%n
newline

%%
a raw %

%x00
%x followed by two hexadecimal digits is replaced with a
byte with the hexadecimal digits' value (we will call
this "literal formatting code" in the rest of this
document).

+o Placeholders that affect formatting of later placeholders:

%Cred
switch color to red

%Cgreen
switch color to green

%Cblue
switch color to blue

%Creset
reset color

%C(...)
color specification, as described under Values in the
"CONFIGURATION FILE" section of git-config(1). By
default, colors are shown only when enabled for log
output (by color.diff, color.ui, or --color, and
respecting the auto settings of the former if we are
going to a terminal). %C(auto,...) is accepted as a
historical synonym for the default (e.g., %C(auto,red)).
Specifying %C(always,...) will show the colors even when
color is not otherwise enabled (though consider just
using --color=always to enable color for the whole
output, including this format and anything else git might
color). auto alone (i.e. %C(auto)) will turn on auto
coloring on the next placeholders until the color is
switched again.

%m
left (<), right (>) or boundary (-) mark

%w([<w>[,<i1>[,<i2>]]])
switch line wrapping, like the -w option of git-
shortlog(1).

%<( <N> [,trunc|ltrunc|mtrunc])
make the next placeholder take at least N column widths,
padding spaces on the right if necessary. Optionally
truncate (with ellipsis ..) at the left (ltrunc) ..ft,
the middle (mtrunc) mi..le, or the end (trunc) rig.., if
the output is longer than N columns. Note 1: that
truncating only works correctly with N >= 2. Note 2:
spaces around the N and M (see below) values are
optional. Note 3: Emojis and other wide characters will
take two display columns, which may over-run column
boundaries. Note 4: decomposed character combining marks
may be misplaced at padding boundaries.

%<|( <M> )
make the next placeholder take at least until Mth display
column, padding spaces on the right if necessary. Use
negative M values for column positions measured from the
right hand edge of the terminal window.

%>( <N> ), %>|( <M> )
similar to %<( <N> ), %<|( <M> ) respectively, but
padding spaces on the left

%>>( <N> ), %>>|( <M> )
similar to %>( <N> ), %>|( <M> ) respectively, except
that if the next placeholder takes more spaces than given
and there are spaces on its left, use those spaces

%><( <N> ), %><|( <M> )
similar to %<( <N> ), %<|( <M> ) respectively, but
padding both sides (i.e. the text is centered)

+o Placeholders that expand to information extracted from the
commit:

%H
commit hash

%h
abbreviated commit hash

%T
tree hash

%t
abbreviated tree hash

%P
parent hashes

%p
abbreviated parent hashes

%an
author name

%aN
author name (respecting .mailmap, see git-shortlog(1) or
git-blame(1))

%ae
author email

%aE
author email (respecting .mailmap, see git-shortlog(1) or
git-blame(1))

%al
author email local-part (the part before the @ sign)

%aL
author local-part (see %al) respecting .mailmap, see git-
shortlog(1) or git-blame(1))

%ad
author date (format respects --date= option)

%aD
author date, RFC2822 style

%ar
author date, relative

%at
author date, UNIX timestamp

%ai
author date, ISO 8601-like format

%aI
author date, strict ISO 8601 format

%as
author date, short format (YYYY-MM-DD)

%ah
author date, human style (like the --date=human option of
git-rev-list(1))

%cn
committer name

%cN
committer name (respecting .mailmap, see git-shortlog(1)
or git-blame(1))

%ce
committer email

%cE
committer email (respecting .mailmap, see git-shortlog(1)
or git-blame(1))

%cl
committer email local-part (the part before the @ sign)

%cL
committer local-part (see %cl) respecting .mailmap, see
git-shortlog(1) or git-blame(1))

%cd
committer date (format respects --date= option)

%cD
committer date, RFC2822 style

%cr
committer date, relative

%ct
committer date, UNIX timestamp

%ci
committer date, ISO 8601-like format

%cI
committer date, strict ISO 8601 format

%cs
committer date, short format (YYYY-MM-DD)

%ch
committer date, human style (like the --date=human option
of git-rev-list(1))

%d
ref names, like the --decorate option of git-log(1)

%D
ref names without the " (", ")" wrapping.

%(decorate[:<options>])
ref names with custom decorations. The decorate string
may be followed by a colon and zero or more
comma-separated options. Option values may contain
literal formatting codes. These must be used for commas
(%x2C) and closing parentheses (%x29), due to their role
in the option syntax.

+o prefix=<value>: Shown before the list of ref names.
Defaults to " (".

+o suffix=<value>: Shown after the list of ref names.
Defaults to ")".

+o separator=<value>: Shown between ref names. Defaults
to ", ".

+o pointer=<value>: Shown between HEAD and the branch it
points to, if any. Defaults to " -> ".

+o tag=<value>: Shown before tag names. Defaults to
"tag: ".

For example, to produce decorations with no wrapping or tag
annotations, and spaces as separators:

+ %(decorate:prefix=,suffix=,tag=,separator= )

%(describe[:<options>])
human-readable name, like git-describe(1); empty string for
undescribable commits. The describe string may be followed by
a colon and zero or more comma-separated options.
Descriptions can be inconsistent when tags are added or
removed at the same time.

+o tags[=<bool-value>]: Instead of only considering
annotated tags, consider lightweight tags as well.

+o abbrev=<number>: Instead of using the default number of
hexadecimal digits (which will vary according to the
number of objects in the repository with a default of 7)
of the abbreviated object name, use <number> digits, or
as many digits as needed to form a unique object name.

+o match=<pattern>: Only consider tags matching the given
glob(7) pattern, excluding the "refs/tags/" prefix.

+o exclude=<pattern>: Do not consider tags matching the
given glob(7) pattern, excluding the "refs/tags/" prefix.

%S
ref name given on the command line by which the commit was
reached (like git log --source), only works with git log

%e
encoding

%s
subject

%f
sanitized subject line, suitable for a filename

%b
body

%B
raw body (unwrapped subject and body)

%N
commit notes

%GG
raw verification message from GPG for a signed commit

%G?
show "G" for a good (valid) signature, "B" for a bad
signature, "U" for a good signature with unknown validity,
"X" for a good signature that has expired, "Y" for a good
signature made by an expired key, "R" for a good signature
made by a revoked key, "E" if the signature cannot be checked
(e.g. missing key) and "N" for no signature

%GS
show the name of the signer for a signed commit

%GK
show the key used to sign a signed commit

%GF
show the fingerprint of the key used to sign a signed commit

%GP
show the fingerprint of the primary key whose subkey was used
to sign a signed commit

%GT
show the trust level for the key used to sign a signed commit

%gD
reflog selector, e.g., refs/stash@{1} or refs/stash@{2
minutes ago}; the format follows the rules described for the
-g option. The portion before the @ is the refname as given
on the command line (so git log -g refs/heads/master would
yield refs/heads/master@{0}).

%gd
shortened reflog selector; same as %gD, but the refname
portion is shortened for human readability (so
refs/heads/master becomes just master).

%gn
reflog identity name

%gN
reflog identity name (respecting .mailmap, see git-
shortlog(1) or git-blame(1))

%ge
reflog identity email

%gE
reflog identity email (respecting .mailmap, see git-
shortlog(1) or git-blame(1))

%gs
reflog subject

%(trailers[:<options>])
display the trailers of the body as interpreted by git-
interpret-trailers(1). The trailers string may be followed by
a colon and zero or more comma-separated options. If any
option is provided multiple times, the last occurrence wins.

+o key=<key>: only show trailers with specified <key>.
Matching is done case-insensitively and trailing colon is
optional. If option is given multiple times trailer lines
matching any of the keys are shown. This option
automatically enables the only option so that non-trailer
lines in the trailer block are hidden. If that is not
desired it can be disabled with only=false. E.g.,
%(trailers:key=Reviewed-by) shows trailer lines with key
Reviewed-by.

+o only[=<bool>]: select whether non-trailer lines from the
trailer block should be included.

+o separator=<sep>: specify the separator inserted between
trailer lines. Defaults to a line feed character. The
string <sep> may contain the literal formatting codes
described above. To use comma as separator one must use
%x2C as it would otherwise be parsed as next option.
E.g., %(trailers:key=Ticket,separator=%x2C ) shows all
trailer lines whose key is "Ticket" separated by a comma
and a space.

+o unfold[=<bool>]: make it behave as if interpret-trailer's
--unfold option was given. E.g.,
%(trailers:only,unfold=true) unfolds and shows all
trailer lines.

+o keyonly[=<bool>]: only show the key part of the trailer.

+o valueonly[=<bool>]: only show the value part of the
trailer.

+o key_value_separator=<sep>: specify the separator inserted
between the key and value of each trailer. Defaults to ":
". Otherwise it shares the same semantics as
separator=<sep> above.

Note

Some placeholders may depend on other options given to the
revision traversal engine. For example, the %g* reflog options
will insert an empty string unless we are traversing reflog
entries (e.g., by git log -g). The %d and %D placeholders will
use the "short" decoration format if --decorate was not already
provided on the command line.

The boolean options accept an optional value [=<bool-value>]. The
values true, false, on, off etc. are all accepted. See the "boolean"
sub-section in "EXAMPLES" in git-config(1). If a boolean option is
given with no value, it's enabled.

If you add a + (plus sign) after % of a placeholder, a line-feed is
inserted immediately before the expansion if and only if the
placeholder expands to a non-empty string.

If you add a - (minus sign) after % of a placeholder, all consecutive
line-feeds immediately preceding the expansion are deleted if and
only if the placeholder expands to an empty string.

If you add a ` ` (space) after % of a placeholder, a space is
inserted immediately before the expansion if and only if the
placeholder expands to a non-empty string.

+o tformat:

The tformat: format works exactly like format:, except that it
provides "terminator" semantics instead of "separator" semantics.
In other words, each commit has the message terminator character
(usually a newline) appended, rather than a separator placed
between entries. This means that the final entry of a single-line
format will be properly terminated with a new line, just as the
"oneline" format does. For example:

$ git log -2 --pretty=format:%h 4da45bef \
| perl -pe '$_ .= " -- NO NEWLINE\n" unless /\n/'
4da45be
7134973 -- NO NEWLINE

$ git log -2 --pretty=tformat:%h 4da45bef \
| perl -pe '$_ .= " -- NO NEWLINE\n" unless /\n/'
4da45be
7134973

In addition, any unrecognized string that has a % in it is
interpreted as if it has tformat: in front of it. For example,
these two are equivalent:

$ git log -2 --pretty=tformat:%h 4da45bef
$ git log -2 --pretty=%h 4da45bef

DIFF FORMATTING

By default, git log does not generate any diff output. The options
below can be used to show the changes made by each commit.

Note that unless one of --diff-merges variants (including short -m,
-c, --cc, and --dd options) is explicitly given, merge commits will
not show a diff, even if a diff format like --patch is selected, nor
will they match search options like -S. The exception is when
--first-parent is in use, in which case first-parent is the default
format for merge commits.

-p, -u, --patch
Generate patch (see the section called "GENERATING PATCH TEXT
WITH -P").

-s, --no-patch
Suppress all output from the diff machinery. Useful for commands
like git show that show the patch by default to squelch their
output, or to cancel the effect of options like --patch, --stat
earlier on the command line in an alias.

-m
Show diffs for merge commits in the default format. This is
similar to --diff-merges=on, except -m will produce no output
unless -p is given as well.

-c
Produce combined diff output for merge commits. Shortcut for
--diff-merges=combined -p.

--cc
Produce dense combined diff output for merge commits. Shortcut
for --diff-merges=dense-combined -p.

--dd
Produce diff with respect to first parent for both merge and
regular commits. Shortcut for --diff-merges=first-parent -p.

--remerge-diff
Produce remerge-diff output for merge commits. Shortcut for
--diff-merges=remerge -p.

--no-diff-merges
Synonym for --diff-merges=off.

--diff-merges=<format>
Specify diff format to be used for merge commits. Default is
`off` unless --first-parent is in use, in which case first-parent
is the default.

The following formats are supported:

off, none
Disable output of diffs for merge commits. Useful to override
implied value.

on, m
Make diff output for merge commits to be shown in the default
format. The default format can be changed using
log.diffMerges configuration variable, whose default value is
separate.

first-parent, 1
Show full diff with respect to first parent. This is the same
format as --patch produces for non-merge commits.

separate
Show full diff with respect to each of parents. Separate log
entry and diff is generated for each parent.

combined, c
Show differences from each of the parents to the merge result
simultaneously instead of showing pairwise diff between a
parent and the result one at a time. Furthermore, it lists
only files which were modified from all parents.

dense-combined, cc
Further compress output produced by --diff-merges=combined by
omitting uninteresting hunks whose contents in the parents
have only two variants and the merge result picks one of them
without modification.

remerge, r
Remerge two-parent merge commits to create a temporary tree
object--potentially containing files with conflict markers
and such. A diff is then shown between that temporary tree
and the actual merge commit.

The output emitted when this option is used is subject to
change, and so is its interaction with other options (unless
explicitly documented).

--combined-all-paths
Cause combined diffs (used for merge commits) to list the name of
the file from all parents. It thus only has effect when
--diff-merges=[dense-]combined is in use, and is likely only
useful if filename changes are detected (i.e. when either rename
or copy detection have been requested).

-U<n>, --unified=<n>
Generate diffs with <n> lines of context instead of the usual
three. Implies --patch.

--output=<file>
Output to a specific file instead of stdout.

--output-indicator-new=<char>, --output-indicator-old=<char>,
--output-indicator-context=<char>
Specify the character used to indicate new, old or context lines
in the generated patch. Normally they are +, - and ' '
respectively.

--raw
For each commit, show a summary of changes using the raw diff
format. See the "RAW OUTPUT FORMAT" section of git-diff(1). This
is different from showing the log itself in raw format, which you
can achieve with --format=raw.

--patch-with-raw
Synonym for -p --raw.

-t
Show the tree objects in the diff output.

--indent-heuristic
Enable the heuristic that shifts diff hunk boundaries to make
patches easier to read. This is the default.

--no-indent-heuristic
Disable the indent heuristic.

--minimal
Spend extra time to make sure the smallest possible diff is
produced.

--patience
Generate a diff using the "patience diff" algorithm.

--histogram
Generate a diff using the "histogram diff" algorithm.

--anchored=<text>
Generate a diff using the "anchored diff" algorithm.

This option may be specified more than once.

If a line exists in both the source and destination, exists only
once, and starts with <text>, this algorithm attempts to prevent
it from appearing as a deletion or addition in the output. It
uses the "patience diff" algorithm internally.

--diff-algorithm=(patience|minimal|histogram|myers)
Choose a diff algorithm. The variants are as follows:

default, myers
The basic greedy diff algorithm. Currently, this is the
default.

minimal
Spend extra time to make sure the smallest possible diff is
produced.

patience
Use "patience diff" algorithm when generating patches.

histogram
This algorithm extends the patience algorithm to "support
low-occurrence common elements".

For instance, if you configured the diff.algorithm variable to a
non-default value and want to use the default one, then you have
to use --diff-algorithm=default option.

--stat[=<width>[,<name-width>[,<count>]]]
Generate a diffstat. By default, as much space as necessary will
be used for the filename part, and the rest for the graph part.
Maximum width defaults to terminal width, or 80 columns if not
connected to a terminal, and can be overridden by <width>. The
width of the filename part can be limited by giving another width
<name-width> after a comma or by setting
diff.statNameWidth=<name-width>. The width of the graph part can
be limited by using --stat-graph-width=<graph-width> or by
setting diff.statGraphWidth=<graph-width>. Using --stat or
--stat-graph-width affects all commands generating a stat graph,
while setting diff.statNameWidth or diff.statGraphWidth does not
affect git format-patch. By giving a third parameter <count>, you
can limit the output to the first <count> lines, followed by ...
if there are more.

These parameters can also be set individually with
--stat-width=<width>, --stat-name-width=<name-width> and
--stat-count=<count>.

--compact-summary
Output a condensed summary of extended header information such as
file creations or deletions ("new" or "gone", optionally +l if
it's a symlink) and mode changes (+x or -x for adding or removing
executable bit respectively) in diffstat. The information is put
between the filename part and the graph part. Implies --stat.

--numstat
Similar to --stat, but shows number of added and deleted lines in
decimal notation and pathname without abbreviation, to make it
more machine friendly. For binary files, outputs two - instead of
saying 0 0.

--shortstat
Output only the last line of the --stat format containing total
number of modified files, as well as number of added and deleted
lines.

-X [<param>,...], --dirstat[=<param>,...]
Output the distribution of relative amount of changes for each
sub-directory. The behavior of --dirstat can be customized by
passing it a comma separated list of parameters. The defaults are
controlled by the diff.dirstat configuration variable (see git-
config(1)). The following parameters are available:

changes
Compute the dirstat numbers by counting the lines that have
been removed from the source, or added to the destination.
This ignores the amount of pure code movements within a file.
In other words, rearranging lines in a file is not counted as
much as other changes. This is the default behavior when no
parameter is given.

lines
Compute the dirstat numbers by doing the regular line-based
diff analysis, and summing the removed/added line counts.
(For binary files, count 64-byte chunks instead, since binary
files have no natural concept of lines). This is a more
expensive --dirstat behavior than the changes behavior, but
it does count rearranged lines within a file as much as other
changes. The resulting output is consistent with what you get
from the other --*stat options.

files
Compute the dirstat numbers by counting the number of files
changed. Each changed file counts equally in the dirstat
analysis. This is the computationally cheapest --dirstat
behavior, since it does not have to look at the file contents
at all.

cumulative
Count changes in a child directory for the parent directory
as well. Note that when using cumulative, the sum of the
percentages reported may exceed 100%. The default
(non-cumulative) behavior can be specified with the
noncumulative parameter.

<limit>
An integer parameter specifies a cut-off percent (3% by
default). Directories contributing less than this percentage
of the changes are not shown in the output.

Example: The following will count changed files, while ignoring
directories with less than 10% of the total amount of changed
files, and accumulating child directory counts in the parent
directories: --dirstat=files,10,cumulative.

--cumulative
Synonym for --dirstat=cumulative.

--dirstat-by-file[=<param>,...]
Synonym for --dirstat=files,<param>,....

--summary
Output a condensed summary of extended header information such as
creations, renames and mode changes.

--patch-with-stat
Synonym for -p --stat.

-z
Separate the commits with NULs instead of newlines.

Also, when --raw or --numstat has been given, do not munge
pathnames and use NULs as output field terminators.

Without this option, pathnames with "unusual" characters are
quoted as explained for the configuration variable core.quotePath
(see git-config(1)).

--name-only
Show only the name of each changed file in the post-image tree.
The file names are often encoded in UTF-8. For more information
see the discussion about encoding in the git-log(1) manual page.

--name-status
Show only the name(s) and status of each changed file. See the
description of the --diff-filter option on what the status
letters mean. Just like --name-only the file names are often
encoded in UTF-8.

--submodule[=<format>]
Specify how differences in submodules are shown. When specifying
--submodule=short the short format is used. This format just
shows the names of the commits at the beginning and end of the
range. When --submodule or --submodule=log is specified, the log
format is used. This format lists the commits in the range like
git-submodule(1) summary does. When --submodule=diff is
specified, the diff format is used. This format shows an inline
diff of the changes in the submodule contents between the commit
range. Defaults to diff.submodule or the short format if the
config option is unset.

--color[=<when>]
Show colored diff. --color (i.e. without =<when>) is the same as
--color=always. <when> can be one of always, never, or auto.

--no-color
Turn off colored diff. It is the same as --color=never.

--color-moved[=<mode>]
Moved lines of code are colored differently. The <mode> defaults
to no if the option is not given and to zebra if the option with
no mode is given. The mode must be one of:

no
Moved lines are not highlighted.

default
Is a synonym for zebra. This may change to a more sensible
mode in the future.

plain
Any line that is added in one location and was removed in
another location will be colored with color.diff.newMoved.
Similarly color.diff.oldMoved will be used for removed lines
that are added somewhere else in the diff. This mode picks up
any moved line, but it is not very useful in a review to
determine if a block of code was moved without permutation.

blocks
Blocks of moved text of at least 20 alphanumeric characters
are detected greedily. The detected blocks are painted using
either the color.diff.(old|new)Moved color. Adjacent blocks
cannot be told apart.

zebra
Blocks of moved text are detected as in blocks mode. The
blocks are painted using either the color.diff.(old|new)Moved
color or color.diff.(old|new)MovedAlternative. The change
between the two colors indicates that a new block was
detected.

dimmed-zebra
Similar to zebra, but additional dimming of uninteresting
parts of moved code is performed. The bordering lines of two
adjacent blocks are considered interesting, the rest is
uninteresting. dimmed_zebra is a deprecated synonym.

--no-color-moved
Turn off move detection. This can be used to override
configuration settings. It is the same as --color-moved=no.

--color-moved-ws=<mode>,...
This configures how whitespace is ignored when performing the
move detection for --color-moved. These modes can be given as a
comma separated list:

no
Do not ignore whitespace when performing move detection.

ignore-space-at-eol
Ignore changes in whitespace at EOL.

ignore-space-change
Ignore changes in amount of whitespace. This ignores
whitespace at line end, and considers all other sequences of
one or more whitespace characters to be equivalent.

ignore-all-space
Ignore whitespace when comparing lines. This ignores
differences even if one line has whitespace where the other
line has none.

allow-indentation-change
Initially ignore any whitespace in the move detection, then
group the moved code blocks only into a block if the change
in whitespace is the same per line. This is incompatible with
the other modes.

--no-color-moved-ws
Do not ignore whitespace when performing move detection. This can
be used to override configuration settings. It is the same as
--color-moved-ws=no.

--word-diff[=<mode>]
By default, words are delimited by whitespace; see
--word-diff-regex below. The <mode> defaults to plain, and must
be one of:

color
Highlight changed words using only colors. Implies --color.

plain
Show words as [-removed-] and {added}. Makes no attempts to
escape the delimiters if they appear in the input, so the
output may be ambiguous.

porcelain
Use a special line-based format intended for script
consumption. Added/removed/unchanged runs are printed in the
usual unified diff format, starting with a +/-/` ` character
at the beginning of the line and extending to the end of the
line. Newlines in the input are represented by a tilde ~ on a
line of its own.

none
Disable word diff again.

Note that despite the name of the first mode, color is used to
highlight the changed parts in all modes if enabled.

--word-diff-regex=<regex>
Use <regex> to decide what a word is, instead of considering runs
of non-whitespace to be a word. Also implies --word-diff unless
it was already enabled.

Every non-overlapping match of the <regex> is considered a word.
Anything between these matches is considered whitespace and
ignored(!) for the purposes of finding differences. You may want
to append |[^[:space:]] to your regular expression to make sure
that it matches all non-whitespace characters. A match that
contains a newline is silently truncated(!) at the newline.

For example, --word-diff-regex=. will treat each character as a
word and, correspondingly, show differences character by
character.

The regex can also be set via a diff driver or configuration
option, see gitattributes(5) or git-config(1). Giving it
explicitly overrides any diff driver or configuration setting.
Diff drivers override configuration settings.

--color-words[=<regex>]
Equivalent to --word-diff=color plus (if a regex was specified)
--word-diff-regex=<regex>.

--no-renames
Turn off rename detection, even when the configuration file gives
the default to do so.

--[no-]rename-empty
Whether to use empty blobs as rename source.

--check
Warn if changes introduce conflict markers or whitespace errors.
What are considered whitespace errors is controlled by
core.whitespace configuration. By default, trailing whitespaces
(including lines that consist solely of whitespaces) and a space
character that is immediately followed by a tab character inside
the initial indent of the line are considered whitespace errors.
Exits with non-zero status if problems are found. Not compatible
with --exit-code.

--ws-error-highlight=<kind>
Highlight whitespace errors in the context, old or new lines of
the diff. Multiple values are separated by comma, none resets
previous values, default reset the list to new and all is a
shorthand for old,new,context. When this option is not given, and
the configuration variable diff.wsErrorHighlight is not set, only
whitespace errors in new lines are highlighted. The whitespace
errors are colored with color.diff.whitespace.

--full-index
Instead of the first handful of characters, show the full pre-
and post-image blob object names on the "index" line when
generating patch format output.

--binary
In addition to --full-index, output a binary diff that can be
applied with git-apply. Implies --patch.

--abbrev[=<n>]
Instead of showing the full 40-byte hexadecimal object name in
diff-raw format output and diff-tree header lines, show the
shortest prefix that is at least <n> hexdigits long that uniquely
refers the object. In diff-patch output format, --full-index
takes higher precedence, i.e. if --full-index is specified, full
blob names will be shown regardless of --abbrev. Non default
number of digits can be specified with --abbrev=<n>.

-B[<n>][/<m>], --break-rewrites[=[<n>][/<m>]]
Break complete rewrite changes into pairs of delete and create.
This serves two purposes:

It affects the way a change that amounts to a total rewrite of a
file not as a series of deletion and insertion mixed together
with a very few lines that happen to match textually as the
context, but as a single deletion of everything old followed by a
single insertion of everything new, and the number <m> controls
this aspect of the -B option (defaults to 60%). -B/70% specifies
that less than 30% of the original should remain in the result
for Git to consider it a total rewrite (i.e. otherwise the
resulting patch will be a series of deletion and insertion mixed
together with context lines).

When used with -M, a totally-rewritten file is also considered as
the source of a rename (usually -M only considers a file that
disappeared as the source of a rename), and the number <n>
controls this aspect of the -B option (defaults to 50%). -B20%
specifies that a change with addition and deletion compared to
20% or more of the file's size are eligible for being picked up
as a possible source of a rename to another file.

-M[<n>], --find-renames[=<n>]
If generating diffs, detect and report renames for each commit.
For following files across renames while traversing history, see
--follow. If <n> is specified, it is a threshold on the
similarity index (i.e. amount of addition/deletions compared to
the file's size). For example, -M90% means Git should consider a
delete/add pair to be a rename if more than 90% of the file
hasn't changed. Without a % sign, the number is to be read as a
fraction, with a decimal point before it. I.e., -M5 becomes 0.5,
and is thus the same as -M50%. Similarly, -M05 is the same as
-M5%. To limit detection to exact renames, use -M100%. The
default similarity index is 50%.

-C[<n>], --find-copies[=<n>]
Detect copies as well as renames. See also --find-copies-harder.
If <n> is specified, it has the same meaning as for -M<n>.

--find-copies-harder
For performance reasons, by default, -C option finds copies only
if the original file of the copy was modified in the same
changeset. This flag makes the command inspect unmodified files
as candidates for the source of copy. This is a very expensive
operation for large projects, so use it with caution. Giving more
than one -C option has the same effect.

-D, --irreversible-delete
Omit the preimage for deletes, i.e. print only the header but not
the diff between the preimage and /dev/null. The resulting patch
is not meant to be applied with patch or git apply; this is
solely for people who want to just concentrate on reviewing the
text after the change. In addition, the output obviously lacks
enough information to apply such a patch in reverse, even
manually, hence the name of the option.

When used together with -B, omit also the preimage in the
deletion part of a delete/create pair.

-l<num>
The -M and -C options involve some preliminary steps that can
detect subsets of renames/copies cheaply, followed by an
exhaustive fallback portion that compares all remaining unpaired
destinations to all relevant sources. (For renames, only
remaining unpaired sources are relevant; for copies, all original
sources are relevant.) For N sources and destinations, this
exhaustive check is O(N^2). This option prevents the exhaustive
portion of rename/copy detection from running if the number of
source/destination files involved exceeds the specified number.
Defaults to diff.renameLimit. Note that a value of 0 is treated
as unlimited.

--diff-filter=[(A|C|D|M|R|T|U|X|B)...[*]]
Select only files that are Added (A), Copied (C), Deleted (D),
Modified (M), Renamed (R), have their type (i.e. regular file,
symlink, submodule, ...) changed (T), are Unmerged (U), are
Unknown (X), or have had their pairing Broken (B). Any
combination of the filter characters (including none) can be
used. When * (All-or-none) is added to the combination, all paths
are selected if there is any file that matches other criteria in
the comparison; if there is no file that matches other criteria,
nothing is selected.

Also, these upper-case letters can be downcased to exclude. E.g.
--diff-filter=ad excludes added and deleted paths.

Note that not all diffs can feature all types. For instance,
copied and renamed entries cannot appear if detection for those
types is disabled.

-S<string>
Look for differences that change the number of occurrences of the
specified <string> (i.e. addition/deletion) in a file. Intended
for the scripter's use.

It is useful when you're looking for an exact block of code (like
a struct), and want to know the history of that block since it
first came into being: use the feature iteratively to feed the
interesting block in the preimage back into -S, and keep going
until you get the very first version of the block.

Binary files are searched as well.

-G<regex>
Look for differences whose patch text contains added/removed
lines that match <regex>.

To illustrate the difference between -S<regex> --pickaxe-regex
and -G<regex>, consider a commit with the following diff in the
same file:

+ return frotz(nitfol, two->ptr, 1, 0);
...
- hit = frotz(nitfol, mf2.ptr, 1, 0);

While git log -G"frotz\(nitfol" will show this commit, git log
-S"frotz\(nitfol" --pickaxe-regex will not (because the number of
occurrences of that string did not change).

Unless --text is supplied patches of binary files without a
textconv filter will be ignored.

See the pickaxe entry in gitdiffcore(7) for more information.

--find-object=<object-id>
Look for differences that change the number of occurrences of the
specified object. Similar to -S, just the argument is different
in that it doesn't search for a specific string but for a
specific object id.

The object can be a blob or a submodule commit. It implies the -t
option in git-log to also find trees.

--pickaxe-all
When -S or -G finds a change, show all the changes in that
changeset, not just the files that contain the change in
<string>.

--pickaxe-regex
Treat the <string> given to -S as an extended POSIX regular
expression to match.

-O<orderfile>
Control the order in which files appear in the output. This
overrides the diff.orderFile configuration variable (see git-
config(1)). To cancel diff.orderFile, use -O/dev/null.

The output order is determined by the order of glob patterns in
<orderfile>. All files with pathnames that match the first
pattern are output first, all files with pathnames that match the
second pattern (but not the first) are output next, and so on.
All files with pathnames that do not match any pattern are output
last, as if there was an implicit match-all pattern at the end of
the file. If multiple pathnames have the same rank (they match
the same pattern but no earlier patterns), their output order
relative to each other is the normal order.

<orderfile> is parsed as follows:

+o Blank lines are ignored, so they can be used as separators
for readability.

+o Lines starting with a hash ("#") are ignored, so they can be
used for comments. Add a backslash ("\") to the beginning of
the pattern if it starts with a hash.

+o Each other line contains a single pattern.

Patterns have the same syntax and semantics as patterns used for
fnmatch(3) without the FNM_PATHNAME flag, except a pathname also
matches a pattern if removing any number of the final pathname
components matches the pattern. For example, the pattern
"foo*bar" matches "fooasdfbar" and "foo/bar/baz/asdf" but not
"foobarx".

--skip-to=<file>, --rotate-to=<file>
Discard the files before the named <file> from the output (i.e.
skip to), or move them to the end of the output (i.e. rotate
to). These options were invented primarily for the use of the git
difftool command, and may not be very useful otherwise.

-R
Swap two inputs; that is, show differences from index or on-disk
file to tree contents.

--relative[=<path>], --no-relative
When run from a subdirectory of the project, it can be told to
exclude changes outside the directory and show pathnames relative
to it with this option. When you are not in a subdirectory (e.g.
in a bare repository), you can name which subdirectory to make
the output relative to by giving a <path> as an argument.
--no-relative can be used to countermand both diff.relative
config option and previous --relative.

-a, --text
Treat all files as text.

--ignore-cr-at-eol
Ignore carriage-return at the end of line when doing a
comparison.

--ignore-space-at-eol
Ignore changes in whitespace at EOL.

-b, --ignore-space-change
Ignore changes in amount of whitespace. This ignores whitespace
at line end, and considers all other sequences of one or more
whitespace characters to be equivalent.

-w, --ignore-all-space
Ignore whitespace when comparing lines. This ignores differences
even if one line has whitespace where the other line has none.

--ignore-blank-lines
Ignore changes whose lines are all blank.

-I<regex>, --ignore-matching-lines=<regex>
Ignore changes whose all lines match <regex>. This option may be
specified more than once.

--inter-hunk-context=<number>
Show the context between diff hunks, up to the specified <number>
of lines, thereby fusing hunks that are close to each other.
Defaults to diff.interHunkContext or 0 if the config option is
unset.

-W, --function-context
Show whole function as context lines for each change. The
function names are determined in the same way as git diff works
out patch hunk headers (see "Defining a custom hunk-header" in
gitattributes(5)).

--ext-diff
Allow an external diff helper to be executed. If you set an
external diff driver with gitattributes(5), you need to use this
option with git-log(1) and friends.

--no-ext-diff
Disallow external diff drivers.

--textconv, --no-textconv
Allow (or disallow) external text conversion filters to be run
when comparing binary files. See gitattributes(5) for details.
Because textconv filters are typically a one-way conversion, the
resulting diff is suitable for human consumption, but cannot be
applied. For this reason, textconv filters are enabled by default
only for git-diff(1) and git-log(1), but not for git-format-
patch(1) or diff plumbing commands.

--ignore-submodules[=(none|untracked|dirty|all)]
Ignore changes to submodules in the diff generation. all is the
default. Using none will consider the submodule modified when it
either contains untracked or modified files or its HEAD differs
from the commit recorded in the superproject and can be used to
override any settings of the ignore option in git-config(1) or
gitmodules(5). When untracked is used submodules are not
considered dirty when they only contain untracked content (but
they are still scanned for modified content). Using dirty ignores
all changes to the work tree of submodules, only changes to the
commits stored in the superproject are shown (this was the
behavior until 1.7.0). Using all hides all changes to submodules.

--src-prefix=<prefix>
Show the given source <prefix> instead of "a/".

--dst-prefix=<prefix>
Show the given destination <prefix> instead of "b/".

--no-prefix
Do not show any source or destination prefix.

--default-prefix
Use the default source and destination prefixes ("a/" and "b/").
This overrides configuration variables such as diff.noprefix,
diff.srcPrefix, diff.dstPrefix, and diff.mnemonicPrefix (see git-
config(1)).

--line-prefix=<prefix>
Prepend an additional <prefix> to every line of output.

--ita-invisible-in-index
By default entries added by git add -N appear as an existing
empty file in git diff and a new file in git diff --cached. This
option makes the entry appear as a new file in git diff and
non-existent in git diff --cached. This option could be reverted
with --ita-visible-in-index. Both options are experimental and
could be removed in future.

For more detailed explanation on these common options, see also
gitdiffcore(7).

GENERATING PATCH TEXT WITH -P
Running git-diff(1), git-log(1), git-show(1), git-diff-index(1), git-
diff-tree(1), or git-diff-files(1) with the -p option produces patch
text. You can customize the creation of patch text via the
GIT_EXTERNAL_DIFF and the GIT_DIFF_OPTS environment variables (see
git(1)), and the diff attribute (see gitattributes(5)).

What the -p option produces is slightly different from the
traditional diff format:

1. It is preceded by a "git diff" header that looks like this:

diff --git a/file1 b/file2

The a/ and b/ filenames are the same unless rename/copy is
involved. Especially, even for a creation or a deletion,
/dev/null is not used in place of the a/ or b/ filenames.

When a rename/copy is involved, file1 and file2 show the name of
the source file of the rename/copy and the name of the file that
the rename/copy produces, respectively.

2. It is followed by one or more extended header lines:

old mode <mode>
new mode <mode>
deleted file mode <mode>
new file mode <mode>
copy from <path>
copy to <path>
rename from <path>
rename to <path>
similarity index <number>
dissimilarity index <number>
index <hash>`..`<hash> <mode>
File modes <mode> are printed as 6-digit octal numbers including
the file type and file permission bits.

Path names in extended headers do not include the a/ and b/
prefixes.

The similarity index is the percentage of unchanged lines, and
the dissimilarity index is the percentage of changed lines. It is
a rounded down integer, followed by a percent sign. The
similarity index value of 100% is thus reserved for two equal
files, while 100% dissimilarity means that no line from the old
file made it into the new one.

The index line includes the blob object names before and after
the change. The <mode> is included if the file mode does not
change; otherwise, separate lines indicate the old and the new
mode.

3. Pathnames with "unusual" characters are quoted as explained for
the configuration variable core.quotePath (see git-config(1)).

4. All the file1 files in the output refer to files before the
commit, and all the file2 files refer to files after the commit.
It is incorrect to apply each change to each file sequentially.
For example, this patch will swap a and b:

diff --git a/a b/b
rename from a
rename to b
diff --git a/b b/a
rename from b
rename to a

5. Hunk headers mention the name of the function to which the hunk
applies. See "Defining a custom hunk-header" in gitattributes(5)
for details of how to tailor this to specific languages.

COMBINED DIFF FORMAT

Any diff-generating command can take the -c or --cc option to produce
a combined diff when showing a merge. This is the default format when
showing merges with git-diff(1) or git-show(1). Note also that you
can give suitable --diff-merges option to any of these commands to
force generation of diffs in a specific format.

A "combined diff" format looks like this:

diff --combined describe.c
index fabadb8,cc95eb0..4866510
--- a/describe.c
+++ b/describe.c
@@@ -98,20 -98,12 +98,20 @@@
return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
}

- static void describe(char *arg)
-static void describe(struct commit *cmit, int last_one)
++static void describe(char *arg, int last_one)
{
+ unsigned char sha1[20];
+ struct commit *cmit;
struct commit_list *list;
static int initialized = 0;
struct commit_name *n;

+ if (get_sha1(arg, sha1) < 0)
+ usage(describe_usage);
+ cmit = lookup_commit_reference(sha1);
+ if (!cmit)
+ usage(describe_usage);
+
if (!initialized) {
initialized = 1;
for_each_ref(get_name);

1. It is preceded by a "git diff" header, that looks like this (when
the -c option is used):

diff --combined file

or like this (when the --cc option is used):

diff --cc file

2. It is followed by one or more extended header lines (this example
shows a merge with two parents):

index <hash>,<hash>`..__<hash>__
{empty}`mode <mode>,<mode>``..``<mode>
new file mode <mode>
deleted file mode <mode>,<mode>
The mode <mode>,<mode>..<mode> line appears only if at least one
of the <mode> is different from the rest. Extended headers with
information about detected content movement (renames and copying
detection) are designed to work with the diff of two <tree-ish>
and are not used by combined diff format.

3. It is followed by a two-line from-file/to-file header:

--- a/file
+++ b/file

Similar to the two-line header for the traditional unified diff
format, /dev/null is used to signal created or deleted files.

However, if the --combined-all-paths option is provided, instead
of a two-line from-file/to-file, you get an N+1 line
from-file/to-file header, where N is the number of parents in the
merge commit:

--- a/file
--- a/file
--- a/file
+++ b/file

This extended format can be useful if rename or copy detection is
active, to allow you to see the original name of the file in
different parents.

4. Chunk header format is modified to prevent people from
accidentally feeding it to patch -p1. Combined diff format was
created for review of merge commit changes, and was not meant to
be applied. The change is similar to the change in the extended
index header:

@@@ <from-file-range> <from-file-range> <to-file-range> @@@

There are (number of parents + 1) @ characters in the chunk
header for combined diff format.

Unlike the traditional unified diff format, which shows two files A
and B with a single column that has - (minus -- appears in A but
removed in B), + (plus -- missing in A but added to B), or " " (space
-- unchanged) prefix, this format compares two or more files file1,
file2,... with one file X, and shows how X differs from each of
fileN. One column for each of fileN is prepended to the output line
to note how X's line is different from it.

A - character in the column N means that the line appears in fileN
but it does not appear in the result. A + character in the column N
means that the line appears in the result, and fileN does not have
that line (in other words, the line was added, from the point of view
of that parent).

In the above example output, the function signature was changed from
both files (hence two - removals from both file1 and file2, plus ++
to mean one line that was added does not appear in either file1 or
file2). Also, eight other lines are the same from file1 but do not
appear in file2 (hence prefixed with +).

When shown by git diff-tree -c, it compares the parents of a merge
commit with the merge result (i.e. file1..fileN are the parents).
When shown by git diff-files -c, it compares the two unresolved merge
parents with the working tree file (i.e. file1 is stage 2 aka "our
version", file2 is stage 3 aka "their version").

EXAMPLES

git log --no-merges
Show the whole commit history, but skip any merges

git log v2.6.12.. include/scsi drivers/scsi
Show all commits since version v2.6.12 that changed any file in
the include/scsi or drivers/scsi subdirectories

git log --since="2 weeks ago" -- gitk
Show the changes during the last two weeks to the file gitk. The
-- is necessary to avoid confusion with the branch named gitk

git log --name-status release..test
Show the commits that are in the "test" branch but not yet in the
"release" branch, along with the list of paths each commit
modifies.

git log --follow builtin/rev-list.c
Shows the commits that changed builtin/rev-list.c, including
those commits that occurred before the file was given its present
name.

git log --branches --not --remotes=origin
Shows all commits that are in any of local branches but not in
any of remote-tracking branches for origin (what you have that
origin doesn't).

git log master --not --remotes=*/master
Shows all commits that are in local master but not in any remote
repository master branches.

git log -p -m --first-parent
Shows the history including change diffs, but only from the "main
branch" perspective, skipping commits that come from merged
branches, and showing full diffs of changes introduced by the
merges. This makes sense only when following a strict policy of
merging all topic branches when staying on a single integration
branch.

git log -L '/int main/',/^}/:main.c
Shows how the function main() in the file main.c evolved over
time.

git log -3
Limits the number of commits to show to 3.

DISCUSSION

Git is to some extent character encoding agnostic.

+o The contents of the blob objects are uninterpreted sequences of
bytes. There is no encoding translation at the core level.

+o Path names are encoded in UTF-8 normalization form C. This
applies to tree objects, the index file, ref names, as well as
path names in command line arguments, environment variables and
config files (.git/config (see git-config(1)), gitignore(5),
gitattributes(5) and gitmodules(5)).

Note that Git at the core level treats path names simply as
sequences of non-NUL bytes, there are no path name encoding
conversions (except on Mac and Windows). Therefore, using
non-ASCII path names will mostly work even on platforms and file
systems that use legacy extended ASCII encodings. However,
repositories created on such systems will not work properly on
UTF-8-based systems (e.g. Linux, Mac, Windows) and vice versa.
Additionally, many Git-based tools simply assume path names to be
UTF-8 and will fail to display other encodings correctly.

+o Commit log messages are typically encoded in UTF-8, but other
extended ASCII encodings are also supported. This includes
ISO-8859-x, CP125x and many others, but not UTF-16/32, EBCDIC and
CJK multi-byte encodings (GBK, Shift-JIS, Big5, EUC-x, CP9xx
etc.).

Although we encourage that the commit log messages are encoded in
UTF-8, both the core and Git Porcelain are designed not to force
UTF-8 on projects. If all participants of a particular project find
it more convenient to use legacy encodings, Git does not forbid it.
However, there are a few things to keep in mind.

1. git commit and git commit-tree issue a warning if the commit log
message given to it does not look like a valid UTF-8 string,
unless you explicitly say your project uses a legacy encoding.
The way to say this is to have i18n.commitEncoding in .git/config
file, like this:

[i18n]
commitEncoding = ISO-8859-1

Commit objects created with the above setting record the value of
i18n.commitEncoding in their encoding header. This is to help
other people who look at them later. Lack of this header implies
that the commit log message is encoded in UTF-8.

2. git log, git show, git blame and friends look at the encoding
header of a commit object, and try to re-code the log message
into UTF-8 unless otherwise specified. You can specify the
desired output encoding with i18n.logOutputEncoding in
.git/config file, like this:

[i18n]
logOutputEncoding = ISO-8859-1

If you do not have this configuration variable, the value of
i18n.commitEncoding is used instead.

Note that we deliberately chose not to re-code the commit log message
when a commit is made to force UTF-8 at the commit object level,
because re-coding to UTF-8 is not necessarily a reversible operation.

CONFIGURATION

See git-config(1) for core variables and git-diff(1) for settings
related to diff generation.

format.pretty
Default for the --format option. (See Pretty Formats above.)
Defaults to medium.

i18n.logOutputEncoding
Encoding to use when displaying logs. (See Discussion above.)
Defaults to the value of i18n.commitEncoding if set, and UTF-8
otherwise.

Everything above this line in this section isn't included from the
git-config(1) documentation. The content that follows is the same as
what's found there:

log.abbrevCommit
If true, makes git-log(1), git-show(1), and git-whatchanged(1)
assume --abbrev-commit. You may override this option with
--no-abbrev-commit.

log.date
Set the default date-time mode for the log command. Setting a
value for log.date is similar to using git log's --date option.
See git-log(1) for details.

If the format is set to "auto:foo" and the pager is in use,
format "foo" will be used for the date format. Otherwise,
"default" will be used.

log.decorate
Print out the ref names of any commits that are shown by the log
command. If short is specified, the ref name prefixes
refs/heads/, refs/tags/ and refs/remotes/ will not be printed. If
full is specified, the full ref name (including prefix) will be
printed. If auto is specified, then if the output is going to a
terminal, the ref names are shown as if short were given,
otherwise no ref names are shown. This is the same as the
--decorate option of the git log.

log.initialDecorationSet
By default, git log only shows decorations for certain known ref
namespaces. If all is specified, then show all refs as
decorations.

log.excludeDecoration
Exclude the specified patterns from the log decorations. This is
similar to the --decorate-refs-exclude command-line option, but
the config option can be overridden by the --decorate-refs
option.

log.diffMerges
Set diff format to be used when --diff-merges=on is specified,
see --diff-merges in git-log(1) for details. Defaults to
separate.

log.follow
If true, git log will act as if the --follow option was used when
a single <path> is given. This has the same limitations as
--follow, i.e. it cannot be used to follow multiple files and
does not work well on non-linear history.

log.graphColors
A list of colors, separated by commas, that can be used to draw
history lines in git log --graph.

log.showRoot
If true, the initial commit will be shown as a big creation
event. This is equivalent to a diff against an empty tree. Tools
like git-log(1) or git-whatchanged(1), which normally hide the
root commit will now show it. True by default.

log.showSignature
If true, makes git-log(1), git-show(1), and git-whatchanged(1)
assume --show-signature.

log.mailmap
If true, makes git-log(1), git-show(1), and git-whatchanged(1)
assume --use-mailmap, otherwise assume --no-use-mailmap. True by
default.

notes.mergeStrategy
Which merge strategy to choose by default when resolving notes
conflicts. Must be one of manual, ours, theirs, union, or
cat_sort_uniq. Defaults to manual. See the "NOTES MERGE
STRATEGIES" section of git-notes(1) for more information on each
strategy.

This setting can be overridden by passing the --strategy option
to git-notes(1).

notes.<name>.mergeStrategy
Which merge strategy to choose when doing a notes merge into
refs/notes/<name>. This overrides the more general
"notes.mergeStrategy". See the "NOTES MERGE STRATEGIES" section
in git-notes(1) for more information on the available strategies.

notes.displayRef
Which ref (or refs, if a glob or specified more than once), in
addition to the default set by core.notesRef or GIT_NOTES_REF, to
read notes from when showing commit messages with the git log
family of commands.

This setting can be overridden with the GIT_NOTES_DISPLAY_REF
environment variable, which must be a colon separated list of
refs or globs.

A warning will be issued for refs that do not exist, but a glob
that does not match any refs is silently ignored.

This setting can be disabled by the --no-notes option to the git
log family of commands, or by the --notes=<ref> option accepted
by those commands.

The effective value of "core.notesRef" (possibly overridden by
GIT_NOTES_REF) is also implicitly added to the list of refs to be
displayed.

notes.rewrite.<command>
When rewriting commits with <command> (currently amend or
rebase), if this variable is false, git will not copy notes from
the original to the rewritten commit. Defaults to true. See also
"notes.rewriteRef" below.

This setting can be overridden with the GIT_NOTES_REWRITE_REF
environment variable, which must be a colon separated list of
refs or globs.

notes.rewriteMode
When copying notes during a rewrite (see the
"notes.rewrite.<command>" option), determines what to do if the
target commit already has a note. Must be one of overwrite,
concatenate, cat_sort_uniq, or ignore. Defaults to concatenate.

This setting can be overridden with the GIT_NOTES_REWRITE_MODE
environment variable.

notes.rewriteRef
When copying notes during a rewrite, specifies the (fully
qualified) ref whose notes should be copied. May be a glob, in
which case notes in all matching refs will be copied. You may
also specify this configuration several times.

Does not have a default value; you must configure this variable
to enable note rewriting. Set it to refs/notes/commits to enable
rewriting for the default commit notes.

Can be overridden with the GIT_NOTES_REWRITE_REF environment
variable. See notes.rewrite.<command> above for a further
description of its format.

GIT

Part of the git(1) suite

Git 2.48.1 2025-01-13 GIT-LOG(1)